Leases (Supplemental Balance Sheet Information) (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jan. 01, 2019
Leases [Abstract]
Operating lease right-of-use assets	$ 39,229	$ 41,754	$ 44,900
Operating lease liabilities	$ 40,221	$ 42,815	$ 46,100
Operating lease, liability, statement of financial position [Extensible List]	us-gaap:OtherLiabilities
Operating lease, right-of-use asset, statement of financial position [Extensible List]	us-gaap:OtherAssets