Schedule of Stockholders Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Common Stock, Shares, Outstanding beginning of period	89,114,265
Issuance of shares pursuant to equity-based plans	$ 0	$ 0
Adjustments Related to Tax Withholding for Share-based Compensation	(1)	(1)
Stockholders' Equity	2,416	2,344
Dividends declared	(30)	(28)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		(1)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	64	73
Net Income	$ 64	73
Common Stock, Shares, Outstanding end of period	89,214,119
Stockholders' Equity	$ 2,449	$ 2,387
Common Stock [Member]
Common Stock, Shares, Outstanding beginning of period	89,114,265	88,946,704
Issuances of shares pursuant to equity-based plans	99,854	121,154
Common Stock, Shares, Outstanding end of period	89,214,119	89,067,858
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	1,207	1,201
Dividends declared	0	0
Stockholders' Equity	1,206	1,200
AOCI Attributable to Parent [Member]
Stockholders' Equity	(8)	(7)
Stock-based compensation	0	0
Dividends declared	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent		(1)
Stockholders' Equity	(8)	(8)
Retained Earnings [Member]
Stockholders' Equity	1,217	1,150
Stock-based compensation	0	0
Dividends declared	(30)	(28)
Net Income		73
Stockholders' Equity	$ 1,251	$ 1,195