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 2016-01 [Member]	[1]			$ 114	$ (114)	[2]		$ 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 net of taxes					398			398
Balance at Mar. 31, 2019		861	11,017	98,003	(1,339)		(277)	108,265
Balance at Dec. 31, 2018		861	11,017	94,040	(1,520)		(277)	104,121
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared				(393)				(393)
Net income				4,356				4,356
Other comprehensive income net of taxes					181			181
Balance at Mar. 31, 2019		861	11,017	98,003	(1,339)		(277)	108,265
Balance at Jun. 30, 2019		861	11,017	101,774	(1,006)		(277)	112,369
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock repurchases							(631)	(631)
Dividends declared				(1,808)				(1,808)
Net income				14,027				14,027
Other comprehensive income net of taxes					36			36
Balance at Mar. 31, 2020		861	11,017	113,993	(970)		(908)	123,993
Balance at Dec. 31, 2019		861	11,017	110,374	(1,391)		(315)	120,546
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock repurchases							(594)	(594)
Dividends declared				(432)				(432)
Net income				4,051				4,051
Other comprehensive income net of taxes					421			421
Balance at Mar. 31, 2020		$ 861	$ 11,017	$ 113,993	$ (970)		$ (908)	$ 123,993

[1] Cumulative effect of change in measurement of equity securities (ASU 2016-01).

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