Intangible Assets - Schedule of Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013
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	24,215	23,610
Accumulated amortization	(22,148)	(21,527)
Net carrying amount	2,067	2,083
Unamortized intangible assets:
Accumulated impairment	(900)	(900)
Carrying amount	9,200	9,200
Total intangible assets, gross carrying amount	33,415	32,810
Intangible Assets, Net (Excluding Goodwill)	11,267	11,283
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	10,775	10,775
Accumulated amortization, excluding accumulated impairment	(9,630)	(9,179)
Net carrying amount, excluding accumulated impairment	1,145	1,596
Non-competition agreements [Member]
Amortized intangible assets:
Gross carrying amount, excluding accumulated impairment	2,700	2,700
Accumulated amortization, excluding accumulated impairment	(2,343)	(2,213)
Net carrying amount, excluding accumulated impairment	357	487
Developed technology [Member]
Amortized intangible assets:
Gross carrying amount, excluding accumulated impairment	20,153	19,548
Accumulated amortization, excluding accumulated impairment	(10,095)	(10,055)
Net carrying amount, excluding accumulated impairment	10,058	9,493
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