Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Reconciliation [Line Items]
Net tax provision		$ 6,007,000	$ 13,152,000	$ 5,698,000
Cash taxes paid net of refunds		$ 5,600,000	$ 3,400,000	$ 6,900,000
Tax Cuts and Jobs Act incomplete accouning transition tax unrepatriated earnings foreign subsidiaries payable period		8 years
U.S. federal statutory tax rate		21.00%	35.00%	35.00%
Decrease in tax expense related to reduction of deferred tax assets and liabilities	$ 700,000
Decrease in tax expense related to Transition Tax	900,000
Net operating loss carryforwards, indefinite	7,700,000	$ 7,700,000
Foreign net operating loss carryforwards expiration period start year		2024
Foreign net operating loss carryforwards expiration period end year		2028
Valuation allowance	3,495,000	$ 3,495,000	$ 3,965,000
Net increase in valuation allowance from the prior year		500,000
Tax liability, undistributed earnings of foreign subsidiaries	92,000,000	92,000,000
Deferred tax liabilities undistributed earnings of subsidaries	95,000,000	95,000,000
Deferred tax liabilities withholding cost related to earnings	200,000	200,000
Unrecognized tax benefits	0	0	0	$ 0	$ 178,000
Accrued interest	0	0	0	0
Accrued penalties	0	0	$ 0	$ 0
Income Tax Provision [Member]
Income Tax Reconciliation [Line Items]
Net increase in valuation allowance from the prior year		100,000
Currency Translation [Member]
Income Tax Reconciliation [Line Items]
Net increase in valuation allowance from the prior year		400,000
Foreign Country [Member]
Income Tax Reconciliation [Line Items]
Net operating loss carryforwards	9,200,000	9,200,000
Net operating loss carryforwards, definite	$ 1,500,000	$ 1,500,000