Details of Sales (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Revenues From External Customers And Long Lived Assets [Line Items]
Sales	$ 68,288	$ 78,148	$ 76,420	$ 77,751	$ 36,949	$ 55,201	$ 56,233	$ 43,281	$ 300,607	$ 191,664	$ 172,970
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Sales									300,131	216,741	155,781
Canada
Revenues From External Customers And Long Lived Assets [Line Items]
Sales									39,415	23,741	8,966
Colombia
Revenues From External Customers And Long Lived Assets [Line Items]
Sales									608
Russian Federation
Revenues From External Customers And Long Lived Assets [Line Items]
Sales									10,758	9,837	10,144
United Kingdom
Revenues From External Customers And Long Lived Assets [Line Items]
Sales									2,021	4,064	4,883
Eliminations
Revenues From External Customers And Long Lived Assets [Line Items]
Sales									$ (52,326)	$ (62,719)	$ (6,804)