Net Operating Loss Carryforwards (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)
U.S. Federal and state income tax
Operating Loss Carryforwards [Line Items]
Operating loss carryforward, amount	$ 80,337
U.S. Federal and state income tax | Minimum
Operating Loss Carryforwards [Line Items]
Operating loss carryforward, year of expiration	2019
U.S. Federal and state income tax | Maximum
Operating Loss Carryforwards [Line Items]
Operating loss carryforward, year of expiration	2037
Foreign
Operating Loss Carryforwards [Line Items]
Operating loss carryforward, amount	$ 15,912
Foreign | Minimum
Operating Loss Carryforwards [Line Items]
Operating loss carryforward, year of expiration	2019
Foreign | Maximum
Operating Loss Carryforwards [Line Items]
Operating loss carryforward, year of expiration	2038
Indefinite
Operating Loss Carryforwards [Line Items]
Operating loss carryforward, amount	$ 5,776
Operating loss carryforward, year of expiration	Indefinite