Consolidated Statements Of Equity - USD ($) $ in Millions	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Common Stock [Member]	Total
Balance, beginning at Dec. 31, 2013		$ 257	$ 4,321	$ 76	$ (261)	$ (338)	$ 4,055
Balance (in shares) at Dec. 31, 2013		1,027,986,000				(28,524,000)
Stock plans			(30)			$ 44	14
Stock plans (in shares)						3,007,000
Dividends on common stock			(301)	(100)			(401)
Net income (loss)				133			133
Other comprehensive income (loss), net of tax					(143)		(143)
Balance, ending at Dec. 31, 2014		$ 257	3,990	109	(404)	$ (294)	3,658
Balance (in shares) at Dec. 31, 2014		1,027,986,000				(25,517,000)
Issuance of stock (in shares)	19,250,000	165,000,000
Issuance of common stock		$ 41	758				799
Issuance of preferred stock			1,866				1,866
Stock plans			(4)			$ 16	12
Stock plans (in shares)						731,000
Dividends on common stock			(456)				(456)
Dividends on preferred stock			(120)				(120)
Net income (loss)				(196)			(196)
Other comprehensive income (loss), net of tax					51		$ 51
Preferred Stock Balance (in shares) at Dec. 31, 2015	19,250,000						19,250,000
Balance, ending at Dec. 31, 2015		$ 298	6,034	(87)	(353)	$ (278)	$ 5,614
Balance (in shares) at Dec. 31, 2015		1,192,986,000				(24,786,000)	1,168,200,000
Stock plans			(44)			$ 63	$ 19
Stock plans (in shares)						4,353,000
Dividends on common stock			(493)				(493)
Dividends on preferred stock			(214)				(214)
Net income (loss)				(373)			(373)
Other comprehensive income (loss), net of tax					(34)		$ (34)
Preferred Stock Balance (in shares) at Dec. 31, 2016	19,250,000						19,250,000
Balance, ending at Dec. 31, 2016		$ 298	$ 5,283	$ (460)	$ (387)	$ (215)	$ 4,519
Balance (in shares) at Dec. 31, 2016		1,192,986,000				(20,433,000)	1,172,553,000