Schedule of Stockholders Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Common Stock, Shares, Outstanding beginning of period	89,387,124
Issuance of shares pursuant to equity-based plans	$ 0	$ 0
Stockholders' Equity	2,591	2,506
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	1	1
Dividends declared	(35)	(32)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 81	73
Reclassification of stranded tax effects due to Tax Reform		0
Common Stock, Shares, Outstanding end of period	89,464,521
Stockholders' Equity	$ 2,638	$ 2,548
Common Stock [Member]
Common Stock, Shares, Outstanding beginning of period	89,387,124	89,267,959
Issuances of shares pursuant to equity-based plans	77,397	88,352
Common Stock, Shares, Outstanding end of period	89,464,521	89,356,311
Common Stock Including Additional Paid in Capital [Member]
Issuance of shares pursuant to equity-based plans	$ 0	$ 0
Stockholders' Equity	1,220	1,212
Dividends declared	0	0
Stockholders' Equity	1,220	1,212
AOCI Attributable to Parent [Member]
Stockholders' Equity	(10)	(7)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	1	1
Dividends declared	0	0
Reclassification of stranded tax effects due to Tax Reform		(2)
Stockholders' Equity	(9)	(8)
Retained Earnings [Member]
Stockholders' Equity	1,381	1,301
Dividends declared	35	32
Reclassification of stranded tax effects due to Tax Reform		(2)
Stockholders' Equity	$ 1,427	$ 1,344