Acquisitions (Narrative) (Details) (USD $)	12 Months Ended
	Mar. 31, 2012 Y	Mar. 31, 2011	Mar. 31, 2010
Business Acquisition [Line Items]
Preliminary purchase price allocation period, years, maximum	1
Weighted average useful life in years of identifiable intangible assets	10.8
Business acquisition, revenue recorded	$ 5,500,000
Fair value of contingent liability	8,213,000	0	0
Simena [Member]
Business Acquisition [Line Items]
Acquisition cost paid to seller, initial cash payment	10,100,000
Additional purchase price consideration	10,800,000
Total purchase price	18,086,000
Weighted average useful life in years of identifiable intangible assets	10
Acquisition-related costs	160,000
Fair value of contingent liability	8,000,000
Replay [Member]
Business Acquisition [Line Items]
Total purchase price	20,237,000
Weighted average useful life in years of identifiable intangible assets	8.6
Acquisition-related costs	807,000
Psytechnics [Member]
Business Acquisition [Line Items]
Total purchase price	17,014,000
Net asset balance reserved	3,300,000
Weighted average useful life in years of identifiable intangible assets	8.6
Acquisition-related costs	$ 1,000,000