{"cik":354190,"company":{"entity_status":"ACTIVE","filings":[{"accession":"0000354190-26-000209","document":"xslF345X06/form4.xml","filed":"2026-09-17","form":"4","items":"","report_date":"2026-09-15"},{"accession":"0000354190-26-000207","document":"xslF345X06/form4.xml","filed":"2026-09-10","form":"4","items":"","report_date":"2026-09-08"},{"accession":"0000354190-26-000205","document":"xslF345X06/form4.xml","filed":"2026-09-10","form":"4","items":"","report_date":"2026-09-08"},{"accession":"0000354190-26-000203","document":"xslF345X06/form4.xml","filed":"2026-09-04","form":"4","items":"","report_date":"2026-09-02"},{"accession":"0000354190-26-000201","document":"xslF345X06/form4.xml","filed":"2026-09-02","form":"4","items":"","report_date":"2026-09-01"},{"accession":"0000354190-26-000197","document":"ajg-20260824.htm","filed":"2026-08-27","form":"8-K","items":"5.02","report_date":"2026-08-24"},{"accession":"0000354190-26-000199","document":"xslF345X06/form4.xml","filed":"2026-08-26","form":"4","items":"","report_date":"2026-08-24"},{"accession":"0000354190-26-000195","document":"xslF345X06/form4.xml","filed":"2026-08-20","form":"4","items":"","report_date":"2026-08-19"},{"accession":"0000354190-26-000193","document":"xslF345X06/form4.xml","filed":"2026-08-18","form":"4","items":"","report_date":"2026-08-16"},{"accession":"0001628280-26-053489","document":"ajg-20260630.htm","filed":"2026-08-05","form":"10-Q","items":"","report_date":"2026-06-30"},{"accession":"0001628280-26-051070","document":"ajg-20260730.htm","filed":"2026-07-30","form":"8-K","items":"2.02,7.01","report_date":"2026-07-30"},{"accession":"0000354190-26-000184","document":"ajg-20260722.htm","filed":"2026-07-29","form":"8-K","items":"8.01","report_date":"2026-07-22"},{"accession":"0000354190-26-000171","document":"ajg-20260617.htm","filed":"2026-06-17","form":"8-K","items":"7.01","report_date":"2026-06-17"},{"accession":"0000354190-26-000142","document":"ajg-20260512.htm","filed":"2026-05-13","form":"8-K","items":"5.07","report_date":"2026-05-12"},{"accession":"0001628280-26-031592","document":"ajg-20260331.htm","filed":"2026-05-07","form":"10-Q","items":"","report_date":"2026-03-31"},{"accession":"0000354190-26-000132","document":"ajg-20260430.htm","filed":"2026-04-30","form":"8-K","items":"2.02,7.01,9.01","report_date":"2026-04-30"},{"accession":"0000354190-26-000101","document":"ajg-20260323.htm","filed":"2026-03-23","form":"DEF 14A","items":"","report_date":"2026-05-12"},{"accession":"0000354190-26-000073","document":"ajg-20260317.htm","filed":"2026-03-17","form":"8-K","items":"7.01","report_date":"2026-03-17"},{"accession":"0000354190-26-000069","document":"ajg-20260306.htm","filed":"2026-03-12","form":"8-K","items":"5.02","report_date":"2026-03-06"},{"accession":"0001628280-26-008662","document":"ajg-20251231.htm","filed":"2026-02-17","form":"10-K","items":"","report_date":"2025-12-31"},{"accession":"0001193125-26-029407","document":"d38405d8k.htm","filed":"2026-01-29","form":"8-K","items":"2.02,7.01,9.01","report_date":"2026-01-29"},{"accession":"0000354190-25-000054","document":"ajg-20251216.htm","filed":"2025-12-16","form":"8-K","items":"7.01","report_date":"2025-12-16"},{"accession":"0001628280-25-050734","document":"ajg-20250930.htm","filed":"2025-11-10","form":"10-Q","items":"","report_date":"2025-09-30"},{"accession":"0001193125-25-258781","document":"d83473d8k.htm","filed":"2025-10-30","form":"8-K","items":"2.02,7.01,9.01","report_date":"2025-10-30"},{"accession":"0001628280-25-046542","document":"ajg-20250818.htm","filed":"2025-10-28","form":"8-K/A","items":"9.01","report_date":"2025-08-18"},{"accession":"0000354190-25-000037","document":"ajg-20250918.htm","filed":"2025-09-18","