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Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Increase in valuation allowance	$ 34,400,000	$ 30,500,000	$ 12,300,000
Federal and state net operating loss carryforwards	91,683,000	71,256,000
Foreign net operating loss carryforwards	$ 21,295,000	$ 15,052,000
Tax at statutory federal rate	21.00%	34.00%	34.00%
Percentage of ownership changes	0.00%
Unrecognized tax benefits	$ 28,000,000
Unrecognized tax benefits that would affect effective tax rate	500,000
Accrued interest, unrecognized tax benefits	$ 0		$ 0
Unrecognized tax benefits description	The Company does not anticipate a material change to its unrecognized tax benefits over the next twelve months that would affect the Company’s effective tax rate.
Earliest Tax Year [Member]
Income Taxes [Line Items]
Foreign statute of limitation generally remains open in the year	2009
Latest Tax Year [Member]
Income Taxes [Line Items]
Foreign statute of limitation generally remains open in the year	2018
ASU 2016-09 [Member]
Income Taxes [Line Items]
Increase in valuation allowance	$ 19,500,000
Retrospective increase in deferred tax assets for previously unrecognized excess tax benefits	19,500,000
Maximum [Member]
Income Taxes [Line Items]
Tax at statutory federal rate		35.00%
Foreign net operating loss [Member]
Income Taxes [Line Items]
Foreign net operating loss carryforwards	$ 86,300,000
Foreign net operating loss [Member] \| Minimum [Member]
Income Taxes [Line Items]
Operating loss carryforwards expiration year	2019
Foreign net operating loss [Member] \| Maximum [Member]
Income Taxes [Line Items]
Operating loss carryforwards expiration year	2028
Federal [Member]
Income Taxes [Line Items]
Federal and state net operating loss carryforwards	$ 400,300,000
Operating loss carryforwards expiration year	2026
Other tax credit carryforwards	$ 46,400,000
Other tax credit carryforwards expiration year	2019
State [Member]
Income Taxes [Line Items]
Federal and state net operating loss carryforwards	$ 148,100,000
Operating loss carryforwards expiration year	2019
State [Member] \| California [Member]
Income Taxes [Line Items]
Other tax credit carryforwards	$ 26,300,000