Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Federal income tax rate		21.00%	21.00%	35.00%
Federal net operating loss carryforwards expiration period start		2031
Federal net operating loss carryforwards expiration period end		2033
State operating loss carryforwards expiration period start		2028
State net operating loss carryingforwards period end		2037
Provisional decrease in federal income tax				$ 17,300,000
Net adjustment to deferred income tax benefit				17,300,000
U.S. transition tax	$ 200,000
Tax cuts and jobs act, provisional accounting for changes in income tax expense (benefit)			$ 17,500,000	17,300,000
Unrecognized tax benefits due to uncertain tax positions		$ 6,700,000	$ 6,000,000	$ 6,300,000
Unrecognized tax benefits which would effect effective tax rate if recognized		1,200,000
Accrued interest and penalties related to uncertain tax positions		0
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Federal Net operating loss carrying forward		89,000,000
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Federal Net operating loss carrying forward		$ 6,000,000
Foreign Tax Authority | Earliest Tax Year
Operating Loss Carryforwards [Line Items]
Income tax year under examination		2007
Foreign Tax Authority | Latest Tax Year
Operating Loss Carryforwards [Line Items]
Income tax year under examination		2018
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Federal Net operating loss carrying forward		$ 60,000,000