Fair Value Accounting - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Sales of marketable securities	$ 0	$ 0	$ 0	$ 0
Cash flow discount rate			16.50%
Increase (decrease) on change in fair value of contingent consideration liability	1,100,000	1,613,000	(5,349,000)	44,013,000
Increase (decrease) to the net loss, per share	$ 0.06	$ 0.09	$ (0.31)	$ 2.67
Estimated fair value of financing obligations	54,693,000		54,693,000		9,342,000
Book value of financing obligations	$ 63,579,000		$ 63,579,000		$ 11,524,000