CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Mar. 31, 2021		27,910,000
Beginning balance at Mar. 31, 2021	$ 1,444,225	$ 279	$ 203,310	$ 1,257,379	$ (16,743)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)		4,000
Stock-based compensation	26,780		26,780
Shares issued upon vesting (in shares)		83,000
Shares issued upon vesting	1,991	$ 1	1,990
Exercise of stock options (in shares)		29,000
Exercise of stock options	1,204	$ 0	1,204
Shares withheld for taxes	$ (22,459)		(22,459)
Repurchases of common stock (Note 10) (in shares)	(1,043,554)	(1,044,000)
Repurchases of common stock (Note 10)	$ (356,653)	$ (10)		(356,643)
Net income	451,949			451,949
Total other comprehensive loss	(8,212)				(8,212)
Ending balance (in shares) at Mar. 31, 2022		26,982,000
Ending balance at Mar. 31, 2022	1,538,825	$ 270	210,825	1,352,685	(24,955)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)		5,000
Stock-based compensation	26,858		26,858
Shares issued upon vesting (in shares)		53,000
Shares issued upon vesting	2,170	$ 0	2,170
Exercise of stock options (in shares)		64,000
Exercise of stock options	4,396		4,396
Shares withheld for taxes	$ (11,317)		(11,317)
Repurchases of common stock (Note 10) (in shares)	(928,262)	(928,000)
Repurchases of common stock (Note 10)	$ (297,372)	$ (8)		(297,364)
Excise taxes related to repurchases of common stock	(569)			(569)
Net income	516,822			516,822
Total other comprehensive loss	$ (14,080)				(14,080)
Ending balance (in shares) at Mar. 31, 2023	26,176,000	26,176,000
Ending balance at Mar. 31, 2023	$ 1,765,733	$ 262	232,932	1,571,574	(39,035)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)		2,000
Stock-based compensation	37,248		37,248
Shares issued upon vesting (in shares)		59,000
Shares issued upon vesting	2,444	$ 0	2,444
Exercise of stock options (in shares)		71,000
Exercise of stock options	4,786		4,786
Shares withheld for taxes	$ (32,261)		(32,261)
Repurchases of common stock (Note 10) (in shares)	(714,854)	(715,000)
Repurchases of common stock (Note 10)	$ (414,931)	$ (7)		(414,924)
Excise taxes related to repurchases of common stock	(3,416)			(3,416)
Net income	759,563			759,563
Total other comprehensive loss	$ (11,698)				(11,698)
Ending balance (in shares) at Mar. 31, 2024	25,593,000	25,593,000
Ending balance at Mar. 31, 2024	$ 2,107,468	$ 255	$ 245,149	$ 1,912,797	$ (50,733)