Subsequent Events - Additional Information (Detail) - USD ($)		1 Months Ended
	Oct. 03, 2016	Jun. 30, 2016	Apr. 30, 2013
Maximum [Member]
Subsequent Event [Line Items]
Additional payments to Summit on successful achievement		$ 20,000,000	$ 20,000,000
Subsequent Event [Member] | Collaboration and License Agreement [Member]
Subsequent Event [Line Items]
Percentage of budgeted research and development cost allocation	45.00%
Maximum percentage of budgeted research and development cost	110.00%
Subsequent Event [Member] | Summit [Member] | Collaboration and License Agreement [Member]
Subsequent Event [Line Items]
Upfront milestone payment	$ 40,000,000
One-time option fee	$ 10,000,000
Percentage of budgeted research and development cost allocation	55.00%
Subsequent Event [Member] | Summit [Member] | Maximum [Member] | Collaboration and License Agreement [Member]
Subsequent Event [Line Items]
Additional payments to Summit on successful achievement	$ 192,000,000
Development and regulatory milestone payments	290,000,000
Sales milestone payments	330,000,000
Regulatory milestone payments upon exercise of option	7,000,000
Sales milestone payments upon exercise of option	$ 82,500,000