Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock Voting	Additional Paid In Capital	Accumulated Other Comprehensive Income (Loss)	Treasury stock	Retained Earnings
Beginning balance, common stock (in shares) at Mar. 31, 2020		122,006,077
Beginning balance at Mar. 31, 2020	$ 1,937,919	$ 122	$ 2,891,553	$ (3,160)	$ (1,305,935)	$ 355,339
Beginning balance, treasury stock (in shares) at Mar. 31, 2020					49,785,171
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	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, common stock (in shares) at Mar. 31, 2021		124,197,974
Ending balance at Mar. 31, 2021	2,005,779	$ 124	2,955,400	(1,940)	$ (1,322,496)	374,691
Ending balance, treasury stock (in shares) at Mar. 31, 2021					50,446,359
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	35,874					35,874
Unrealized net investment gains (losses)	(29)			(29)
Unrealized net losses on derivative financial instruments	20			20
Cumulative translation adjustments	153			153
Recognition of actuarial net gains (losses) from pension and other post-retirement plan	1,937			1,937
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		1,728,994
Issuance of common stock pursuant to vesting of restricted stock units	2	$ 2
Stock-based compensation expense for restricted stock units granted to employees	53,421		53,421
Issuance of common stock under employee stock purchase plan (in shares)		498,415
Issuance of common stock under employee stock purchase plan	14,582		14,582
Repurchase of treasury stock (in shares)					1,876,731
Repurchase of treasury stock	$ (51,344)				$ (51,344)
Ending balance, common stock (in shares) at Mar. 31, 2022	74,102,293	126,425,383
Ending balance at Mar. 31, 2022	$ 2,060,395	$ 126	3,023,403	141	$ (1,373,840)	410,565
Ending balance, treasury stock (in shares) at Mar. 31, 2022	52,323,090				52,323,090
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 59,648					59,648
Unrealized net investment gains (losses)	42			42
Unrealized net losses on derivative financial instruments	66			66
Cumulative translation adjustments	(270)			(270)
Recognition of actuarial net gains (losses) from pension and other post-retirement plan	5,759			5,759
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		1,777,658
Issuance of common stock pursuant to vesting of restricted stock units	2	$ 2
Stock-based compensation expense for restricted stock units granted to employees	59,086		59,086
Issuance of common stock under employee stock purchase plan (in shares)		480,783
Issuance of common stock under employee stock purchase plan	14,353		14,353
Repurchase of treasury stock (in shares)					5,111,689
Repurchase of treasury stock	$ (169,432)		2,856		$ (172,288)
Ending balance, common stock (in shares) at Mar. 31, 2023	71,249,045	128,683,824
Ending balance at Mar. 31, 2023	$ 2,029,649	$ 128	$ 3,099,698	$ 5,738	$ (1,546,128)	$ 470,213
Ending balance, treasury stock (in shares) at Mar. 31, 2023	57,434,779				57,434,779