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 at Jun. 30, 2013	$ 7,107	$ 10,615	$ 134,606	$ (1,091)	$ 151,237
Issuance of common stock:
Stock options exercised, net	223	2,165			2,388
Unrealized gain on available for sale investments, net of tax				(398)	(398)
Long-term incentive compensation	41	724			765
Stock-based compensation		525			525
Excess tax benefit from stock-based payment arrangements		(1,357)			(1,357)
Minimum pension liability adjustment, net of tax				233	233
Cash dividends declared			(4,362)		(4,362)
Net income			14,990		14,990
Balance at Jun. 30, 2014	7,371	15,386	145,234	(1,256)	166,735
Issuance of common stock:
Stock options exercised, net	83	707			790
Unrealized gain on available for sale investments, net of tax				(147)	(147)
Long-term incentive compensation	26	1,310			1,336
Stock-based compensation		607			607
Excess tax benefit from stock-based payment arrangements		817			817
Minimum pension liability adjustment, net of tax				(333)	(333)
Cash dividends declared			(5,357)		(5,357)
Net income			22,299		22,299
Balance at Jun. 30, 2015	7,480	18,827	162,176	(1,736)	186,747
Issuance of common stock:
Stock options exercised, net	184	1,407			1,591
Unrealized gain on available for sale investments, net of tax				128	128
Long-term incentive compensation	27	858			885
Stock-based compensation	9	406			415
Excess tax benefit from stock-based payment arrangements		1,761			1,761
Minimum pension liability adjustment, net of tax				(620)	(620)
Cash dividends declared			(5,494)		(5,494)
Net income			24,237		24,237
Balance at Jun. 30, 2016	$ 7,700	$ 23,259	$ 180,919	$ (2,228)	$ 209,650