Condensed Consolidated Statements of Equity (Unaudited) - 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, 2019	$ 1,916,078	$ 6	$ 1,656,819	$ 245,585	$ 5,338	$ 8,330
Beginning balance, shares at Mar. 31, 2019		60,550,093
Exercise of stock options	20,743		20,743
Exercise of stock options, shares		335,373
Issuance of stock under Employee Stock Purchase Plan	17,350		17,350
Issuance of stock under Employee Stock Purchase Plan, shares		311,137
Stock-based compensation	73,523		73,523
Shares issued in settlement of certain accrued employee compensation liabilities	22,829		22,829
Shares issued in settlement of certain accrued employee compensation liabilities, shares		255,615
RSU awards vesting, net of shares withheld for taxes which have been retired	(28,268)		(28,268)
RSU awards vesting, net of shares withheld for taxes which have been retired, shares		671,040
Net (loss) income	8,915			(1,798)		10,713
Other comprehensive income (loss), net of tax	(5,859)				(5,859)
Ending balance at Dec. 31, 2019	2,025,311	$ 6	1,762,996	243,787	(521)	19,043
Ending balance, shares at Dec. 31, 2019		62,123,258
Beginning balance at Sep. 30, 2019	2,005,836	$ 6	1,751,924	237,311	1,666	14,929
Beginning balance, shares at Sep. 30, 2019		61,352,560
Exercise of stock options	2,033		2,033
Exercise of stock options, shares		33,642
Issuance of stock under Employee Stock Purchase Plan	9,044		9,044
Issuance of stock under Employee Stock Purchase Plan, shares		145,367
Stock-based compensation	25,135		25,135
RSU awards vesting, net of shares withheld for taxes which have been retired	(25,140)		(25,140)
RSU awards vesting, net of shares withheld for taxes which have been retired, shares		591,689
Net (loss) income	10,590			6,476		4,114
Other comprehensive income (loss), net of tax	(2,187)				(2,187)
Ending balance at Dec. 31, 2019	2,025,311	$ 6	1,762,996	243,787	(521)	19,043
Ending balance, shares at Dec. 31, 2019		62,123,258
Beginning balance at Mar. 31, 2020	2,050,142	$ 6	1,788,456	245,373	(6,048)	22,355
Beginning balance, shares at Mar. 31, 2020		62,147,140
Issuance of stock under Employee Stock Purchase Plan	19,101		19,101
Issuance of stock under Employee Stock Purchase Plan, shares		638,792
Common stock issued in private placement, net of issuance costs	174,749	$ 1	174,748
Common stock issued in private placement, net of issuance costs, shares		4,474,559
Stock-based compensation	75,655		75,655
Shares issued in settlement of certain accrued employee compensation liabilities	25,406		25,406
Shares issued in settlement of certain accrued employee compensation liabilities, shares		580,846
RSU awards vesting, net of shares withheld for taxes which have been retired	(13,013)		(13,013)
RSU awards vesting, net of shares withheld for taxes which have been retired, shares		662,991
Net (loss) income	2,624			(3,666)		6,290
Other comprehensive income (loss), net of tax	12,662				12,662
Ending balance at Dec. 31, 2020	2,347,326	$ 7	2,070,353	241,707	6,614	28,645
Ending balance, shares at Dec. 31, 2020		68,504,328
Beginning balance at Sep. 30, 2020	2,307,691	$ 7	2,047,525	234,947	(2,433)	27,645
Beginning balance, shares at Sep. 30, 2020		67,532,869
Issuance of stock under Employee Stock Purchase Plan	9,895		9,895
Issuance of stock under Employee Stock Purchase Plan, shares		356,523
Stock-based compensation	25,199		25,199
RSU awards vesting, net of shares withheld for taxes which have been retired	(12,266)		(12,266)
RSU awards vesting, net of shares withheld for taxes which have been retired, shares		614,936
Net (loss) income	7,760			6,760		1,000
Other comprehensive income (loss), net of tax	9,047				9,047
Ending balance at Dec. 31, 2020	$ 2,347,326	$ 7	$ 2,070,353	$ 241,707	$ 6,614	$ 28,645
Ending balance, shares at Dec. 31, 2020		68,504,328