Derivative Financial Instruments (Offsetting Liabilities) (Detail) - Liability - USD ($) $ in Millions		Mar. 31, 2022	Dec. 31, 2021
Derivative [Line Items]
Gross liabilities presented in the consolidated balance sheet	[1]	$ 10	$ 19
Gross amounts not offset in the consolidated balance sheet, financial instruments		0	0
Gross amounts not offset in the consolidated balance sheet, cash collateral paid		6	11
Gross amounts not offset in the consolidated balance sheet, net amounts		4	8
Interest Rate Contract [Member] | Over The Counter [Member]
Derivative [Line Items]
Gross liabilities presented in the consolidated balance sheet	[1]	10	19
Gross amounts not offset in the consolidated balance sheet, financial instruments		0	0
Gross amounts not offset in the consolidated balance sheet, cash collateral paid		6	11
Gross amounts not offset in the consolidated balance sheet, net amounts		$ 4	$ 8

[1] There were no derivative liabilities that are not subject to master netting or similar arrangements at March 31, 2022 or December 31, 2021.