Premises, Furniture, and Equipment (Details) - Rental Expense - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Property, Plant and Equipment [Abstract]
Lease expense charged to operations		$ 4,559	$ 1,727
Accretion of operating lease intangible	[1]	(295)	(286)
Accretion of deferred gain on sale-leaseback transaction	[1]	(1,473)	0
Rental income from premises leased to others	[1]	(181)	(158)
Net operating lease expense		$ 2,610	$ 1,283

[1] Included as reductions to net occupancy and equipment expense in the Condensed Consolidated Statements of Income.