Leases - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2019 USD ($)
Operating lease option to extend	options to extend the leases for up to 10 years, and some of which include options to terminate the leases within 1 year.
Sublease Income	$ 10,000
Lessee operating lease lease not yet commenced undiscounted cash	$ 144,000
Operating lease lease term	3 years
Sublease option to terminate	The sublease expires in 2021 with an option to terminate and no option to extend.
Maximum [Member]
Operating lease remaining lease term	32 years
Minimum [Member]
Operating lease remaining lease term	1 year