XML 12 R1.htm IDEA: XBRL DOCUMENT v3.19.2
Document and Entity Information
 6 Months Ended
Jun. 30, 2019
shares
Document and Entity Information [Abstract]  
Amendment Flag false
Document Type 10-Q
Document Fiscal Year Focus 2019
Entity Interactive Data Current Yes
Document Fiscal Period Focus Q2
Document Quarterly Report true
Entity Central Index Key 0000354190
Document Transition Report false
Current Fiscal Year End Date --12-31
Document Period End Date Jun. 30, 2019
Entity Registrant Name GALLAGHER ARTHUR J & CO
Entity File Number 1-09761
Entity Tax Identification Number 36-2151613
Entity Incorporation, State or Country Code DE
Entity Current Reporting Status Yes
Entity Shell Company false
Entity Filer Category Large Accelerated Filer
Entity Small Business false
Entity Emerging Growth Company false
Entity Address, Address Line One 2850 W. Golf Road
Entity Address, City or Town Rolling Meadows
Entity Address, State or Province IL
Entity Address, Postal Zip Code 60008-4050
City Area Code 630
Local Phone Number 773-3800
Trading Symbol AJG
Security Exchange Name NYSE
Title of 12(b) Security Common Stock
Entity Common Stock, Shares Outstanding 186,070,000