CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 34	$ 439
Other comprehensive income (loss):
Net unrealized derivative instruments gains arising during the periods, net of income taxes of $33 and $13, respectively	96	39
Reclassification adjustment for net derivative (gains) losses included in net income, net of income taxes of ($1) and $5, respectively	(3)	15
Net unrealized debt securities gains arising during the periods, net of income taxes of $129 and $80, respectively	400	246
Reclassification of net debt securities gains to net income, net of income taxes of $0 and ($2), respectively	0	(5)
Amortization of actuarial loss, net of income taxes of $1 and $2, respectively	3	3
Net other comprehensive income	496	298
Total comprehensive income	$ 530	$ 737