Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Tax Contingency [Line Items]
Provision for income taxes	$ 1,066,000	$ 771,000	$ 1,514,000	$ 1,363,000
Unrecognized tax benefits	3,600,000		3,600,000
Unrecognized tax benefits, interest and penalties accrued	1,400,000		1,400,000
Provision for income and foreign withholding taxes	0		0
Income tax benefit			$ 0	$ 0
Minimum [Member]
Income Tax Contingency [Line Items]
Open audit year			2006
Maximum [Member]
Income Tax Contingency [Line Items]
Open audit year			2014