Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2019
Feb. 19, 2020
Jun. 28, 2019
Document and Entity Information [Abstract]      
Entity Central Index Key 0000883948    
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Entity File Number 0-20293    
Entity Tax Identification Number 54-1598552    
Entity Incorporation, State or Country Code VA    
Entity Address, Address Line One 1051 East Cary Street    
Entity Address, Address Line Two Suite 1200    
Entity Address, City or Town Richmond    
Entity Address, State or Province VA    
Entity Address, Postal Zip Code 23219    
City Area Code 804    
Local Phone Number 633-5031    
Title of 12(b) Security Common Stock, par value $1.33 per share    
Trading Symbol AUB    
Security Exchange Name NASDAQ    
Document Period End Date Dec. 31, 2019    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Amendment Flag false    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2019    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Voluntary Filers No    
Entity Well-known Seasoned Issuer Yes    
Entity Public Float     $ 2,850,450,474
Entity Common Stock, Shares Outstanding   79,216,981