Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Accounting Policies [Abstract]
Unrealized gain (loss) on available-for-sale investments	$ 111,000	$ 49,000
Realized investment gains or losses	0	$ 0
Investments owned, at fair value	0
Long-term debt, fair value	$ 92,300,000		$ 140,100,000
Warrants exercise price	$ 0.05