Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total Par Value Of Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance, period start at Jun. 30, 2017	$ 7,822	$ 26,186	$ 198,465	$ (1,713)	$ 230,760
Issuance of common stock:
Stock options exercised, net	5	71			76
Unrealized gain on available for sale investments, net of tax				(23)	(23)
Long-term incentive compensation	20	(298)			(278)
Stock-based compensation	8	628			636
Cash dividends declared			(5,181)		(5,181)
Net income			15,480		15,480
Balance, period end at Mar. 31, 2018	7,855	26,587	208,764	(1,736)	241,470
Balance, period start at Jun. 30, 2018	7,868	26,321	209,553	(2,044)	241,698
Issuance of common stock:
Stock options exercised, net	5	76			81
Unrealized gain on available for sale investments, net of tax				21	21
Long-term incentive compensation	7	(315)			(308)
Stock-based compensation	14	998			1,012
Terminated pension adjustment, net of tax				2,018	2,018
Cash dividends declared			(5,206)		(5,206)
Net income			(12,690)		(12,690)
Balance, period end at Mar. 31, 2019	$ 7,894	$ 27,080	$ 191,657	$ (5)	$ 226,626