form":"8-K","items":"7.01","report_date":"2025-09-18"},{"accession":"0000354190-25-000019","document":"ajg-20250818.htm","filed":"2025-08-18","form":"8-K","items":"2.01,7.01,9.01","report_date":"2025-08-18"},{"accession":"0000354190-25-000011","document":"ajg-20250630.htm","filed":"2025-08-01","form":"10-Q","items":"","report_date":"2025-06-30"},{"accession":"0001193125-25-170602","document":"d37218d8k.htm","filed":"2025-07-31","form":"8-K","items":"2.02,7.01,9.01","report_date":"2025-07-31"},{"accession":"0001193125-25-134909","document":"d89856d8k.htm","filed":"2025-06-04","form":"8-K","items":"7.01","report_date":"2025-06-04"},{"accession":"0001193125-25-119833","document":"d89770d8k.htm","filed":"2025-05-14","form":"8-K","items":"5.07","report_date":"2025-05-13"},{"accession":"0000950170-25-062859","document":"ajg-20250331.htm","filed":"2025-05-02","form":"10-Q","items":"","report_date":"2025-03-31"},{"accession":"0001193125-25-110014","document":"d937401d8k.htm","filed":"2025-05-01","form":"8-K","items":"2.02,7.01,9.01","report_date":"2025-05-01"},{"accession":"0001193125-25-073495","document":"d813689d8k.htm","filed":"2025-04-04","form":"8-K","items":"1.01,2.03,9.01","report_date":"2025-04-03"},{"accession":"0000950170-25-043725","document":"ajg-20250324.htm","filed":"2025-03-24","form":"DEF 14A","items":"","report_date":"2025-03-24"},{"accession":"0001193125-25-058392","document":"d830619d8k.htm","filed":"2025-03-20","form":"8-K","items":"7.01","report_date":"2025-03-20"},{"accession":"0000950170-25-021775","document":"ajg-20241231.htm","filed":"2025-02-18","form":"10-K","items":"","report_date":"2024-12-31"},{"accession":"0001193125-25-017328","document":"d926210d8k.htm","filed":"2025-01-30","form":"8-K","items":"2.02,5.03,7.01,9.01","report_date":"2025-01-29"},{"accession":"0001193125-24-282109","document":"d882725d8k.htm","filed":"2024-12-19","form":"8-K","items":"8.01,9.01","report_date":"2024-12-19"},{"accession":"0001193125-24-275765","document":"d904143d8k.htm","filed":"2024-12-11","form":"8-K","items":"8.01,9.01","report_date":"2024-12-09"}],"former_names":[{"from":"1994-01-25T05:00:00.000Z","name":"GALLAGHER ARTHUR J & CO","to":"2019-08-14T04:00:00.000Z"}],"gleif_parents":[],"headquarters":[{"latitude":41.9747,"longitude":-88.0186,"name":"Itasca","precision":"headquarters locality","source":"wikidata","url":"https://www.wikidata.org/wiki/Q2671295"}],"insiders":[{"accession":"0000354190-26-000209","acquired_disposed":"D","code":"S","date":"2026-09-15","derivative":false,"filed":"2026-09-17","following_shares":"46819.49","form":"4","owners":["CARY RICHARD C"],"plan_10b5_1":false,"price":"252.86","security":"Common Stock","shares":"1000.0"},{"accession":"0000354190-26-000207","acquired_disposed":"A","code":"G","date":"2026-09-08","derivative":false,"filed":"2026-09-10","following_shares":"148093.25","form":"4","owners":["Gallagher Patrick Murphy"],"plan_10b5_1":false,"price":"0.0","security":"Common Stock","shares":"49988.0"},{"accession":"0000354190-26-000205","acquired_disposed":"D","code":"G","date":"2026-09-08","derivative":false,"filed":"2026-09-10","following_shares":"0.0","form":"4","owners":["GALLAGHER J PATRICK JR"],"plan_10b5_1":false,"price":"0.0","security":"Common Stock","shares":"49988.0"},{"accession":"0000354190-26-000203","acquired_disposed":"D","code":"S","date":"2026-09-02","derivative":false,"filed":"2026-09-04","following_shares":"90262.0","form":"4","owners":["Hudson Scott R"],"plan_10b5_1":false,"price":"264.13","security":"Common Stock","shares":"12000.0"},{"accession":"0000354190-26-000203","acquired_disposed":"A","code":"M","date":"2026-09-02","derivative":false,"filed":"2026-09-04","following_shares":"102262.0","form":"4","owners":["Hudson