Acquisitions - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013 Entity	Mar. 31, 2012	Mar. 31, 2011 Entity
Business Acquisition [Line Items]
Number of acquisitions	4		3
Combined net purchase price	$ 23,553		$ 32,200
Goodwill relating to acquisitions	16,764	16,399
Trademarks
Business Acquisition [Line Items]
Acquired intangible assets	2,000		1,774
Noncompete Agreements
Business Acquisition [Line Items]
Acquired intangible assets	500
Customer Relationships
Business Acquisition [Line Items]
Acquired intangible assets	3,400		3,547
Technology
Business Acquisition [Line Items]
Acquired intangible assets	4,265		2,741
Acquired Companies
Business Acquisition [Line Items]
Goodwill relating to acquisitions			$ 15,342