Schedule of Stockholders Equity (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Common Stock, Shares, Outstanding beginning of period	88,946,704
Issuance of shares pursuant to equity-based plans	$ 1	$ 1
Adjustments Related to Tax Withholding for Share-based Compensation	1	1
Stockholders' Equity	2,344	2,258
Dividends declared	(59)	(55)
Net Income	$ 105	98
Common Stock, Shares, Outstanding end of period	89,062,560
Stockholders' Equity	$ 2,392	$ 2,303
Common Stock [Member]
Common Stock, Shares, Outstanding beginning of period	88,946,704	88,792,751
Issuances of shares pursuant to equity-based plans	115,856	128,005
Common Stock, Shares, Outstanding end of period	89,062,560	88,920,756
Common Stock Including Additional Paid in Capital [Member]
Issuance of shares pursuant to equity-based plans	$ 1	$ 1
Adjustments Related to Tax Withholding for Share-based Compensation	1	1
Stockholders' Equity	1,201	1,196
Dividends declared	0	0
Stockholders' Equity	1,203	1,198
AOCI Attributable to Parent [Member]
Stockholders' Equity	(7)	(8)
Stock-based compensation	0	0
Dividends declared	0	0
Stockholders' Equity	(7)	(8)
Retained Earnings [Member]
Stockholders' Equity	1,150	1,070
Stock-based compensation	0	0
Dividends declared	(59)	(55)
Net Income	105	98
Stockholders' Equity	$ 1,196	$ 1,113