Scott R"],"plan_10b5_1":false,"price":"86.17","security":"Common Stock","shares":"12000.0"},{"accession":"0000354190-26-000203","acquired_disposed":"D","code":"M","date":"2026-09-02","derivative":true,"filed":"2026-09-04","following_shares":"12370.0","form":"4","owners":["Hudson Scott R"],"plan_10b5_1":false,"price":"0.0","security":"Non-qualified Stock Option","shares":"12000.0"},{"accession":"0000354190-26-000201","acquired_disposed":"A","code":"A","date":"2026-09-01","derivative":false,"filed":"2026-09-02","following_shares":"10826.44","form":"4","owners":["Miskel Christopher C."],"plan_10b5_1":false,"price":"262.0","security":"Common Stock","shares":"152.67"},{"accession":"0000354190-26-000199","acquired_disposed":"D","code":"S","date":"2026-08-24","derivative":false,"filed":"2026-08-26","following_shares":"71292.09","form":"4","owners":["Bay Walter D."],"plan_10b5_1":false,"price":"270.08","security":"Common Stock","shares":"12000.0"},{"accession":"0000354190-26-000195","acquired_disposed":"A","code":"M","date":"2026-08-19","derivative":false,"filed":"2026-08-20","following_shares":"25723.41","form":"4","owners":["Mead Christopher E"],"plan_10b5_1":false,"price":"86.17","security":"Common Stock","shares":"3500.0"},{"accession":"0000354190-26-000195","acquired_disposed":"D","code":"S","date":"2026-08-19","derivative":false,"filed":"2026-08-20","following_shares":"22223.41","form":"4","owners":["Mead Christopher E"],"plan_10b5_1":false,"price":"257.03","security":"Common Stock","shares":"3500.0"},{"accession":"0000354190-26-000195","acquired_disposed":"D","code":"M","date":"2026-08-19","derivative":true,"filed":"2026-08-20","following_shares":"7590.0","form":"4","owners":["Mead Christopher E"],"plan_10b5_1":false,"price":"0.0","security":"Non-qualified Stock Option","shares":"3500.0"},{"accession":"0000354190-26-000193","acquired_disposed":"D","code":"F","date":"2026-08-16","derivative":false,"filed":"2026-08-18","following_shares":"4416.67","form":"4","owners":["Bloom Mark H."],"plan_10b5_1":false,"price":"251.21","security":"Common Stock","shares":"606.81"},{"accession":"0000354190-26-000193","acquired_disposed":"A","code":"M","date":"2026-08-16","derivative":false,"filed":"2026-08-18","following_shares":"5023.49","form":"4","owners":["Bloom Mark H."],"plan_10b5_1":false,"price":"0.0","security":"Common Stock","shares":"1280.49"},{"accession":"0000354190-26-000193","acquired_disposed":"D","code":"M","date":"2026-08-16","derivative":true,"filed":"2026-08-18","following_shares":"6017.05","form":"4","owners":["Bloom Mark H."],"plan_10b5_1":false,"price":"0.0","security":"Phantom Stock","shares":"1280.49"},{"accession":"0000354190-26-000187","acquired_disposed":"D","code":"G","date":"2026-08-05","derivative":false,"filed":"2026-08-07","following_shares":"53262.0","form":"4","owners":["Gallagher Patrick Murphy"],"plan_10b5_1":false,"price":"0.0","security":"Common Stock","shares":"23800.0"},{"accession":"0000354190-26-000180","acquired_disposed":"A","code":"M","date":"2026-07-01","derivative":false,"filed":"2026-07-06","following_shares":"68903.38","form":"4","owners":["Jain Vishal"],"plan_10b5_1":false,"price":"229.57","security":"Common Stock","shares":"2162.69"},{"accession":"0000354190-26-000180","acquired_disposed":"D","code":"M","date":"2026-07-01","derivative":true,"filed":"2026-07-06","following_shares":"9725.85","form":"4","owners":["Jain Vishal"],"plan_10b5_1":false,"price":"0.0","security":"Notional Stock Units","shares":"2162.69"},{"accession":"0000354190-26-000178","acquired_disposed":"A","code":"M","date":"2026-07-01","derivative":false,"filed":"2026-07-06","following_shares":"323743.03","form":"4","owners":["GALLAGHER THOMAS