Commitments and Contingencies - Additional Information (Detail)	1 Months Ended
	Oct. 31, 2015 ft²	Sep. 30, 2015 USD ($) Patent	Jul. 31, 2013 ft²	Sep. 30, 2015 EUR (€)	Apr. 30, 2015 ft²	Apr. 30, 2014 USD ($)
Commitments and Contingencies [Line Items]
Office space under operating lease | ft²					24,560
License agreement, upfront payment						$ 1,500,000
License agreement, maximum agreed additional payments upon achievement of development milestones						$ 4,500,000
Patents allegedly infringed upon, number | Patent		2
For May 2014 through December 2015
Commitments and Contingencies [Line Items]
Facilities leases, base rent per month		$ 74,050
For January 2016 through February 2016
Commitments and Contingencies [Line Items]
Facilities leases, base rent per month		85,818
For March 2016 through February 2018
Commitments and Contingencies [Line Items]
Facilities leases, base rent per month		82,518
For March 2018 through February 2021
Commitments and Contingencies [Line Items]
Facilities leases, base rent per month		85,030
Europe
Commitments and Contingencies [Line Items]
Facilities leases, base rent per month		$ 72,500		€ 64,500
Europe | Lease Agreements
Commitments and Contingencies [Line Items]
Office space under operating lease | ft²			33,000
Lease, expiration date			Jul. 31, 2023
Subsequent Event | Europe | Lease Agreements
Commitments and Contingencies [Line Items]
Additional office space under operating lease | ft²	9,000
Subsequent Event | Europe | Lease Agreement Adjacent to Aachen Facility
Commitments and Contingencies [Line Items]
Office space under operating lease | ft²	30,000
Lease, expiration date	Jun. 30, 2016