Common Stock - Additional Information (Details) - USD ($)		1 Months Ended				3 Months Ended		6 Months Ended		30 Months Ended
	Feb. 01, 2017	Jun. 30, 2017	Mar. 31, 2017	Feb. 28, 2017	Jan. 31, 2015	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Dec. 31, 2016	Oct. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation, decrease on earnings per share, basic (in dollars per share)						$ 0	$ 0	$ (0.01)	$ (0.01)
Share-based compensation, Decrease on earnings per share, diluted (in dollars per share)						$ 0	$ 0	$ 0.01	$ 0.01
Share-based Compensation						$ 2,000,000	$ 3,000,000	$ 11,000,000	$ 10,000,000
Tax benefit from options exercised								2,000,000	1,000,000
Total fair value of shares vested								$ 2,000,000	2,000,000
Treasury stock repurchased		12,679,738				12,679,738		12,679,738		12,679,738	11,655,938
Dividend declared (in dollars per share)	$ 0.25
Annual divided declared (in dollars per share)	$ 1.00
Dividend paid (in dollars per share)		$ 0.25	$ 0.25
Cash dividends paid		$ 13,000,000	$ 13,000,000			$ 13,000,000	0	$ 26,000,000	0
Equity Option
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation expense						1,000,000	1,000,000	1,000,000	1,000,000
Stock Option
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Cash received from stock option exercises								6,000,000	4,000,000
Restricted Stock, Restricted Stock Units, Long Term Performance Units, SARs
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation costs		26,000,000				26,000,000		$ 26,000,000		$ 26,000,000
Unrecognized compensation costs, not yet recognized								2 years 12 days
Share-based Compensation						2,000,000	$ 3,000,000	$ 8,000,000	9,000,000
Restricted Stock
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation costs		$ 12,000,000				$ 12,000,000		$ 12,000,000		$ 12,000,000
Unrecognized compensation costs, not yet recognized								1 year 13 months 12 days
Total fair value of restricted shares vested								$ 14,000,000	$ 8,000,000
Common Stock
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Amount authorized to repurchase				$ 400,000,000	$ 350,000,000							$ 200,000,000
Period of time to repurchase common stock				3 years	3 years
Previous authorized amount to repurchase				$ 112,000,000
Number of shares repurchased								1,000,000		9,400,000.0
Value of shares reprchased								$ 60,000,000		$ 498,000,000