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, 2016		32,020,000
Beginning balance at Mar. 31, 2016	$ 967,471	$ 320	$ 161,259	$ 826,449	$ (20,557)
Increase (Decrease) in Stockholders' Equity
Stock compensation expense (in shares)		23,000
Stock compensation expense	6,175		6,175
Shares issued upon vesting (in shares)		166,000
Shares issued upon vesting	798	$ 2	796
Excess tax benefit from stock compensation	100		100
Shares withheld for taxes	$ (7,533)		(7,533)
Repurchases of common stock (in shares)	(222,471)	(222,000)
Repurchases of common stock	$ (12,572)	$ (2)		(12,570)
Net income	5,710			5,710
Total other comprehensive loss	(5,894)				(5,894)
Ending balance (in shares) at Mar. 31, 2017		31,987,000
Ending balance at Mar. 31, 2017	954,255	$ 320	160,797	819,589	(26,451)
Increase (Decrease) in Stockholders' Equity
Stock compensation expense (in shares)		15,000
Stock compensation expense	14,302		14,302
Shares issued upon vesting (in shares)		148,000
Shares issued upon vesting	765	$ 1	764
Shares withheld for taxes	$ (8,276)		(8,276)
Repurchases of common stock (in shares)	(1,702,653)	(1,703,000)
Repurchases of common stock	$ (149,687)	$ (17)		(149,670)
Net income	114,394			114,394
Total other comprehensive loss	13,468				13,468
Ending balance (in shares) at Mar. 31, 2018		30,447,000
Ending balance at Mar. 31, 2018	940,779	$ 304	167,587	785,871	(12,983)
Increase (Decrease) in Stockholders' Equity
Stock compensation expense (in shares)		10,000
Stock compensation expense	14,773		14,773
Shares issued upon vesting (in shares)		85,000
Shares issued upon vesting	1,025	$ 1	1,024
Shares withheld for taxes	$ (5,157)		(5,157)
Repurchases of common stock (in shares)	(1,400,699)	(1,401,000)
Repurchases of common stock	$ (161,395)	$ (14)		(161,381)
Net income	264,308			264,308
Total other comprehensive loss	(9,671)				(9,671)
Ending balance (in shares) at Mar. 31, 2019		29,141,000
Ending balance at Mar. 31, 2019	$ 1,045,130	$ 291	$ 178,227	$ 889,266	$ (22,654)