Borrowings - Breakdown of FHLB Advances Outstanding (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Total short-term Federal Home Loan Bank advances and other borrowings	$ 3,301	$ 1,880
Long-term fixed rate advances	700	1,400
Total	$ 4,001	$ 3,280
Rate	1.43%	0.90%
Short-term fixed rate term advances
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal home loan bank, advances, maturities summary, due in next rolling twelve months	$ 3,300	$ 1,600
Rate	1.54%	0.19%
Other short-term borrowings
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Federal home loan bank, advances, maturities summary, due in next rolling twelve months	$ 1	$ 280
Rate	1.90%	0.11%