Consolidated Statement of Shareholder's Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]
Beginning balance at Dec. 31, 2017	$ 1,871		$ 161	$ (998)	$ 2,708
Net income	129	$ 0			129
Other comprehensive income	10			10
Ending balance at Mar. 31, 2018	2,010		161	(988)	2,837
Beginning balance at Dec. 31, 2018	2,196		161	(1,060)	3,095
Net income	103	$ 0			103
Other comprehensive income	7			7
Ending balance at Mar. 31, 2019	$ 2,306		$ 161	$ (1,053)	$ 3,198