Goodwill and Intangible Assets - Schedule of Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Amortized intangible assets:
Gross carrying amount, accumulated impairment	$ (9,493)	$ (9,493)
Accumulated amortization, accumulated impairment	0	0
Net carrying amount, accumulated impairment	(9,493)	(9,493)
Gross carrying amount	31,634	26,495
Accumulated amortization	(23,546)	(21,560)
Net carrying amount	8,088	4,935
Unamortized intangible assets:
Accumulated impairment	(900)	(900)
Carrying amount	9,200	9,200
Total intangible assets, gross carrying amount	40,834	35,695
Total intangible assets, net carrying amount	17,288	14,135
Trade names [Member]
Unamortized intangible assets:
Carrying amount, excluding accumulated impairment	10,100	10,100
Customer relationships [Member]
Amortized intangible assets:
Gross carrying amount, excluding accumulated impairment	12,475	12,475
Accumulated amortization, excluding accumulated impairment	(10,880)	(9,979)
Net carrying amount, excluding accumulated impairment	1,595	2,496
Non-competition agreements [Member]
Amortized intangible assets:
Gross carrying amount, excluding accumulated impairment	2,910	2,910
Accumulated amortization, excluding accumulated impairment	(2,422)	(2,162)
Net carrying amount, excluding accumulated impairment	488	748
Developed technology [Member]
Amortized intangible assets:
Gross carrying amount, excluding accumulated impairment	19,876	19,578
Accumulated amortization, excluding accumulated impairment	(10,164)	(9,339)
Net carrying amount, excluding accumulated impairment	9,712	10,239
Patented Technology [Member]
Amortized intangible assets:
Gross carrying amount, excluding accumulated impairment	80	80
Accumulated amortization, excluding accumulated impairment	(80)	(80)
Net carrying amount, excluding accumulated impairment	0	0
Project expenditures not yet in use [Member]
Amortized intangible assets:
Gross carrying amount, excluding accumulated impairment	5,786	945
Accumulated amortization, excluding accumulated impairment	0	0
Net carrying amount, excluding accumulated impairment	$ 5,786	$ 945