Loans (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Schedule Of Accretable Yield Activity Related to Loans Acquired With Evidence Of Credit Quality Deterioration Since Origination Table [Line Items]
Net deferred loan fees and costs and fair value accounting adjustments	$ 6,500	$ (5,000)	$ 6,500	$ (5,000)	$ 2,600
Accretable yield amortized to interest income	(5,477)	(5,199)	(11,076)	(10,656)
Premium finance receivables
Schedule Of Accretable Yield Activity Related to Loans Acquired With Evidence Of Credit Quality Deterioration Since Origination Table [Line Items]
Unearned income portion of premium finance receivables	$ 81,000	$ 64,100	$ 81,000	$ 64,100	$ 69,600