Details of Revenue (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
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 16,008	$ 19,751	$ 27,942	$ 21,166	$ 26,285	$ 40,728	$ 68,551	$ 101,348	$ 84,867	$ 236,912	$ 300,607
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									77,487	230,818	300,131
Canada
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									4,796	39,064	39,415
Colombia
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									609	3,222	608
Russian Federation
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									5,554	14,048	10,758
United Kingdom
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									2,644	2,229	2,021
Eliminations
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue									$ (6,223)	$ (52,469)	$ (52,326)