Consolidated Statement Of Equity - USD ($) shares in Thousands, $ in Millions	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Common Stock [Member]	Total
Balance at Dec. 31, 2015					$ (353)
Net loss							$ (293)
Other comprehensive income, net of tax							(50)
Balance at Sep. 30, 2016					(403)
Balance at Dec. 31, 2015					(353)
Cumulative Effect Adjustment from adoption of ASU 2016-09				$ 1			1
Balance at Dec. 31, 2016		$ 20	$ 5,561	(460)	(387)	$ (215)	$ 4,519
Preferred Stock Balance (in shares) at Dec. 31, 2016	19,250
Common Stock Balance (in shares) at Dec. 31, 2016		79,532				(1,362)	78,170
Stock plans (in shares)						292
Stock plans			(57)			$ 64	$ 7
Dividends on common stock			(219)				(219)
Dividends on preferred stock			(161)				(161)
Net loss				(775)			(775)
Pension settlement costs, net of tax					48		48
Other comprehensive income, net of tax					(10)		(10)
Balance at Sep. 30, 2017		$ 20	$ 5,124	$ (1,234)	$ (349)	$ (151)	$ 3,410
Preferred Stock Balance (in shares) at Sep. 30, 2017	19,250
Common Stock Balance (in shares) at Sep. 30, 2017		79,532				(1,070)	78,462