Income Taxes (Details) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Taxes
Income tax expense	$ 1,320,000	$ 1,787,000	$ 2,900,000	$ 3,558,000
Income tax expenses (benefit) related to foreign operations	1,300,000	1,800,000	2,800,000	3,500,000
State income tax expense.			100,000	100,000
U.S. federal income tax benefit	$ 0	$ 0	$ 0	$ 0