Parent Company Financial Information - Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net income attributable to controlling interest	$ 900	$ 999	$ 845
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Deferred income tax expense (benefit)	91	0	(18)
Stock-based compensation expense	75	43	32
Loss on extinguishment of debt	0	26	0
Gain on sale of title services business	(22)	0	0
Total adjustments	1,399	(269)	(685)
Net cash provided by operating activities	2,311	741	172
Securities:
Proceeds from sales and prepayments of securities	0	68	629
Purchases of securities
Proceeds from business divestitures, net	22	0	0
Net cash provided by (used in) investing activities	8,313	(4,617)	(4,967)
Preferred stock:
Proceeds from issuance of preferred stock	494	145	144
Call of preferred stock	0	(100)	0
Cash dividends paid - preferred stock	(32)	(33)	(17)
Common stock:
Stock options exercised	36	28	7
Cash dividends paid	(324)	(333)	(222)
Repurchase of shares	(12)	(416)	(4)
Term borrowings:
Net cash provided by (used in) financing activities	(10,869)	4,016	5,176
Net increase (decrease) in cash and cash equivalents	(245)	140	381
Cash and cash equivalents at beginning of period	1,788	1,648	1,267
Cash and cash equivalents at end of period	1,543	1,788	1,648
Total interest paid	280	170	261
Income taxes received from subsidiaries	20	258	105
Parent Company
Operating activities:
Net income attributable to controlling interest	900	999	845
Less undistributed net income of subsidiaries	555	340	740
Income before undistributed net income of subsidiaries	345	659	105
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Deferred income tax expense (benefit)	7	8	5
Stock-based compensation expense	76	43	32
Loss on extinguishment of debt	0	26	0
Gain on sale of title services business	(22)	0	0
Other operating activities, net	2	(11)	25
Total adjustments	63	66	62
Net cash provided by operating activities	408	725	167
Securities:
Proceeds from sales and prepayments of securities	8	3	0
Purchases of securities
Purchases of securities	(1)	(10)	(5)
Sales (purchases) of premises and equipment	13	8	(2)
Cash received for business combination, net	0	0	103
Net cash provided by (used in) investing activities	42	1	96
Preferred stock:
Proceeds from issuance of preferred stock	494	145	144
Call of preferred stock	0	(100)	0
Cash dividends paid - preferred stock	(32)	(33)	(17)
Common stock:
Stock options exercised	36	28	7
Cash dividends paid	(324)	(333)	(222)
Repurchase of shares	(13)	(416)	(4)
Proceeds from issuance of term borrowings	0	0	795
Term borrowings:
Repayment of term borrowings	0	(120)	(500)
Other financing activities, net	0	0	(8)
Net cash provided by (used in) financing activities	161	(829)	195
Net increase (decrease) in cash and cash equivalents	611	(103)	458
Cash and cash equivalents at beginning of period	724	827	369
Cash and cash equivalents at end of period	1,335	724	827
Total interest paid	35	35	33
Income taxes received from subsidiaries	$ 42	$ 28	$ 33