Goodwill and Other Intangible Assets - Additional information (Details) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Indefinite-lived Intangible Assets      
Goodwill recorded in acquisition $ 120,642,000    
Impairments to definite lived intangible assets 0 $ 0 $ 0
Amortization expense for definite lived intangible assets 20,900,000 20,300,000 26,300,000
Impairments to indefinite lived intangible assets 0 $ 0 $ 0
USAA AMCO      
Indefinite-lived Intangible Assets      
Goodwill recorded in acquisition 120,600,000    
Indefinite lived intangible assets 770,100,000    
Finite lived intangible assets $ 38,600,000