Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
Summary Of Significant Accounting Policies [Line Items]
Net lease assets	$ 30,619
Net lease liabilities	$ 41,632
ASC 842 [Member]
Summary Of Significant Accounting Policies [Line Items]
Net lease assets		$ 26,087
Net lease liabilities		$ 37,600