Unaudited Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital.	Retained Earnings	Total
Balance at Dec. 31, 2017	$ 396	$ 148,293	$ (35,292)	$ 113,397
Equity-based compensation	5	546		551
Net income			5,266	5,266
Balance at Mar. 31, 2018	401	148,839	(30,026)	119,214
Balance at Dec. 31, 2017	396	148,293	(35,292)	113,397
Net income				21,681
Balance at Sep. 30, 2018	401	150,228	(13,611)	137,018
Balance at Mar. 31, 2018	401	148,839	(30,026)	119,214
Equity-based compensation		694		694
Net income			10,204	10,204
Balance at Jun. 30, 2018	401	149,533	(19,822)	130,112
Equity-based compensation		695		695
Net income			6,211	6,211
Balance at Sep. 30, 2018	401	150,228	(13,611)	137,018
Balance at Dec. 31, 2018	401	150,926	(10,218)	141,109
Equity-based compensation	7	887		894
Net income			6,883	6,883
Balance at Mar. 31, 2019	408	151,813	(3,335)	148,886
Balance at Dec. 31, 2018	401	150,926	(10,218)	141,109
Net income				23,046
Balance at Sep. 30, 2019	409	153,976	12,828	167,213
Balance at Mar. 31, 2019	408	151,813	(3,335)	148,886
Equity-based compensation	1	1,059		1,060
Net income			10,613	10,613
Balance at Jun. 30, 2019	409	152,872	7,278	160,559
Equity-based compensation		1,104		1,104
Net income			5,550	5,550
Balance at Sep. 30, 2019	$ 409	$ 153,976	$ 12,828	$ 167,213