CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Adoption of ASC 842 Leases	Common Stock	Treasury Shares	Additional Paid-In Capital	Retained Earnings	Retained Earnings Adoption of ASC 842 Leases	Accumulated Other Comprehensive Loss
Balance at beginning of period at Mar. 31, 2019	$ 263,686	$ (400)	$ 158	$ (49,964)	$ 46,633	$ 277,588	$ (400)	$ (10,729)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	1,213				1,213
Stock activity under stock plans	(792)		1	(793)
Net income	15,204					15,204
Dividends declared	(2,041)					(2,041)
Other comprehensive income (loss), net of tax	(43)							(43)
Balance at end of period at Jun. 30, 2019	276,827		159	(50,757)	47,846	290,351		(10,772)
Balance at beginning of period at Mar. 31, 2019	$ 263,686	$ (400)	158	(49,964)	46,633	277,588	$ (400)	(10,729)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201602Member
Balance at end of period at Mar. 31, 2020	$ 276,741		159	(75,377)	48,327	315,078		(11,446)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	1,328				1,328
Stock activity under stock plans	(1,670)		1	(1,670)	(1)
Repurchase of common shares	(7,291)			(7,291)
Reissuance of treasury shares	3,647			3,131	516
Net income	11,960					11,960
Dividends declared	(1,984)				12	(1,996)
Other comprehensive income (loss), net of tax	1,279							1,279
Balance at end of period at Jun. 30, 2020	$ 284,010		$ 160	$ (81,207)	$ 50,182	$ 325,042		$ (10,167)