Consolidated Statements of Shareholder's Equity - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	[1]	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment
Beginning Balance at Dec. 31, 2019	$ 2,587	$ 119		$ 0	$ 161	$ (1,087)	$ 3,513	$ 119
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	22						22
Other comprehensive income (loss)	(137)					(137)
Ending Balance at Mar. 31, 2020	2,591			0	161	(1,224)	3,654
Beginning Balance at Dec. 31, 2020	2,895			0	161	(1,099)	3,833
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	140						140
Other comprehensive income (loss)	(9)					(9)
Ending Balance at Mar. 31, 2021	$ 3,026			$ 0	$ 161	$ (1,108)	$ 3,973

[1] Represents $140 million, net of tax of $21 million, related to the impact as of January 1, 2020, of adopting the Current Expected Credit Loss (CECL) Methodology for the recognition of credit losses on certain financial instruments.