Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock Voting	Additional Paid In Capital	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	(Accumulated Deficit) Retained Earnings
Beginning balance, common stock (in shares) at Mar. 31, 2023		128,683,824
Beginning balance at Mar. 31, 2023	$ 2,029,649	$ 128	$ 3,099,698	$ 5,738	$ (1,546,128)	$ 470,213
Beginning balance, treasury stock (in shares) at Mar. 31, 2023					57,434,779
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(4,200)					(4,200)
Unrealized net investment gains (losses)	(106)			(106)
Unrealized net gain (losses) on derivative financial instruments	103			103
Cumulative translation adjustments	68			68
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		1,332,217
Issuance of common stock pursuant to vesting of restricted stock units	2	$ 2
Stock-based compensation expense for restricted stock units granted to employees	19,100		19,100
Repurchase of treasury stock (in shares)					435,172
Repurchase of treasury stock	(13,406)				$ (13,406)
Ending balance, common stock (in shares) at Jun. 30, 2023		130,016,041
Ending balance at Jun. 30, 2023	$ 2,031,210	$ 130	3,118,798	5,803	$ (1,559,534)	466,013
Ending balance, treasury stock (in shares) at Jun. 30, 2023					57,869,951
Beginning balance, common stock (in shares) at Mar. 31, 2024	71,404,216	131,316,309
Beginning balance at Mar. 31, 2024	$ 1,892,065	$ 131	3,181,366	3,572	$ (1,615,483)	322,479
Beginning balance, treasury stock (in shares) at Mar. 31, 2024	59,912,093				59,912,093
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (443,376)					(443,376)
Unrealized net investment gains (losses)	7			7
Unrealized net gain (losses) on derivative financial instruments	(44)			(44)
Cumulative translation adjustments	(131)			(131)
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		1,872,919
Issuance of common stock pursuant to vesting of restricted stock units	2	$ 2
Stock-based compensation expense for restricted stock units granted to employees	20,632		20,632
Repurchase of treasury stock (in shares)					1,965,726
Repurchase of treasury stock	$ (37,159)				$ (37,159)
Ending balance, common stock (in shares) at Jun. 30, 2024	71,311,409	133,189,228
Ending balance at Jun. 30, 2024	$ 1,431,996	$ 133	$ 3,201,998	$ 3,404	$ (1,652,642)	$ (120,897)
Ending balance, treasury stock (in shares) at Jun. 30, 2024	61,877,819				61,877,819