CONDENSED CONSOLIDATED STATEMENT 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, 2018		136,079,676				(58,304,917)
Balance, beginning of the period at Mar. 31, 2018	$ 749,095	$ 13,609	$ 1,235,679	$ 628,331	$ 10,767	$ (1,139,291)
Increase (Decrease) in Stockholders' Equity
Employee stock awards, benefit plans and other issuances (in shares)		233,784				(391,898)
Employee stock awards, benefit plans and other issuances	(5,928)	$ 23	4,093			$ (10,044)
Non-cash stock-based compensation (in shares)		149,416
Non-cash stock-based compensation	16,811	$ 15	16,796
Restricted stock units vested (in shares)		1,259,681
Restricted stock units vested	0	$ 126	(126)
Acquisition of treasury stock (in shares)						(1,853,071)
Acquisition of treasury stock	(45,766)					$ (45,766)
Other comprehensive income (loss):
Foreign currency translation	(1,868)				(1,868)
Net earnings (loss)	(3,015)			(3,015)
Balance, end of the period (in shares) at Jun. 30, 2018		137,722,557				(60,549,886)
Balance, end of the period at Jun. 30, 2018	722,056	$ 13,773	1,256,442	638,043	8,899	$ (1,195,101)
Balance, beginning of the period (in shares) at Mar. 31, 2018		136,079,676				(58,304,917)
Balance, beginning of the period at Mar. 31, 2018	749,095	$ 13,609	1,235,679	628,331	10,767	$ (1,139,291)
Increase (Decrease) in Stockholders' Equity
Non-cash stock-based compensation	34,100
Other comprehensive income (loss):
Foreign currency translation	(575)
Net earnings (loss)	17,608
Balance, end of the period (in shares) at Sep. 30, 2018		138,356,148				(60,650,555)
Balance, end of the period at Sep. 30, 2018	760,678	$ 13,836	1,277,614	658,666	10,192	$ (1,199,630)
Balance, beginning of the period (in shares) at Jun. 30, 2018		137,722,557				(60,549,886)
Balance, beginning of the period at Jun. 30, 2018	722,056	$ 13,773	1,256,442	638,043	8,899	$ (1,195,101)
Increase (Decrease) in Stockholders' Equity
Employee stock awards, benefit plans and other issuances (in shares)		205,553				(104,157)
Employee stock awards, benefit plans and other issuances	(575)	$ 21	3,984			$ (4,580)
Non-cash stock-based compensation (in shares)		91,168
Non-cash stock-based compensation	17,281	$ 9	17,272
Restricted stock units vested (in shares)		336,870
Restricted stock units vested	0	$ 33	(33)
Other comprehensive income (loss):
Foreign currency translation	1,293				1,293
Net earnings (loss)	20,623			20,623
Warrant exercises			(51)			$ 51
Warrant exercises (in shares)						3,488
Balance, end of the period (in shares) at Sep. 30, 2018		138,356,148				(60,650,555)
Balance, end of the period at Sep. 30, 2018	760,678	$ 13,836	1,277,614	658,666	10,192	$ (1,199,630)
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)		46,681				(221,195)
Employee stock awards, benefit plans and other issuances	(11,033)	$ 4	1,056			$ (12,093)
Non-cash stock-based compensation (in shares)		51,362
Non-cash stock-based compensation	15,064	$ 5	15,059
Restricted stock units vested (in shares)		487,632
Restricted stock units vested	0	$ 49	(49)
Acquisition of treasury stock (in shares)						(412,200)
Acquisition of treasury stock	(20,099)					$ (20,099)
Other comprehensive income (loss):
Foreign currency translation	(467)				(467)
Net earnings (loss)	(42,140)			(42,140)
Balance, end of the period (in shares) at Jun. 30, 2019		142,451,563				(73,801,287)
Balance, end of the period at Jun. 30, 2019	1,272,157	$ 14,245	1,422,879	1,627,465	7,334	$ (1,799,766)
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
Non-cash stock-based compensation	31,300
Other comprehensive income (loss):
Foreign currency translation	(1,182)
Net earnings (loss)	(82,342)
Balance, end of the period (in shares) at Sep. 30, 2019		143,096,272				(75,558,291)
Balance, end of the period at Sep. 30, 2019	1,186,358	$ 14,310	1,460,120	1,587,263	6,619	$ (1,881,954)
Balance, beginning of the period (in shares) at Jun. 30, 2019		142,451,563				(73,801,287)
Balance, beginning of the period at Jun. 30, 2019	1,272,157	$ 14,245	1,422,879	1,627,465	7,334	$ (1,799,766)
Increase (Decrease) in Stockholders' Equity
Employee stock awards, benefit plans and other issuances (in shares)		72,505				(34,274)
Employee stock awards, benefit plans and other issuances	(780)	$ 8	1,026			$ (1,814)
Non-cash stock-based compensation (in shares)		6,833
Non-cash stock-based compensation	16,268	$ 1	16,267
Restricted stock units vested (in shares)		146,521
Restricted stock units vested	0	$ 14	(14)
Acquisition of treasury stock (in shares)						(1,722,730)
Acquisition of treasury stock	(80,374)					$ (80,374)
Other comprehensive income (loss):
Foreign currency translation	(715)				(715)
Net earnings (loss)	(40,202)			(40,202)
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
Balance, end of the period (in shares) at Sep. 30, 2019		143,096,272				(75,558,291)
Balance, end of the period at Sep. 30, 2019	$ 1,186,358	$ 14,310	$ 1,460,120	$ 1,587,263	$ 6,619	$ (1,881,954)