Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common stock Voting	Additional Paid In Capital	Accumulated Other Comprehensive Income (Loss)	Treasury stock	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment
Beginning balance (in shares) at Mar. 31, 2018			117,744,913			(37,474,890)
Beginning balance at Mar. 31, 2018	$ 2,068,782	$ 34,924	$ 117	$ 2,665,120	$ 2,895	$ (995,843)	$ 396,493	$ 34,924
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(73,324)						(73,324)
Unrealized net investment gains (losses)	60				60
Unrealized net losses on derivative financial instruments	(87)				(87)
Cumulative translation adjustments	(3,229)				(3,229)
Recognition of actuarial net gains (losses) from pension and other post-retirement plan	(2,278)				(2,278)
Issuance of common stock pursuant to vesting of restricted stock units (in shares)			1,438,219
Issuance of common stock pursuant to vesting of restricted stock units	3		$ 3
Stock-based compensation expense for restricted stock units granted to employees	51,945			51,945
Issuance of common stock under employee stock purchase plan (in shares)			577,000
Issuance of common stock under employee stock purchase plan	15,074			15,074
Repurchase of treasury stock (in shares)						4,674,881
Repurchase of treasury stock	(26,437)			96,783		$ (123,220)
Ending balance (in shares) at Mar. 31, 2019			119,760,132			(42,149,771)
Ending balance at Mar. 31, 2019	2,065,433		$ 120	2,828,922	(2,639)	$ (1,119,063)	358,093
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(2,754)						(2,754)
Unrealized net investment gains (losses)	126				126
Unrealized net losses on derivative financial instruments	(57)				(57)
Cumulative translation adjustments	(1,644)				(1,644)
Recognition of actuarial net gains (losses) from pension and other post-retirement plan	1,054				1,054
Issuance of common stock pursuant to vesting of restricted stock units (in shares)			1,651,284
Issuance of common stock pursuant to vesting of restricted stock units	2		$ 2
Stock-based compensation expense for restricted stock units granted to employees	48,404			48,404
Issuance of common stock under employee stock purchase plan (in shares)			594,661
Issuance of common stock under employee stock purchase plan	14,227			14,227
Repurchase of treasury stock (in shares)						7,635,400
Repurchase of treasury stock	(186,872)					$ (186,872)
Ending balance (in shares) at Mar. 31, 2020			122,006,077			(49,785,171)
Ending balance at Mar. 31, 2020	1,937,919		$ 122	2,891,553	(3,160)	$ (1,305,935)	355,339
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	19,352						19,352
Unrealized net investment gains (losses)	(130)				(130)
Unrealized net losses on derivative financial instruments	(28)				(28)
Cumulative translation adjustments	2,926				2,926
Recognition of actuarial net gains (losses) from pension and other post-retirement plan	(1,548)				(1,548)
Issuance of common stock pursuant to vesting of restricted stock units (in shares)			1,630,228
Issuance of common stock pursuant to vesting of restricted stock units	2		$ 2
Stock-based compensation expense for restricted stock units granted to employees	49,418			49,418
Issuance of common stock under employee stock purchase plan (in shares)			561,669
Issuance of common stock under employee stock purchase plan	14,429			14,429
Repurchase of treasury stock (in shares)						661,188
Repurchase of treasury stock	(16,561)					$ (16,561)
Ending balance (in shares) at Mar. 31, 2021			124,197,974			(50,446,359)
Ending balance at Mar. 31, 2021	$ 2,005,779		$ 124	$ 2,955,400	$ (1,940)	$ (1,322,496)	$ 374,691