Consolidated Statements of Comprehensive Income - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 538,000,000	$ 218,000,000	$ 187,000,000
Other comprehensive income (loss), net of tax
Investment securities	51,000,000	48,000,000	(29,000,000)
Derivatives and hedging activities	(5,000,000)	0	(2,000,000)
Other comprehensive income (loss), net of tax	46,000,000	48,000,000	(31,000,000)
Comprehensive income	$ 584,000,000	$ 266,000,000	$ 156,000,000