Income Taxes - Tax Effects of Temporary Differences That Rises to Significant Portions of Deferred Tax Assets and Deferred Tax Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 1,229	$ 884
Allowance for doubtful accounts	3,022	4,486
Employee benefits and compensation	21,155	29,166
Lease costs	3,611	2,772
State tax credit carryforwards	1,385	1,489
Other deferred tax assets	1,161	2,951
Total gross deferred tax assets	31,563	41,748
Less: valuation allowance	(1,657)	(1,314)
Total deferred tax assets, net	29,906	40,434
Accrued interest	819	2,494
Client list intangible assets	1,513	2,717
Goodwill and other intangibles	30,913	38,646
Other deferred tax liabilities		122
Total gross deferred tax liabilities	33,245	43,979
Net deferred tax liability	$ (3,339)	$ (3,545)