Income Taxes - Schedule of Difference of Income Tax Expense from the United States Federal Income Tax Rates (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amount
Tax expense at statutory rate	$ 3,192	$ 7,320	$ 11,415
State taxes, net	852	1,575	1,626
Permanent differences	244	433	2,060
Change in statutory rate	0	0	(3,741)
Equity-based compensation benefits	371	(126)	0
Post-employment benefits	345	0	0
Uncertain tax position	93	154	0
Valuation allowance on capital loss	213	0	0
Other	(123)	(69)	133
Income Tax Expense	$ 5,187	$ 9,287	$ 11,493
Percentage
Tax expense at statutory rate (as a percent)	21.00%	21.00%	35.00%
State taxes, net (as a percent)	5.60%	4.51%	4.98%
Permanent differences (as a percent)	1.61%	1.24%	6.31%
Change in statutory rate (as a percent)	0.00%	0.00%	(11.47%)
Equity-based compensation benefits (as a percent)	2.44%	(0.36%)	0.00%
Post-employment benefits (as a percent)	2.27%	0.00%	0.00%
Uncertain tax position (as a percent)	0.61%	0.44%	0.00%
Valuation allowance on capital loss (as a percent)	1.40%	0.00%	0.00%
Other (as a percent)	(0.80%)	(0.19%)	0.42%
Total percentage	34.13%	26.64%	35.24%