CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) - 9 months ended Sep. 30, 2017 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
BALANCE at Dec. 31, 2016	$ 94,524	$ 30	$ 54,057	$ (8,329)	$ 48,799	$ (33)
BALANCE (in Shares) at Dec. 31, 2016	30,203	30,203
Net income	$ 46,946	$ 0	0	0	46,946	0
Share-based compensation expense	7,899	$ 0	7,899	0	0	0
Share-based compensation expense (in Shares)		178
Exercise of stock options	4,144	$ 0	4,144	0	0	0
Exercise of stock options (in Shares)		261
Purchase and retirement of common shares	(2,285)	$ 0	0	0	(2,285)	0
Purchase and retirement of common shares (in Shares)		(51)
Cash dividends	(15,987)	$ 0	0	0	(15,987)	0
Employee tax withholdings related to the vesting of equity awards	(1,596)	0	0	(1,596)	0	0
Other comprehensive income, net of tax	4	0	0	0	0	4
BALANCE at Sep. 30, 2017	$ 133,649	$ 30	$ 66,100	$ (9,925)	$ 77,473	$ (29)
BALANCE (in Shares) at Sep. 30, 2017	30,591	30,591