Income Taxes - Reconciliation for Significant Differences in Tax at Statutory and Effective Rates (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal income tax expense	21.00%	35.00%	35.00%
State income tax expense, net of federal tax effect	9.70%	5.00%	(3.60%)
Effect of differences in U.S. and foreign statutory rates	2.00%	1.90%	(53.70%)
Uncertain tax positions	(0.80%)	0.00%	3.40%
Earn-out adjustments	0.00%	0.00%	0.00%
Provision to return	(40.60%)	(0.70%)	4.50%
Non-deductible expenses	(16.90%)	(48.00%)	8.90%
Other	(0.60%)	(0.20%)	0.60%
Foreign deemed dividend	0.00%	0.00%	262.20%
Foreign tax credit	(0.00%)	20.30%	(126.10%)
Undistributed foreign earnings	4.50%	57.30%	906.50%
Effect of change in federal statutory rate	0.00%	(23.00%)	0.00%
Valuation allowance	14.20%	(49.60%)	(960.90%)
Effective income tax rate	(7.50%)	(2.00%)	76.80%