CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 648	$ 253	$ 1,259	$ 287
Other comprehensive income (loss):
Net unrealized derivative instruments gains (losses) arising during the periods, net of income taxes of $16, $(3), $9 and $30, respectively	46	(8)	25	88
Reclassification of net derivative (gains) losses included in net income, net of income taxes of $(10), $(11), $(19) and $(12), respectively	(27)	(34)	(52)	(37)
Net unrealized debt securities gains (losses) arising during the periods, net of income taxes of $3, $16, $(97) and $145, respectively	10	49	(297)	449
Reclassification of net debt securities (gains) losses to net income, net of income taxes of $0, $(1), $(1) and $(1), respectively	(3)	(2)	(5)	(2)
Amortization of actuarial loss, net of income taxes of $1, $0, $1 and $1, respectively	4	4	8	7
Total other comprehensive income (loss), net of income taxes	30	9	(321)	505
Total comprehensive income (loss)	$ 678	$ 262	$ 938	$ 792