CONSOLIDATED STATEMENT OF CHANGES IN EQUITY (UNAUDITED) - USD ($) $ in Millions	Total	Preferred stock	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)
Balance at beginning of period at Dec. 31, 2020		$ 1,265
Balance at beginning of period, common equity at Dec. 31, 2020			$ 0	$ 15,746	$ 601	$ 679
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee benefit plans				(3)
Net income	$ 532				532
Cash dividends declared on preferred stock					(38)
Other comprehensive loss, net of tax	(598)					(598)
Balance at end of period, common equity at Jun. 30, 2021	16,919		0	15,743	1,095	81
Balance at end of period at Jun. 30, 2021	18,184	1,265
Balance at beginning of period at Mar. 31, 2021		1,265
Balance at beginning of period, common equity at Mar. 31, 2021			0	15,743	940	26
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee benefit plans				0
Net income	193				193
Cash dividends declared on preferred stock					(38)
Other comprehensive loss, net of tax	55					55
Balance at end of period, common equity at Jun. 30, 2021	16,919		0	15,743	1,095	81
Balance at end of period at Jun. 30, 2021	18,184	1,265
Balance at beginning of period at Dec. 31, 2021	17,040	1,265
Balance at beginning of period, common equity at Dec. 31, 2021	15,775		0	14,742	1,212	(179)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee benefit plans				(5)
Net income	291				291
Cash dividends declared on preferred stock					(38)
Other comprehensive loss, net of tax	(1,751)					(1,751)
Balance at end of period, common equity at Jun. 30, 2022	14,272		0	14,737	1,465	(1,930)
Balance at end of period at Jun. 30, 2022	15,537	1,265
Balance at beginning of period at Mar. 31, 2022		1,265
Balance at beginning of period, common equity at Mar. 31, 2022			0	14,740	1,413	(1,345)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee benefit plans				(3)
Net income	90				90
Cash dividends declared on preferred stock					(38)
Other comprehensive loss, net of tax	(585)					(585)
Balance at end of period, common equity at Jun. 30, 2022	14,272		$ 0	$ 14,737	$ 1,465	$ (1,930)
Balance at end of period at Jun. 30, 2022	$ 15,537	$ 1,265