Premises, Equipment and Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Premises and Equipment [Abstract]
Premises and equipment before accumulated depreciation	$ 179,910	$ 177,385
Accumulated depreciation	104,279	98,415
Total premises and equipment	75,631	78,970
Operating lease ROU assets	$ 34,800
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssets
Net Lease Cost [Abstract]
Operating lease cost	$ 7,239
Variable lease cost	2,231
Short-term lease cost	356
Sublease income	(448)
Total operating lease cost	9,378
Future Minimum Rental Commitments Related to Non-cancelable Operating Leases [Abstract]
2020	7,435
2021	6,646
2022	5,870
2023	4,969
2024	4,365
Thereafter	12,876
Total lease payments	42,161
Less: interest	(4,838)
Present value of lease liabilities	$ 37,323
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilities
Additional Information Related to Operating Leases [Abstract]
Weighted average remaining lease term, in years	7 years 8 months 8 days
Weighted average discount rate	3.00%
Cash paid for amounts included in the measurement of lease liabilities [Abstract]
Operating cash flows from operating leases	$ 6,211
ROU assets obtained in exchange for lease liabilities	41,008
Rental expense	8,000	8,600	$ 8,500
Land, Buildings and Improvements [Member]
Premises and Equipment [Abstract]
Premises and equipment before accumulated depreciation	121,479	121,808
Equipment [Member]
Premises and Equipment [Abstract]
Premises and equipment before accumulated depreciation	$ 58,431	$ 55,577
Equipment [Member] | Minimum [Member]
Premises and Equipment [Abstract]
Property, plant and equipment, useful life	3 years
Equipment [Member] | Maximum [Member]
Premises and Equipment [Abstract]
Property, plant and equipment, useful life	10 years
Building and Improvements [Member] | Minimum [Member]
Premises and Equipment [Abstract]
Property, plant and equipment, useful life	5 years
Building and Improvements [Member] | Maximum [Member]
Premises and Equipment [Abstract]
Property, plant and equipment, useful life	20 years