Income Loss Before Provision for Income Taxes and Provision for Income Taxes (Detail) (USD $)	3 Months Ended								12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Income Taxes [Line Items]
Income (loss) before income tax provision	$ 4,140,000	$ 3,243,000	$ 5,924,000	$ 3,555,000	$ 2,928,000	$ 3,287,000	$ 826,000	$ (4,498,000)	$ 16,862,000	$ 2,543,000	$ (10,863,000)
Current income tax provision, Federal									97,000		(78,000)
Current income tax provision, State											81,000
Current income tax provision, Foreign									996,000	259,000
Current income tax provision									1,093,000	259,000	3,000
Deferred income tax provision, Federal									825,000	825,000	825,000
Deferred income tax provision, State									(70,000)	(36,000)	64,000
Deferred income tax provision, Foreign
Deferred income tax provision									755,000	789,000	889,000
Total income tax provision	398,000	559,000	455,000	436,000	361,000	366,000	225,000	96,000	1,848,000	1,048,000	892,000
UNITED STATES
Income Taxes [Line Items]
Income (loss) before income tax provision									10,202,000	236,000	(6,522,000)
Foreign
Income Taxes [Line Items]
Income (loss) before income tax provision									$ 6,660,000	$ 2,307,000	$ (4,341,000)