JOSEPH"],"plan_10b5_1":false,"price":"229.57","security":"Common Stock","shares":"351.95"},{"accession":"0000354190-26-000178","acquired_disposed":"D","code":"M","date":"2026-07-01","derivative":true,"filed":"2026-07-06","following_shares":"13345.63","form":"4","owners":["GALLAGHER THOMAS JOSEPH"],"plan_10b5_1":false,"price":"0.0","security":"Notional Stock Units","shares":"351.95"},{"accession":"0000354190-26-000175","acquired_disposed":"A","code":"M","date":"2026-07-01","derivative":false,"filed":"2026-07-06","following_shares":"44832.73","form":"4","owners":["Pesch Michael Robert"],"plan_10b5_1":false,"price":"229.57","security":"Common Stock","shares":"355.8"},{"accession":"0000354190-26-000175","acquired_disposed":"D","code":"M","date":"2026-07-01","derivative":true,"filed":"2026-07-06","following_shares":"6134.53","form":"4","owners":["Pesch Michael Robert"],"plan_10b5_1":false,"price":"0.0","security":"Notional Stock Units","shares":"355.8"}],"legal_name":"ARTHUR J. GALLAGHER & CO.","lei":"54930049QLLMPART6V29","lei_status":"ISSUED","lei_updated_at":"2026-10-16T06:27:44Z","names":[{"entity_id":null,"kind":"alias","name":"Gallagher & Co","source":"wikidata"},{"entity_id":null,"kind":"alias","name":"Gallagher Insurance","source":"wikidata"},{"entity_id":null,"kind":"alias","name":"AJ Gallagher","source":"wikidata"}],"parent_exceptions":["direct-parent: no parent LEI supplied","ultimate-parent: no parent LEI supplied"],"parents":[],"wikidata_id":"Q4799191"},"research_built_at":"2026-10-23T06:11:20.354311+00:00","reviewed_events":[],"reviewed_events_coverage":"selective; not a complete event history; accounting series not reconciled","sources":[{"coverage":"8022 issuers; up to 32 recent company reports and 8 ownership-change filings per issuer","id":"sec","license":"SEC public-information reuse","license_url":"https://www.sec.gov/about/privacy-information","name":"SEC submissions","retrieved_at":"2026-10-23T06:12:00.336203+00:00","status":"ok","url":"https://www.sec.gov/search-filings/edgar-application-programming-interfaces"},{"coverage":"1658 unambiguous CIK-linked entities; coverage is incomplete","id":"wikidata","license":"CC0-1.0","license_url":"https://www.wikidata.org/wiki/Wikidata:Licensing","name":"Wikidata structured data","retrieved_at":"2026-10-23T06:12:25.714432+00:00","status":"ok","url":"https://www.wikidata.org/"},{"coverage":"1197 checked identities; 0 unavailable records","id":"gleif","license":"CC0-1.0","license_url":"https://www.gleif.org/en/meta/lei-data-terms-of-use","name":"GLEIF legal entity reference data","retrieved_at":"2026-10-23T06:14:03.968440+00:00","status":"ok","url":"https://www.gleif.org/en/lei-data/gleif-api"},{"coverage":"4 selected series; gaps remain missing","id":"fed","license":"Public domain (selected government series)","license_url":"https://www.federalreserve.gov/disclaimer.htm","name":"Federal Reserve Board H.15","retrieved_at":"2026-10-23T06:27:13.562713+00:00","status":"ok","url":"https://www.federalreserve.gov/releases/h15/"},{"coverage":"9 selected series; gaps remain missing","id":"bls","license":"Public domain","license_url":"https://www.bls.gov/opub/copyright-information.htm","name":"Bureau of Labor Statistics","retrieved_at":"2026-10-23T06:27:14.878114+00:00","status":"ok","url":"https://www.bls.gov/developers/"},{"coverage":"2026 Q3: filings in this completed quarter; not a live transaction feed","id":"insiders","license":"SEC public-information reuse","license_url":"https://www.sec.gov/about/privacy-information","name":"SEC insider transactions","retrieved_at":"2026-10-23T06:12:21.860189+00:00","status":"ok","url":"https://www.sec.gov/data-research/sec-markets-data/insider-transactions-data-sets"}]}