CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Millions	Total	Adoption of new accounting standard [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Adoption of new accounting standard [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance at beginning of period at Dec. 31, 2019	$ 4,883		$ 107	$ 3	$ 4,067	$ 798		$ (65)	$ (27)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	67					47		20
Dividends declared:
Preferred stock	(2)					(2)
Common stock	(39)					(39)
Repurchase of common stock	(25)								(25)
Restricted stock compensation	8				8
Balance at end of period at Mar. 31, 2020	4,842	$ (50)	107	3	4,075	754	$ (50)	(45)	(52)
Balance at beginning of period at Dec. 31, 2020	4,959		107	3	4,087	869		(39)	(68)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	81					93		(12)
Dividends declared:
Preferred stock	(2)					(2)
Common stock	(39)					(39)
Issuance of common stock	0				1				(1)
Repurchase of common stock	(36)								(36)
Restricted stock compensation	11				11
Balance at end of period at Mar. 31, 2021	$ 4,974		$ 107	$ 3	$ 4,099	$ 921		$ (51)	$ (105)