(Reserve for Unfunded Commitments) (Detail) - SEC Schedule, 12-09, Allowance, Credit Loss [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 2,511	$ 2,294	$ 2,506	$ 2,362
Provision charged to expense	26	302	31	234
Ending balance	$ 2,537	$ 2,596	$ 2,537	$ 2,596