Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Basic and diluted net earnings per share:
Net income		$ 74	$ 86	$ 138	$ 135
Shares
Weighted average common shares outstanding		181,422,000	183,328,000	181,735,000	183,917,000
Add: Participating securities	[1]	52,000	49,000	49,000	45,000
Weighted average common shares outstanding - Basic (in shares)		181,474,000	183,377,000	181,784,000	183,962,000
Plus incremental shares from assumed conversions:
Weighted average common shares outstanding - Diluted (in shares)		182,313,000	184,519,000	182,688,000	185,144,000
Basic earnings per share (usd per share)		$ 0.41	$ 0.47	$ 0.76	$ 0.74
Diluted earnings per share (usd per share)		$ 0.41	$ 0.47	$ 0.76	$ 0.73
Stock Options
Plus incremental shares from assumed conversions:
Dilutive effect of common shares	[2]	513,000	659,000	522,000	659,000
Restricted Stock
Plus incremental shares from assumed conversions:
Dilutive effect of common shares	[2]	326,000	483,000	382,000	523,000

[1] Restricted stock awards containing rights to non-forfeitable dividends that participate in undistributed earnings with common shareholders are considered participating securities for purposes of computing earnings per share.

[2] Incremental shares from stock options, restricted stock and performance share units are computed by the treasury stock method. The weighted average shares listed below were not included in the computation of diluted earnings per share because to do so would have been anti-dilutive for the periods presented or were otherwise excluded under the treasury stock method. The treasury stock method calculates dilution assuming the exercise of all in-the-money options and vesting of restricted stock and performance share awards, reduced by the repurchase of shares with the proceeds from the assumed exercises, unrecognized compensation expense for outstanding awards and the estimated tax benefit of the assumed exercises. Performance share units will be included in the treasury stock calculation of diluted earnings per share upon achievement of underlying performance conditions. See Note 14, "Share-Based Compensation Plans" for further detail on the performance share units.