Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets (liabilities):
Net operating loss and other carryforwards	$ 324	$ 495
Credit carryforwards	2,878	3,237
Allowance for doubtful accounts	4,570	3,626
Prepaid expenses	(1,022)	(731)
Interest rate limitation	148	0
Deferred lease costs	0	32
Depreciation	1,318	1,190
Tax goodwill and intangibles	(1,079)	(972)
Stock-based compensation	197	476
Accrued liabilities	896	773
Accrued rent	1,914	1,892
Kentucky and Kansas acquisition costs	3	4
Impairment of long-lived assets	191	186
Interest rate swap	(152)	(14)
Hedge Ineffectiveness	(168)	(106)
Noncurrent self-insurance liabilities	5,997	5,443
Other	64	0
Subtotal	16,079	15,531
Less valuation allowance	(228)	(377)
Total noncurrent deferred tax assets	$ 15,851	$ 15,154