Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Jul. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Expenses [Line Items]
Valuation allowance		$ 13,000,000	$ 7,800,000	$ 8,400,000
U.S. federal, net operating loss carryforwards		153,000,000
State net operating loss carryforwards		73,700,000
Excess tax benefits from stock options included in deferred tax assets for federal net operating losses		49,900,000
Excess tax benefits from stock options included in deferred tax assets for state net operating losses		13,500,000
Accumulated unremitted earnings		13,600,000	12,900,000	9,800,000
Unrecognized tax benefits		1,154,000	672,000	$ 353,000	$ 239,000
Accrued interest on income tax expense		$ 83,000	$ 43,000
2014 [Member]
Income Tax Expenses [Line Items]
Tax rate applicable for R&D activities		12.50%
2015 and Thereafter [Member]
Income Tax Expenses [Line Items]
Tax rate applicable for R&D activities		12.00%
Israeli Tax Authority [Member]
Income Tax Expenses [Line Items]
Corporate tax rate		26.50%
Israeli Tax Authority [Member] | Previous [Member]
Income Tax Expenses [Line Items]
Corporate tax rate	25.00%
Israeli Tax Authority [Member] | Non R&D Activities [Member]
Income Tax Expenses [Line Items]
Corporate tax rate		26.50%
Israeli Tax Authority [Member] | 2011 [Member]
Income Tax Expenses [Line Items]
Tax rate applicable for R&D activities		15.00%
Israeli Tax Authority [Member] | 2012 [Member]
Income Tax Expenses [Line Items]
Tax rate applicable for R&D activities		15.00%
Israeli Tax Authority [Member] | 2013 [Member]
Income Tax Expenses [Line Items]
Tax rate applicable for R&D activities		12.50%
Israeli Tax Authority [Member] | 2014 [Member]
Income Tax Expenses [Line Items]
Tax rate applicable for R&D activities		16.00%
Maximum [Member] | State [Member]
Income Tax Expenses [Line Items]
Expiration of net operating loss carryforwards		2035
Maximum [Member] | Federal [Member]
Income Tax Expenses [Line Items]
Expiration of net operating loss carryforwards		2035
Maximum [Member] | Israeli Tax Authority [Member]
Income Tax Expenses [Line Items]
Tax years		2010
Minimum [Member] | State [Member]
Income Tax Expenses [Line Items]
Expiration of net operating loss carryforwards		2018
Minimum [Member] | Federal [Member]
Income Tax Expenses [Line Items]
Expiration of net operating loss carryforwards		2023
Minimum [Member] | Israeli Tax Authority [Member]
Income Tax Expenses [Line Items]
Tax years		2006