Premises and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Right-of-use lease assets	$ 38,345	$ 40,675
Accumulated depreciation and amortization	(127,827)	(119,865)
Total premises and equipment, net	484,990	492,384
Land
Property, Plant and Equipment [Line Items]
Premises and equipment	97,152	99,931
Buildings and improvements
Property, Plant and Equipment [Line Items]
Premises and equipment	307,324	309,290
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Premises and equipment	102,342	99,343
Software
Property, Plant and Equipment [Line Items]
Premises and equipment	60,369	56,012
Construction in progress
Property, Plant and Equipment [Line Items]
Premises and equipment	$ 7,285	$ 6,998