Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions				2 Months Ended	9 Months Ended
	Nov. 03, 2015	Oct. 05, 2015	Apr. 24, 2015	Nov. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Subsequent event
Amount drawn from term loan facility					$ 300,000
Dividend declared (in dollars per share)			$ 0.06
Shares repurchased					8.3
Value of shares repurchased					$ 44,978	$ 250,037
Subsequent Event
Subsequent event
Dividend declared (in dollars per share)	$ 0.06
Shares repurchased				1.8
Value of shares repurchased				$ 16,700
Remaining number of authorized shares to be repurchased				304.9
Subsequent Event | Five-year term loan facility
Subsequent event
Amount drawn from term loan facility		$ 325,000