Premises and Equipment and Lease Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 405,452	$ 380,209
Accumulated depreciation and amortization	(131,520)	(114,649)
Property, Plant and Equipment, Net	273,932	265,560
Depreciation and amortization expense	22,100	21,500	$ 13,700
Right of Use Assets [Abstract]
Operating Lease, Right-of-Use Asset	79,574
Finance Lease, Right-of-Use Asset	1,996
Total right-of-use assets	81,570
Lease Liabilities [Abstract]
Operating Lease, Liability	83,219
Finance Lease, Liability	3,244
Total lease liabilities	86,463
Lease, Cost [Abstract]
Operating Lease, Cost	13,992
Short-term Lease, Cost	295
Finance Lease, Interest Expense	243
Amortization of right-of-use asset	(226)
Sublease Income	(1,463)
Net lease cost	13,293
Operating cash flows related to operating leases	13,609
Financing cash flows related to finance leases	243
Finance Lease, Principal Payments	$ 226
Weighted average remaining lease term
Operating leases	10 years 9 months
Finance leases	8 years 10 months 2 days
Weighted average discount rate
Operating leases	3.07%
Finance leases	7.22%
Operating Leases
2020	$ 13,070
2021	12,439
2022	10,632
2023	9,779
2024	9,667
Thereafter	44,507
Total	100,094
Less: Imputed Interest	(16,875)
Net lease liabilities	83,219
Finance Leases
2020	470
2021	470
2022	470
2023	479
2024	527
Thereafter	2,021
Total	4,437
Less: Imputed Interest	(1,193)
Net lease liabilities	3,244
Land
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	64,814	64,898
Building
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 185,340	170,829
Building | Minimum
Property, Plant and Equipment [Line Items]
Range of Useful Lives	15 years
Building | Maximum
Property, Plant and Equipment [Line Items]
Range of Useful Lives	30 years
Leaseholds and Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 45,398	43,536
Leaseholds and Leasehold Improvements | Minimum
Property, Plant and Equipment [Line Items]
Range of Useful Lives	15 years
Leaseholds and Leasehold Improvements | Maximum
Property, Plant and Equipment [Line Items]
Range of Useful Lives	20 years
Furniture and Equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 109,900	$ 100,946
Furniture and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Range of Useful Lives	3 years
Furniture and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Range of Useful Lives	20 years