Subsequent Events (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Apr. 30, 2016	Mar. 31, 2016	Sep. 30, 2015
Subsequent Event [Line Items]
Long-term debt		$ 1,595,018	$ 1,678,268
6.5% Senior Notes | Senior Notes
Subsequent Event [Line Items]
Principal amount repurchased		13,500
Repayments of debt		$ 5,100
Average discount rate		62.20%
Long-term debt		$ 635,018	$ 648,268
6.5% Senior Notes | Senior Notes | Subsequent Event
Subsequent Event [Line Items]
Principal amount repurchased	$ 140,700
Repayments of debt	94,000
Accrued interest	$ 2,300
Average discount rate	34.80%
Long-term debt	$ 495,800