Condensed Consolidated Statement of Equity (Unaudited) - 6 months ended Sep. 30, 2016 - USD ($) $ in Thousands	Total	Common Stock [Member]	Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest in Subsidiary [Member]
Beginning balance at Mar. 31, 2016	$ 1,134,424	$ 5	$ 855,387	$ 273,704	$ 7	$ 5,321
Beginning balance, shares at Mar. 31, 2016		48,926,417
Exercise of stock options	9,595		9,595
Exercise of stock options, shares		221,237
Issuance of stock under Employee Stock Purchase Plan	4,892		4,892
Issuance of stock under Employee Stock Purchase Plan, shares		94,339
Stock-based compensation	28,617		28,617
Shares issued in settlement of certain accrued employee compensation liabilities	13,080		13,080
Shares issued in settlement of certain accrued employee compensation liabilities, shares		176,731
RSU awards vesting, net of shares withheld for taxes which have been retired	(2,504)		(2,504)
RSU awards vesting, net of shares withheld for taxes which have been retired, shares		67,899
Other noncontrolling interest activity	(15)					(15)
Net income	12,896			12,874		22
Other comprehensive (loss) income, net of tax	(1,018)				(1,018)
Ending balance at Sep. 30, 2016	$ 1,199,967	$ 5	$ 909,067	$ 286,578	$ (1,011)	$ 5,328
Ending balance, shares at Sep. 30, 2016		49,486,623