Summary of Significant Accounting Policies Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Consolidated Statement of Cash Flow
Net income (loss)	$ (5,974)	$ 33,878	$ 10,609	$ 35,906	$ (141,140)	$ 33,267	$ 9,900	$ 53,821	$ 74,418	$ (44,152)	$ 136,910
Deferred income taxes									(30,261)	(48,881)	(2,137)
Net cash provided by operating activities									290,519	102,744	311,576
As Reported
Consolidated Statement of Cash Flow
Net income (loss)									$ 74,418	$ (44,152)	129,480
Deferred income taxes											5,293
Net cash provided by operating activities											311,576
Adjustment
Consolidated Statement of Cash Flow
Net income (loss)			$ 2,647	$ 2,284							7,430
Deferred income taxes											$ (7,430)