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	$ 339				339
Other comprehensive loss, net of tax	(653)					(653)
Balance at end of period, common equity at Mar. 31, 2021	16,709		0	15,743	940	26
Balance at end of period at Mar. 31, 2021	17,974	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				(2)
Net income	201				201
Other comprehensive loss, net of tax	(1,166)					(1,166)
Balance at end of period, common equity at Mar. 31, 2022	14,808		$ 0	$ 14,740	$ 1,413	$ (1,345)
Balance at end of period at Mar. 31, 2022	$ 16,073	$ 1,265