Consolidated Statements of Stockholders' (Deficit) Equity and Redeemable Instruments - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid In Capital [Member]	(Accumulated Deficit) / Retained Earnings [Member]	Treasury Stock [Member]	Redeemable Preferred Stock [Member]	Redeemable Common Stock [Member]
BALANCE at Dec. 31, 2013	$ (71,429)	$ 162		$ (71,591)
BALANCE, Shares at Dec. 31, 2013		16,183,901
Net income	13,932			13,932
Initial Public Offering (IPO), Value	78,949	$ 86	$ 78,863
Initial Public Offering (IPO), Shares		8,567,500
Secondary Public Offering, Value	14,292	$ 12	14,280
Secondary Public Offering, Shares		1,214,196
Termination of Redemption Feature Upon IPO, Value	89,367	$ 58	89,309
Termination of Redemption Feature Upon IPO, Shares		5,850,000
Accretion of Redeemable Preferred to Redemption Value	(19,897)		(19,897)
Adjustments to Redeemable Common Stock Fair Value Measurement	(8,357)		(8,357)
Share-Based Compensation issued to Directors, Value	300	$ 1	299
Share-Based Compensation issued to Directors, Shares		23,490
Common Stock Repurchase, Value	(5,283)				$ (5,283)
Common Stock Repurchase, Shares					(300,000)
BALANCE at Dec. 31, 2014	91,874	$ 319	154,497	(57,659)	$ (5,283)
BALANCE, Shares at Dec. 31, 2014		31,839,087
BALANCE, Treasury Shares at Dec. 31, 2014					(300,000)
BALANCE at Dec. 31, 2013						$ 55,838	$ 81,010
BALANCE, Shares at Dec. 31, 2013						1,000	5,850,000
Redemption of Redeemable Preferred Stock, Value						$ (75,735)
Redemption of Redeemable Preferred Stock, Shares						(1,000)
Termination of Redemption Feature Upon IPO, Value	(89,367)						$ (89,367)
Termination of Redemption Feature Upon IPO, Shares							(5,850,000)
Accretion of Redeemable Preferred to Redemption Value						$ 19,897
Adjustments to Redeemable Common Stock Fair Value Measurement	8,357						$ 8,357
BALANCE at Dec. 31, 2014							$ 0
BALANCE, Shares at Dec. 31, 2014						0
Net income	26,517			26,517
Issuance of Common Stock Awards to Employees, Value		$ 1	(1)
Issuance of Common Stock Awards to Employees, Shares		130,613
Surrender of Common Stock Awards by Employees, Shares					(1,560)
Share-Based Compensation Expense	1,816		1,816
Share-Based Compensation issued to Directors, Value	300		300
Share-Based Compensation issued to Directors, Shares		13,188
Tax Benefit from Stock Plan	76		76
Common Stock Repurchase, Value	(6,100)				$ (6,100)
Common Stock Repurchase, Shares					(315,000)
BALANCE at Dec. 31, 2015	$ 114,483	$ 320	156,688	(31,142)	$ (11,383)
BALANCE, Shares at Dec. 31, 2015	31,982,888	31,982,888
BALANCE, Treasury Shares at Dec. 31, 2015	(616,560)				(616,560)
Net income	$ 38,436			38,436
Issuance of Common Stock Awards to Employees, Value		$ 1	(1)
Issuance of Common Stock Awards to Employees, Shares		143,528
Surrender of Common Stock Awards by Employees, Value	(836)				$ (836)
Surrender of Common Stock Awards by Employees, Shares					(33,842)
Share-Based Compensation Expense	1,594		1,594
Share-Based Compensation issued to Directors, Value	300		300
Share-Based Compensation issued to Directors, Shares		8,760
BALANCE at Dec. 31, 2016	$ 153,977	$ 321	$ 158,581	$ 7,294	$ (12,219)
BALANCE, Shares at Dec. 31, 2016	32,135,176	32,135,176
BALANCE, Treasury Shares at Dec. 31, 2016	(650,402)				(650,402)