Premises and Equipment - Summary of Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Premises and Equipment [Line Items]
Total Cost	$ 311,945	$ 233,626
Accumulated Depreciation and Amortization	(198,890)	(140,206)
Net	113,055	93,420
Land
Premises and Equipment [Line Items]
Total Cost	25,227	21,762
Buildings and Leasehold Improvements
Premises and Equipment [Line Items]
Total Cost	162,391	125,366
Equipment
Premises and Equipment [Line Items]
Total Cost	$ 124,327	$ 86,498