Premises and Equipment (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Depreciation and amortization of premises and equipment, year to date	$ 36,000	$ 28,500	$ 23,500
Gain on sale and lease-back of property plant equipment	10,300
Deferred gain on sale of property	$ 7,099	$ 0	$ 0