Consolidated Statements of Comprehensive Income (Unaudited) - USD ($)	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Consolidated Statements of Comprehensive Income (Unaudited) [Abstract]
Net income	$ 7,508,000	$ 1,910,000
Other comprehensive (loss) income, net of tax:
Unrealized gain (loss) on short-term investments (net of tax of $15,000 and $(4,000))	22,000	(6,000)
Foreign currency translation loss	(535,000)	(349,000)
Total other comprehensive loss, net of tax	(513,000)	(355,000)
Comprehensive income	$ 6,995,000	$ 1,555,000