Premises, Furniture, and Equipment (Details) - Rental Expense - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Lease expense charged to operations		$ 11,207	$ 6,850	$ 4,669
Accretion of operating lease intangible	[1]	(1,171)	(1,144)	(453)
Accretion of deferred gain on sale-leaseback transaction	[1]	(1,473)	0	0
Rental income from premises leased to others	[1]	(527)	(606)	(541)
Net operating lease expense		$ 8,036	$ 5,100	$ 3,675

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