Commitments and Contingencies - Additional Information (Detail)		1 Months Ended			12 Months Ended
	Dec. 09, 2015 USD ($)	Oct. 31, 2015 ft²	Sep. 30, 2015 Patent	Jul. 31, 2013 ft²	Mar. 31, 2016 USD ($) ft² Amendment	Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Apr. 30, 2016 USD ($)	Mar. 31, 2016 EUR (€) ft² Amendment	Dec. 31, 2015 USD ($)	Apr. 30, 2014 USD ($)
Commitments and Contingencies [Line Items]
Office space under operating lease | ft²					125,560				125,560
Purchase price of property amount	$ 16,500,000
Number of amendments | Amendment					2				2
Rent expense					$ 2,400,000	$ 1,900,000	$ 1,500,000
License agreement, upfront payment										$ 500,000	$ 1,500,000
License agreement, maximum agreed additional payments upon achievement of development milestones										2,000,000	$ 4,500,000
License agreement, milestone payment										$ 600,000
Payments obligations on achievement of certain development and regulatory milestones					3,000,000
Patents allegedly infringed upon, number | Patent			2
Subsequent Event
Commitments and Contingencies [Line Items]
License agreement, milestone payment								$ 500,000
Europe
Commitments and Contingencies [Line Items]
Facilities leases, base rent per month					73,000				€ 64,500
Lease Agreements | Europe
Commitments and Contingencies [Line Items]
Office space under operating lease | ft²				33,000
Lease, expiration date				Jul. 31, 2023
Additional office space under operating lease | ft²		9,000
Lease Agreement Adjacent To Aachen Facility | Europe
Commitments and Contingencies [Line Items]
Office space under operating lease | ft²		30,000
Lease, expiration date		Jun. 30, 2016
For March 2016 through February 2018
Commitments and Contingencies [Line Items]
Facilities leases, base rent per month					84,914
For March 2018 through February 2021
Commitments and Contingencies [Line Items]
Facilities leases, base rent per month					$ 87,530