Unaudited Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2017	$ 73	$ 6,987	$ 62,115	$ 69,175
Balance (in shares) at Dec. 31, 2017	7,287,500
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	0	6,349	6,349
Balance at Mar. 31, 2018	$ 73	6,987	68,464	75,524
Balance (in shares) at Mar. 31, 2018	7,287,500
Balance at Dec. 31, 2018	$ 102	80,275	8,089	88,466
Balance (in shares) at Dec. 31, 2018	10,187,500
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	0	5,116	5,116
Stock-based compensation expense	0	171	0	171
Balance at Mar. 31, 2019	$ 102	$ 80,446	$ 13,205	$ 93,753
Balance (in shares) at Mar. 31, 2019	10,187,500