Leases - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($) ft²	Jan. 01, 2019 USD ($)
Lessee Lease Description [Line Items]
Operating lease liabilities | $	$ 57,337
Right-of-use assets | $	39,493
ASU No. 2016-02 [Member]
Lessee Lease Description [Line Items]
Operating lease liabilities | $	60,100	$ 60,100
Right-of-use assets | $	42,500	$ 42,500
ASU No. 2016-02 [Member] | Restatement Adjustment [Member]
Lessee Lease Description [Line Items]
De-recognition of deferred rent to reduce right-of-use assets | $	$ (18,000)
Dublin [Member]
Lessee Lease Description [Line Items]
Office and lab Space on lease | ft²	22,600
Lease expiration date	2019-11
Lease agreement entered date	2018-12
Columbus [Member]
Lessee Lease Description [Line Items]
Office and lab Space on lease | ft²	77,679
Lease expiration date	2026-06
Lease agreement entered date	2018-12
Sublease [Member] | Andover [Member]
Lessee Lease Description [Line Items]
Office and lab Space on lease | ft²	23,102
Lease agreement entered date description	March and July of 2018
Lease expiration date	2020-12
Sublease [Member] | Burlington [Member]
Lessee Lease Description [Line Items]
Office and lab Space on lease | ft²	44,740
Lease expiration date	2022-01
Lease agreement entered date	2018-11
Lease Agreements [Member]
Lessee Lease Description [Line Items]
Lease expiration date	Sep. 30, 2025
Existence of option to extend operating lease [true false]	true
Total rental space | ft²	170,929