Schedule of Stockholders Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax	$ (1)	$ 0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ (1)
Common Stock, Shares, Outstanding beginning of period	88,946,704
Issuance of shares pursuant to equity-based plans	$ 0	0
Adjustments Related to Tax Withholding for Share-based Compensation	(1)	(1)
Stockholders' Equity	2,344	2,258
Dividends declared	(28)	(27)
Net Income	$ 73	61
Common Stock, Shares, Outstanding end of period	89,067,858
Stockholders' Equity	$ 2,387	$ 2,291
Common Stock [Member]
Common Stock, Shares, Outstanding beginning of period	88,946,704	88,792,751
Issuances of shares pursuant to equity-based plans	121,154	106,608
Common Stock, Shares, Outstanding end of period	89,067,858	88,899,359
Common Stock Including Additional Paid in Capital [Member]
Issuance of shares pursuant to equity-based plans	$ 0	$ 0
Adjustments Related to Tax Withholding for Share-based Compensation	1	1
Stockholders' Equity	1,201	1,196
Dividends declared	0	0
Stockholders' Equity	1,200	1,195
AOCI Attributable to Parent [Member]
Stockholders' Equity	(7)	(8)
Stock-based compensation	0	0
Dividends declared	0	0
Stockholders' Equity	(8)	(8)
Retained Earnings [Member]
Stockholders' Equity	1,150	1,070
Stock-based compensation	0	0
Dividends declared	(28)	(27)
Net Income	73	61
Stockholders' Equity	$ 1,195	$ 1,104