v3.19.3.a.u2
Other Assets - Additional Information (Detail) - PennyMac [Member] - USD ($)
shares in Millions, $ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Other Assets [Line Items]    
Ownership percentage 20.00%  
Shares 16  
Carrying value - equity method investment $ 451 $ 397
Market value of equity method investments $ 530 $ 331