Capital Stock (Details) - USD ($)					3 Months Ended		9 Months Ended		36 Months Ended
	Dec. 01, 2016	Nov. 01, 2016	Sep. 07, 2016	Jul. 12, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Feb. 04, 2016	May 27, 2014	Sep. 18, 2013
Class of Stock [Line Items]
Cash dividends paid							$ 56,000,000	$ 49,000,000
Cash dividends declared (dollars per share)					$ 0.17	$ 0.06	$ 0.31	$ 0.18
Payments for repurchase of stock							$ 200,000,000	$ 82,000,000
Common Stock
Class of Stock [Line Items]
Cash dividends paid							$ 56,000,000
Cash dividends declared, date declared			Sep. 07, 2016
Cash dividends declared (dollars per share)			$ 0.1	$ 0.07
Increase in cash dividends declared (dollars per share)			$ 0.03
Cash dividends declared			$ 26,000,000
Stock repurchase program, authorized amount										$ 1,100,000,000.0	$ 450,000,000	$ 100,000,000
Shares repurchased					1,734,404		6,897,034		21,404,752
Average price of shares repurchased (dollars per share)					$ 28.83		$ 29.00		$ 28.66
Payments for repurchase of stock					$ 50,000,000		$ 200,000,000		$ 613,000,000
Scenario, Forecast | Common Stock
Class of Stock [Line Items]
Dividends payable, date to be paid	Dec. 01, 2016
Dividends payable, date of record		Nov. 01, 2016