CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Mar. 31, 2020		27,999,000
Beginning balance at Mar. 31, 2020	$ 1,140,120	$ 280	$ 191,451	$ 973,948	$ (25,559)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)		1,000
Stock-based compensation	3,618		3,618
Shares issued upon vesting (in shares)		1,000
Exercise of stock options (in shares)		4,000
Exercise of stock options	247		247
Shares withheld for taxes	(90)		(90)
Net income	(7,973)			(7,973)
Total other comprehensive income	1,006				1,006
Ending balance (in shares) at Jun. 30, 2020		28,005,000
Ending balance at Jun. 30, 2020	1,136,928	$ 280	195,226	965,975	(24,553)
Beginning balance (in shares) at Mar. 31, 2020		27,999,000
Beginning balance at Mar. 31, 2020	1,140,120	$ 280	191,451	973,948	(25,559)
Increase (Decrease) in Stockholders' Equity
Net income	93,581
Total other comprehensive income	6,601
Ending balance (in shares) at Sep. 30, 2020		28,082,000
Ending balance at Sep. 30, 2020	1,242,964	$ 281	194,112	1,067,529	(18,958)
Beginning balance (in shares) at Jun. 30, 2020		28,005,000
Beginning balance at Jun. 30, 2020	1,136,928	$ 280	195,226	965,975	(24,553)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)		1,000
Stock-based compensation	4,019		4,019
Shares issued upon vesting (in shares)		60,000
Shares issued upon vesting	698	$ 1	697
Exercise of stock options (in shares)		16,000
Exercise of stock options	1,134		1,134
Shares withheld for taxes	(6,964)		(6,964)
Net income	101,554			101,554
Total other comprehensive income	5,595				5,595
Ending balance (in shares) at Sep. 30, 2020		28,082,000
Ending balance at Sep. 30, 2020	1,242,964	$ 281	194,112	1,067,529	(18,958)
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)		1,000
Stock-based compensation	5,469		5,469
Exercise of stock options (in shares)		1,000
Exercise of stock options	69		69
Shares withheld for taxes	(85)		(85)
Repurchases of common stock (in shares)		(249,000)
Repurchases of common stock	(82,166)	$ (2)		(82,164)
Net income	48,124			48,124
Total other comprehensive income	3,351				3,351
Ending balance (in shares) at Jun. 30, 2021		27,663,000
Ending balance at Jun. 30, 2021	1,418,987	$ 277	208,763	1,223,339	(13,392)
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
Repurchases of common stock (in shares)	(381,861)
Repurchases of common stock	$ (135,973)
Net income	150,187
Total other comprehensive income	1,847
Ending balance (in shares) at Sep. 30, 2021		27,567,000
Ending balance at Sep. 30, 2021	1,463,746	$ 276	206,770	1,271,596	(14,896)
Beginning balance (in shares) at Jun. 30, 2021		27,663,000
Beginning balance at Jun. 30, 2021	1,418,987	$ 277	208,763	1,223,339	(13,392)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation (in shares)		1,000
Stock-based compensation	6,288		6,288
Shares issued upon vesting (in shares)		36,000
Shares issued upon vesting	914		914
Shares withheld for taxes	(9,195)		(9,195)
Repurchases of common stock (in shares)		(133,000)
Repurchases of common stock	(53,807)	$ (1)		(53,806)
Net income	102,063			102,063
Total other comprehensive income	(1,504)				(1,504)
Ending balance (in shares) at Sep. 30, 2021		27,567,000
Ending balance at Sep. 30, 2021	$ 1,463,746	$ 276	$ 206,770	$ 1,271,596	$ (14,896)