CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - 6 months ended Jun. 30, 2018 - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid- In Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance (Scenario, Previously Reported [Member]) at Dec. 31, 2017	$ 12	$ 4,967	$ (160)	$ 101,744		$ 106,563
Balance (Restatement Adjustment [Member])				(2,018)		(2,018)
Balance at Dec. 31, 2017	$ 12	4,967	(160)	103,762		108,581
Balance (in shares) (Scenario, Previously Reported [Member]) at Dec. 31, 2017	12,103
Balance (in shares) at Dec. 31, 2017	12,103
Net income				26,355		26,355
Share-based compensation		1,635				1,635
Share-based compensation (in shares)	16
Options exercised by executives and directors		62				62
Options exercised by executives and directors (in shares)	16
Net shares repurchased for employee taxes		(215)				(215)
Net shares repurchased for eimployee taxes, (in shares)	(3)
Treasury stock from cashless options	$ 9	750			$ (750)
Treasury stock from stock repurchases					(19,996)	(19,996)
Other comprehensive income (loss)			(59)			(59)
Cash dividends declared to stockholders				(11,482)		(11,482)
Balance at Jun. 30, 2018	$ 12	$ 7,199	$ (219)	$ 116,617	$ (20,746)	$ 102,863
Balance (in shares) at Jun. 30, 2018	12,141