Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands		Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]		Treasury Stock [Member]	Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Impact of Adopting ASU | ASU 2018-02 [Member]	[1]			$ 259	$ (259)			$ 0
Balance at Jun. 30, 2017		$ 861	$ 10,990	73,072	(992)		$ (410)	83,521
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Options exercised			60				90	150
Dividends declared				(1,145)				(1,145)
Net income				10,789				10,789
Other comprehensive income (loss), net of taxes					(648)			(648)
Balance at Mar. 31, 2018		861	11,050	82,975	(1,899)		(320)	92,667
Balance at Dec. 31, 2017					(1,314)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income								3,677
Other comprehensive income (loss), net of taxes					(326)			(326)
Balance at Mar. 31, 2018		861	11,050	82,975	(1,899)		(320)	92,667
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Impact of Adopting ASU | ASU 2016-01 [Member]	[2]			114	(114)	[3]		0
Balance at Jun. 30, 2018		861	11,017	86,213	(1,623)		(277)	96,191
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared				(1,644)				(1,644)
Net income				13,320				13,320
Other comprehensive income (loss), net of taxes					398			398
Balance at Mar. 31, 2019		861	11,017	98,003	(1,339)		(277)	108,265
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Impact of Adopting ASU | ASU 2016-01 [Member]	[3]				0
Balance at Dec. 31, 2018					(1,520)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income								4,356
Other comprehensive income (loss), net of taxes					181			181
Balance at Mar. 31, 2019		$ 861	$ 11,017	$ 98,003	$ (1,339)		$ (277)	$ 108,265

[1] Adoption of Accounting Standard Update 2018-02, reclassification from accumulated other comprehensive loss to retained earnings for stranded tax effects resulting from newly enacted Federal corporate income tax rate from 34% to 21%.

[2] See Note 9 Impact of Recent Accounting Pronouncements - cumulative effect of change in measurement of equity securities.

[3] Adoption of ASU 2016-01 - cumulative effect of change in measurement of equity securities.