CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in Capital	Retained earnings	Accumulated other comprehensive income (loss)	Treasury Stock
Balance, beginning of the period (in shares) at Mar. 31, 2019		141,865,888				(73,167,892)
Balance, beginning of the period at Mar. 31, 2019	$ 1,330,832	$ 14,187	$ 1,406,813	$ 1,669,605	$ 7,801	$ (1,767,574)
Increase (Decrease) in Stockholders' Equity
Employee stock awards, benefit plans and other issuances (in shares)		194,743				(350,847)
Employee stock awards, benefit plans and other issuances	(14,652)	$ 19	3,386			$ (18,057)
Non-cash stock-based compensation (in shares)		64,130
Non-cash stock-based compensation	48,952	$ 7	48,945
Restricted stock units vested (in shares)		884,235
Restricted stock units vested	0	$ 88	(88)
Liability-classified restricted stock units vested (in shares)		418,850
Liability-classified restricted stock units vested	17,704	$ 42	17,662
Acquisition-related replacement stock options	2,300		2,300
Acquisition of treasury stock (in shares)						(2,558,883)
Acquisition of treasury stock	(121,188)					$ (121,188)
Other comprehensive income (loss):
Foreign currency translation	(1,025)				(1,025)
Net loss	(120,382)			(120,382)
Balance, end of the period (in shares) at Dec. 31, 2019		143,427,846				(76,077,622)
Balance, end of the period at Dec. 31, 2019	1,142,541	$ 14,343	1,479,018	1,549,223	6,776	$ (1,906,819)
Balance, beginning of the period (in shares) at Sep. 30, 2019		143,096,272				(75,558,291)
Balance, beginning of the period at Sep. 30, 2019	1,186,358	$ 14,310	1,460,120	1,587,263	6,619	$ (1,881,954)
Increase (Decrease) in Stockholders' Equity
Employee stock awards, benefit plans and other issuances (in shares)		75,557				(95,378)
Employee stock awards, benefit plans and other issuances	(2,839)	$ 7	1,304			$ (4,150)
Non-cash stock-based compensation (in shares)		5,935
Non-cash stock-based compensation	17,620	$ 1	17,619
Restricted stock units vested (in shares)		250,082
Restricted stock units vested	0	$ 25	(25)
Acquisition of treasury stock (in shares)						(423,953)
Acquisition of treasury stock	(20,715)					$ (20,715)
Other comprehensive income (loss):
Foreign currency translation	157				157
Net loss	(38,040)			(38,040)
Balance, end of the period (in shares) at Dec. 31, 2019		143,427,846				(76,077,622)
Balance, end of the period at Dec. 31, 2019	1,142,541	$ 14,343	1,479,018	1,549,223	6,776	$ (1,906,819)
Balance, beginning of the period (in shares) at Mar. 31, 2020		143,938,753				(78,081,314)
Balance, beginning of the period at Mar. 31, 2020	1,087,512	$ 14,394	1,496,565	1,545,094	5,745	$ (1,974,286)
Increase (Decrease) in Stockholders' Equity
Employee stock awards, benefit plans and other issuances (in shares)		566,704				(174,622)
Employee stock awards, benefit plans and other issuances	(705)	$ 56	8,621			$ (9,382)
Non-cash stock-based compensation (in shares)		17,548
Non-cash stock-based compensation	44,917	$ 2	44,915
Restricted stock units vested (in shares)		1,169,530
Restricted stock units vested	0	$ 117	(117)
Liability-classified restricted stock units vested (in shares)		780,400
Liability-classified restricted stock units vested	24,441	$ 78	24,363
Acquisition of treasury stock (in shares)						(1,321,666)
Acquisition of treasury stock	(42,312)					$ (42,312)
Other comprehensive income (loss):
Foreign currency translation	2,069				2,069
Net loss	(57,421)			(57,421)
Balance, end of the period (in shares) at Dec. 31, 2020		146,472,935				(79,577,602)
Balance, end of the period at Dec. 31, 2020	1,058,501	$ 14,647	1,574,347	1,487,673	7,814	$ (2,025,980)
Balance, beginning of the period (in shares) at Sep. 30, 2020		145,705,138				(79,516,592)
Balance, beginning of the period at Sep. 30, 2020	1,050,862	$ 14,570	1,552,303	1,499,398	6,944	$ (2,022,353)
Increase (Decrease) in Stockholders' Equity
Employee stock awards, benefit plans and other issuances (in shares)		371,888				(61,010)
Employee stock awards, benefit plans and other issuances	1,489	$ 37	5,079			$ (3,627)
Non-cash stock-based compensation (in shares)		3,997
Non-cash stock-based compensation	17,005	$ 1	17,004
Restricted stock units vested (in shares)		391,912
Restricted stock units vested	0	$ 39	(39)
Other comprehensive income (loss):
Foreign currency translation	870				870
Net loss	(11,725)			(11,725)
Balance, end of the period (in shares) at Dec. 31, 2020		146,472,935				(79,577,602)
Balance, end of the period at Dec. 31, 2020	$ 1,058,501	$ 14,647	$ 1,574,347	$ 1,487,673	$ 7,814	$ (2,025,980)