Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011 item	Dec. 31, 2012	Dec. 31, 2011
Income Taxes
Income tax expense	$ 415,000	$ 2,119,000	$ 3,973,000	$ 5,897,000
Income tax expenses (benefit) related to foreign operations	900,000	700,000	4,400,000	6,900,000
State income tax expense (benefit)	100,000		200,000	(100,000)
Tax benefit resulting from the release of uncertain tax position in a foreign jurisdiction	600,000		600,000
U.S. federal income tax benefit related to a prior year settlement				(900,000)
Number of foreign tax jurisdictions that imposed new tax laws		2
Income tax expense related to foreign tax jurisdictions that imposed new tax laws which limited the utilization of net operating losses		$ 1,400,000