Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
State and foreign net operating loss carry forwards	$ 35,089,000	$ 31,824,000
State tax credits	4,748,000	3,007,000
Valuation allowance	13,177,000	8,733,000
Increase in valuation allowance	4,400,000
Unrecognized tax benefits that would impact effective tax rate	2,200,000
Unrecognized tax benefit that would be offset by tax benefits associated with transfer pricing adjustment	16,300,000
Unrecognized tax benefit with uncertainty about timing of deductibility	8,000,000
Accrued interest	$ 1,300,000	$ 2,000,000
Tax years subject to examination	2012
Minimum
Income Taxes [Line Items]
Period of income tax returns examination after filing	3 years
Maximum
Income Taxes [Line Items]
Period of income tax returns examination after filing	5 years