Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Beginning balance at Dec. 31, 2017	$ 212,705	$ 196	$ (26,096)	$ 226,006	$ (716)	$ 13,315
Beginning balance, shares at Dec. 31, 2017		19,586,000	805,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	10,168				10,168
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	8,954
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | Accounting Standards Update 2014-09 [Member]					15,043
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | Accounting Standards Update 2016-01 [Member]						(6,089)
Other comprehensive income, net of tax	1,590					1,590
Common and treasury stock transactions:
Stock-based compensation	1,776			1,776
Vesting of equity, net of tax withholdings	2,233		$ (4,614)	6,847
Vesting of equity, net of tax withholdings, shares			138,000
Cash dividends declared ($0.13 per share)	(2,460)				2,460
Dividend equivalents on restricted stock units	11				11
Ending balance at Mar. 31, 2018	230,489	$ 196	$ (21,482)	220,935	22,024	8,816
Ending balance, shares at Mar. 31, 2018		19,586,000	667,000
Beginning balance at Dec. 31, 2018	$ 267,156	$ 196	$ (20,298)	227,147	56,049	4,062
Beginning balance, shares at Dec. 31, 2018	18,954,275	19,586,000	632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 12,087				12,087
Other comprehensive income, net of tax	320					320
Common and treasury stock transactions:
Stock-based compensation	1,343			1,343
Vesting of equity, net of tax withholdings	4,552		$ (5,155)	9,707
Vesting of equity, net of tax withholdings, shares			160,000
Cash dividends declared ($0.13 per share)	(2,848)				2,848
Dividend equivalents on restricted stock units	87				87
Ending balance at Mar. 31, 2019	$ 273,419	$ 196	$ (15,143)	$ 218,783	$ 65,201	$ 4,382
Ending balance, shares at Mar. 31, 2019	19,113,630	19,586,000	472,000