Subsequent Events - Additional Information (Detail) - Subsequent $ in Millions	Jan. 31, 2016 USD ($)
Bristol-Myers Squibb Company ("BMS") and Pfizer Inc. ("Pfizer")
Subsequent Event [Line Items]
Upfront payment receivable	$ 15.0
Potential regulatory and sales-based milestone payments receivable	90.0
Bayer Pharma AG
Subsequent Event [Line Items]
Upfront payment receivable	$ 5.0