Mortgage Banking Activity - Residential Mortgage Loans (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at beginning of period	$ 590
Balance at end of period	789	$ 590
Mortgage loans
Loans Receivable Held-for-sale, Net, Reconciliation to Cash Flow [Roll Forward]
Balance at beginning of period	44	250
Originations and purchases	299	1,275
Sales, net of gains	(255)	(1,481)
Mortgage loans transferred from (to) held for investment	0	0
Balance at end of period	$ 88	$ 44