Acquisitions - Additional Information (Detail) (USD $)	3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011 Year	Mar. 31, 2012
Business Acquisition [Line Items]
Preliminary purchase price allocation period, years		1
Business acquisition, revenue recorded	$ 4,600,000
Fair value of contingent liability	7,043,000		8,213,000
Simena
Business Acquisition [Line Items]
Acquisition cost paid to seller, initial cash payment	10,100,000
Additional purchase price consideration	10,800,000
Fair value of contingent liability	8,000,000
Replay
Business Acquisition [Line Items]
Total purchase price	20,200,000
Psytechnics
Business Acquisition [Line Items]
Total purchase price	$ 17,000,000