Commitments and Contingencies - Additional Information (Details)	3 Months Ended	12 Months Ended
	Jun. 30, 2016 ft²	Dec. 31, 2016 USD ($) LeaseTerm RenewalOption	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Mar. 31, 2016 ft²	Feb. 28, 2015 ft²
Operating Leased Assets [Line Items]
Total square footage of leased property | ft²						25,000
Additional operating lease term		2 years
Lease expiration date		Dec. 31, 2018
Security deposit		$ 468,000
Restricted cash		468,000
Rent expense		3,900,000	$ 784,000	$ 344,000
Letter of Credit | Bank Of America Merrill Lynch
Operating Leased Assets [Line Items]
Line of credit facility, maximum borrowing capacity		468,000
Collateral Pledged | Certificates of Deposit | Letter of Credit | Bank Of America Merrill Lynch
Operating Leased Assets [Line Items]
Restricted cash		$ 468,000
Office Laboratory Lease
Operating Leased Assets [Line Items]
Total square footage of leased property | ft²					56,000
Description of lease		The Company began incurring rent expense when the landlord delivered possession of the facility to the Company
Operating lease initial term		12 years
Operating lease extended term		13 years 6 months
Operating lease commencement date		2016-03
Operating lease, additional space | ft²	7,000
Additional lease option rights exercised | ft²	41,000
Number of additional renewal terms | LeaseTerm		2
Additional operating lease term		5 years
Office Laboratory Lease | Netherlands
Operating Leased Assets [Line Items]
Operating leases term of expiration		2017-12
Number of renewal options for operating leases | RenewalOption		1