Leases - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2019
Lessee Lease Description [Line Items]
Operating lease, description	The Company has operating leases for office, manufacturing and research and development facilities, as well as leases for the ground with which certain manufacturing facilities sit atop. We also have operating leases for office equipment and automobiles.
Operating lease, existence of option to extend	true
Operating lease, options to extend	Excluding ground leases, our leases have remaining lease terms ranging from 1 year to 8 years and may include options to extend the lease for an additional term equal to the original term of the lease.
Minimum
Lessee Lease Description [Line Items]
Operating lease, term of contract	1 year
Minimum | Ground
Lessee Lease Description [Line Items]
Operating lease, term of contract	30 years
Maximum
Lessee Lease Description [Line Items]
Operating lease, term of contract	8 years
Maximum | Ground
Lessee Lease Description [Line Items]
Operating lease, term of contract	45 years