Derivative Financial Instruments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Derivative [Line Items]
Amount of gain (loss) on de-designated cash flow hedges, net of tax, to be reclassified during the next 12 months	$ 10		$ 10
Amount of gain (loss), net of tax, to be reclassified during the next 12 months	1		1
Right to reclaim cash	113		113		$ 66
Right to reclaim cash, cash collateral	28		28		28
Right to reclaim cash, maintenance margin	85		85		38
Obligation to return cash	79		79		12
De-designated Cash Flow Hedges
Derivative [Line Items]
Unrealized gains (losses) on derivatives			43
Gains (losses) on cash flow hedging relationships reclassified into interest income	4		3
Gains (losses) on fair value hedging relationships recorded in interest income	2		1
Cash Flow Hedges
Derivative [Line Items]
Unrealized gains (losses) on derivatives			(31)		20
Gains (losses) on cash flow hedging relationships reclassified into interest income	10	$ (1)	10	$ (2)
Gains (losses) on fair value hedging relationships recorded in interest income		$ (1)		$ (2)
Derivatives designated as hedging instruments
Derivative [Line Items]
Right to reclaim cash					14
Obligation to return cash	43		43		1
Derivatives not designated as hedging instruments
Derivative [Line Items]
Right to reclaim cash	46		46		33
Obligation to return cash	$ 102		$ 102		$ 29