CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Common stock, shares, beginning of period at Mar. 31, 2018		33,251
Stockholders' equity, beginning of period at Mar. 31, 2018	$ 352,970	$ 816	$ 876,645	$ 2,870	$ 299,066	$ (826,427)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	14,471				14,471
Net unrealized gains (losses) on cash flow hedges, net of tax	3,839			3,839
Proceeds from issuances under stock-based compensation plans, shares		361
Proceeds from issuances under stock-based compensation plans	10,558	$ 3	10,555
Repurchase of restricted common stock, shares		(53)
Cash dividends	(5,014)				(5,014)
Stock-based compensation	8,150		8,150
Employees' tax withheld and paid for restricted stock and restricted stock units, shares		(187)
Employees' tax withheld and paid for restricted stock and restricted stock units	(13,035)					(13,035)
Common stock, shares, end of period at Jun. 30, 2018		33,372
Stockholders' equity, end of period at Jun. 30, 2018	374,533	$ 819	895,350	6,585	311,241	(839,462)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Impact of new accounting standards adoption	(89)				(89)
Common stock, shares, beginning of period at Mar. 31, 2019		39,518
Stockholders' equity, beginning of period at Mar. 31, 2019	721,687	$ 884	1,431,608	(475)	143,344	(853,674)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(44,871)				(44,871)
Foreign currency translation adjustments	(219)			(219)
Net unrealized gains (losses) on cash flow hedges, net of tax	(5,934)			(5,934)
Proceeds from issuances under stock-based compensation plans, shares		271
Proceeds from issuances under stock-based compensation plans	589	$ 3	586
Repurchase of restricted common stock, shares		(20)
Cash dividends	(5,940)				(5,940)
Stock-based compensation	12,904		12,904
Employees' tax withheld and paid for restricted stock and restricted stock units, shares		191
Employees' tax withheld and paid for restricted stock and restricted stock units	(8,622)					(8,622)
Other equity changes	(7)				(7)	0
Common stock, shares, end of period at Jun. 30, 2019		39,578
Stockholders' equity, end of period at Jun. 30, 2019	$ 669,498	$ 887	$ 1,445,098	$ (6,628)	$ 92,437	$ (862,296)