Preferred Stock (Schedule of Equity Units) (Parenthetical) (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Capital Unit [Line Items]
Issuance costs			$ 28
Corporate units stock purchase contract liability payments	$ 85	$ 83	38
Stock Purchase Contract Liability	44	129
Preferred Stock
Capital Unit [Line Items]
Issuance costs			14
Recorded dividend	$ 28	$ 28	$ 15
Dividends per share	$ 17.50	$ 17.50	$ 9.479
Common Stock
Capital Unit [Line Items]
Issuance costs			$ 14