Condensed Consolidated Statement of Equity (Unaudited) - 9 months ended Dec. 31, 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	12,117		12,117
Exercise of stock options, shares		273,050
Issuance of stock under Employee Stock Purchase Plan	10,286		10,286
Issuance of stock under Employee Stock Purchase Plan, shares		188,938
Common stock issued in public offering, net of issuance costs	503,061	$ 1	503,060
Common stock issued in public offering, net of issuance costs, shares		7,475,000
Stock-based compensation	44,807		44,807
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	(21,150)		(21,150)
RSU awards vesting, net of shares withheld for taxes which have been retired, shares		487,006
Shares issued in connection with acquisition of business	4,988		4,988
Shares issued in connection with acquisition of business, shares		61,888
Other noncontrolling interest activity	(16)					(16)
Net income	17,518			17,117		401
Other comprehensive loss, net of tax	(2,473)				(2,473)
Ending balance at Dec. 31, 2016	$ 1,716,642	$ 6	$ 1,422,575	$ 290,821	$ (2,466)	$ 5,706
Ending balance, shares at Dec. 31, 2016		57,589,030