Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Unrealized gain on cash equivalents, marketable securities and restricted investment, tax benefit	$ 0	$ 0	$ (73)	$ (58)
Unrealized gain (loss) on hedge contracts, tax benefit	$ (23)	$ (39)	$ 88	$ (241)