Leases - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Jan. 01, 2019
Lessee Lease Description [Line Items]
Lease, option to terminate	leases can be terminated with 30-day prior written notice
Lease termination period with prior written notice	30 days
ASU 2016-02 [Member]
Lessee Lease Description [Line Items]
Operating lease assets and liabilities		$ 5.4