Schedule of Stockholders Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Common Stock, Shares, Outstanding beginning of period	89,267,959
Issuance of shares pursuant to equity-based plans	$ 0	$ 0
Stockholders' Equity	2,506	2,416
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	1
Dividends declared	(32)	(30)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	73	64
Reclassification of stranded tax effects due to Tax Reform	$ (2)
Common Stock, Shares, Outstanding end of period	89,356,311
Stockholders' Equity	$ 2,548	$ 2,449
Common Stock [Member]
Common Stock, Shares, Outstanding beginning of period	89,267,959	89,114,265
Issuances of shares pursuant to equity-based plans	88,352	99,854
Common Stock, Shares, Outstanding end of period	89,356,311	89,214,119
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)
Stockholders' Equity	1,212	1,207
Dividends declared	0	0
Stockholders' Equity	1,212	1,206
AOCI Attributable to Parent [Member]
Stockholders' Equity	(7)	(8)
Stock-based compensation		0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	1
Dividends declared	0	0
Reclassification of stranded tax effects due to Tax Reform	(2)
Stockholders' Equity	(8)	(8)
Retained Earnings [Member]
Stockholders' Equity	1,301	1,217
Stock-based compensation		0
Dividends declared	(32)	(30)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		64
Stockholders' Equity	$ 1,344	$ 1,251