Income Taxes - Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Allowance for uncollectible accounts	$ 8,645	$ 5,224
Accrued employee benefits	6,038	4,147
Stock compensation	2,322	663
Accrued self-insurance	8,656	2,157
Acquisition costs	1,413	2,064
Net operating loss carry forward	9,147	1,299
Intangible asset impairment	18	21
Other	1,021	91
Capital loss carryforward	0	12
Valuation allowance	(3,574)	(44)
Deferred tax assets	33,686	15,634
Deferred tax liabilities:
Amortization of intangible assets	(64,001)	(35,955)
Tax depreciation in excess of book depreciation	(7,693)	(5,988)
Prepaid expenses	(1,134)	(623)
Non-accrual experience accounting method	(602)	(534)
Other	(3,562)	0
Deferred tax liabilities	(76,992)	(43,100)
Net deferred tax liability	$ (43,306)	$ (27,466)