Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014
Income Taxes And Tax Related [Line Items]
Unrecognized tax benefits, income tax penalties and interest accrued	$ 0
NEW JERSEY
Income Taxes And Tax Related [Line Items]
State incentives granted	300,000
U.S. [Member]
Income Taxes And Tax Related [Line Items]
Operating tax loss carryforwards, estimated	160,000,000
Operating tax loss carryforwards, estimated expire year	2035
Tax credit carryforward, amount	2,000,000
Tax credit carryforward, amount expire year	2031
Adjustments to additional paid in capital, income tax benefit from share-based compensation	0
U.K. [Member]
Income Taxes And Tax Related [Line Items]
Operating tax loss carryforwards, estimated	$ 12,000,000