Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Common Stock Held in Treasury, at Cost [Member]	Noncontrolling Interest [Member]	Parent Company [Member]	Parent Company [Member] Retained Earnings [Member]	Parent Company [Member] AOCI Attributable to Parent [Member]	Parent Company [Member] Additional Paid-in Capital [Member]	Parent Company [Member] Common Stock Held in Treasury, at Cost [Member]
Beginning balance at Dec. 31, 2016	$ 1,978	$ 1,558	$ (39)	$ 0	$ 0	$ 195	$ 0	$ 264
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)	(335)	(329)	(7)	0	0	0	0	0	$ (335)	$ (329)	$ (7)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | Accounting Standards Update 2018-02 [Domain]									0	7	(7)
Cost of warrants acquired	4					4			4			$ 4
Issuance of common stock	(2)	(2)					0	0	(2)	(2)			$ 0
Ending balance at Dec. 31, 2017	1,645	1,234	(52)	0	0	200	0	264
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)	274	267	6	0	0	0	0	0	192	186	6
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	0			0	0	0	0	0	0
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | Accounting Standards Update 2016-01 [Member]		3	(3)
Cost of warrants acquired	12	0	0	0	0	12	0	0	12			12	0
Issuance of common stock	(1)	(1)	0	0	0	0	0	0	(1)	(1)			0
Ending balance at Dec. 31, 2018	1,633	1,421	(49)	0	0	219	0	41
Increase (Decrease) in Stockholders' Equity [Roll Forward]
AMPS Impact on Stockholders Equity	(297)	(82)	0	0	0	8	0	(223)	8			8
Total comprehensive income (loss)	(125)	(216)	91	0	0	0	0	0	(125)	(216)	$ 91
Cost of warrants acquired	12	0	0	0	0	12	0	0	12			$ 12
Issuance of common stock	(3)	(3)	0	0	0	0	0	0	$ (3)	$ (3)			$ 0
Ending balance at Dec. 31, 2019	1,536	1,203	42	0	0	232	0	60
Increase (Decrease) in Stockholders' Equity [Roll Forward]
AMPS Impact on Stockholders Equity	$ 19	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 19