CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 314	$ 449	$ 601	$ 1,341
Other comprehensive income (loss):
Net unrealized derivative instruments (losses) gains arising during the periods, net of income taxes of $0, ($1), $30 and $35, respectively	0	(4)	88	103
Reclassification adjustment for net derivative (gains) losses included in net income, net of income taxes of ($15), $4, ($27) and $13, respectively	(42)	10	(79)	40
Net unrealized debt securities (losses) gains arising during the periods, net of income taxes of ($14), $13, $131 and $165, respectively	(44)	42	405	509
Other-than-temporary impairment not recognized in earnings on debt securities, net of income taxes of $0, $0, $0 and $0, respectively	0	(1)	0	0
Reclassification of net debt securities gains to net income, net of income taxes of $0, $0, ($1) and ($3), respectively	(1)	(2)	(3)	(10)
Amortization of actuarial loss, net of income taxes of $1, $2, $2 and $5, respectively	3	3	10	9
Net other comprehensive income	(84)	48	421	651
Total comprehensive income	$ 230	$ 497	$ 1,022	$ 1,992