Commitments and Contingencies - Additional Information (Detail)			1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 21, 2015 USD ($)	Jun. 30, 2015 USD ($) Agreement	Jun. 30, 2014	Jun. 30, 2015 USD ($) Agreement	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Agreement	Jun. 30, 2014 USD ($)
Commitment And Contingencies [Line Items]
Rent expense				$ 219,000	$ 236,000	$ 437,000	$ 467,000
Number of additional license agreements \| Agreement		2		2		2
License agreements fee		$ 2,300,000		$ 2,300,000		$ 2,300,000
Services agreement, days required between notice and termination of agreement			30 days
Maximum [Member]
Commitment And Contingencies [Line Items]
Milestone payments from the Company						19,000,000
Discontinued Operations, Disposed of by Sale [Member]
Commitment And Contingencies [Line Items]
Success fee payable		$ 500,000		$ 500,000		$ 500,000
Percentage of transaction consideration		4.00%		4.00%		4.00%
Discontinued Operations, Disposed of by Sale [Member] \| Subsequent Event [Member]
Commitment And Contingencies [Line Items]
Payment of success fee	$ 450,000
Discontinued Operations, Held-for-sale [Member]
Commitment And Contingencies [Line Items]
Payment of success fee		$ 50,000