Goodwill and Intangibles Asset Rollforward (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended		9 Months Ended
		Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2015	Mar. 31, 2014
Goodwill and Intangible Assets [Line Items]
Goodwill	[1]	$ 2,794	$ 2,794	$ 2,794	$ 2,794	$ 2,794	$ 2,794	$ 2,794
Gross balance								69,191
Amortizable Intangibles, Accumulated amortization								(34,466)
Finite-lived Intangible Assets [Roll Forward]
Net balance		30,098	32,739	33,550	31,891	34,725	31,891
Additions			171	132		395
Amortization expense		(850)	(1,019)	(943)	(1,793)	(1,570)
Net balance		29,248	31,891	32,739	30,098	33,550	29,248
North America [Member]
Goodwill and Intangible Assets [Line Items]
Goodwill		2,794					$ 2,794
Customer Relationships Intangible [Member]
Goodwill and Intangible Assets [Line Items]
Weighted average remaining useful life in years							9 years 3 months
Amortizable Intangibles, Gross carrying amount								33,700
Amortizable Intangibles, Accumulated amortization								(14,954)
Finite-lived Intangible Assets [Roll Forward]
Net balance		16,219	17,482	17,903	17,061	18,746	$ 17,061
Additions			0	0		0
Amortization expense		(421)	(421)	(421)	(842)	(843)
Net balance		15,798	17,061	17,482	16,219	17,903	$ 15,798
Production and Supply Contract Intangibles [Member]
Goodwill and Intangible Assets [Line Items]
Weighted average remaining useful life in years							5 years
Amortizable Intangibles, Gross carrying amount								14,893
Amortizable Intangibles, Accumulated amortization								(4,752)
Finite-lived Intangible Assets [Roll Forward]
Net balance		8,565	9,491	9,808	9,107	10,141	$ 9,107
Additions			0	0		0
Amortization expense		(237)	(384)	(317)	(542)	(333)
Net balance		8,328	9,107	9,491	8,565	9,808	$ 8,328
Internally Developed Software Intangible [Member]
Goodwill and Intangible Assets [Line Items]
Weighted average remaining useful life in years							0 years
Amortizable Intangibles, Gross carrying amount								17,804
Amortizable Intangibles, Accumulated amortization								$ (14,760)
Finite-lived Intangible Assets [Roll Forward]
Net balance		2,520	2,972	3,045	2,929	3,044	$ 2,929
Additions			171	132		395
Amortization expense		(192)	(214)	(205)	(409)	(394)
Net balance		$ 2,328	$ 2,929	$ 2,972	$ 2,520	$ 3,045	$ 2,328

[1] Goodwill of $2,794 relates to the North America segment.