Allowance for Loan and Lease Losses - Credit Quality Indicators by Commercial and Industrial Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases, net of unearned income and deferred costs and fees	$ 4,937,822	$ 4,917,550
Commercial and industrial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	42,295
2021	84,067
2022	72,816
2023	89,807
2024	49,454
Prior	284,286
Revolving Loans Amortized Cost Basis	264,462
Revolving Loans Converted to Term	655
Total loans and leases, net of unearned income and deferred costs and fees	887,843
Commercial and industrial | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	42,295
2021	83,851
2022	71,313
2023	88,343
2024	46,007
Prior	283,285
Revolving Loans Amortized Cost Basis	260,678
Revolving Loans Converted to Term	655
Total loans and leases, net of unearned income and deferred costs and fees	876,427
Commercial and industrial | Other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	104
2022	263
2023	1,178
2024	2,821
Prior	136
Revolving Loans Amortized Cost Basis	540
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	5,042
Commercial and industrial | Other | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	112
2022	1,240
2023	286
2024	626
Prior	866
Revolving Loans Amortized Cost Basis	3,244
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	6,374
Commercial and industrial | Agriculture
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,620
2021	13,401
2022	15,126
2023	9,138
2024	5,205
Prior	4,705
Revolving Loans Amortized Cost Basis	46,190
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	95,385
Commercial and industrial | Agriculture | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,520
2021	13,214
2022	14,996
2023	8,135
2024	5,170
Prior	2,395
Revolving Loans Amortized Cost Basis	38,484
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	83,914
Commercial and industrial | Agriculture | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	80
2022	127
2023	109
2024	0
Prior	0
Revolving Loans Amortized Cost Basis	435
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	751
Commercial and industrial | Agriculture | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	100
2021	107
2022	3
2023	894
2024	35
Prior	2,310
Revolving Loans Amortized Cost Basis	7,271
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	10,720
Commercial real estate | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	99,145
2021	249,330
2022	243,136
2023	263,773
2024	346,447
Prior	524,152
Revolving Loans Amortized Cost Basis	392,204
Revolving Loans Converted to Term	2,752
Total loans and leases, net of unearned income and deferred costs and fees	2,120,939
Commercial real estate | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	99,145
2021	247,630
2022	239,644
2023	258,039
2024	340,595
Prior	505,182
Revolving Loans Amortized Cost Basis	381,049
Revolving Loans Converted to Term	2,752
Total loans and leases, net of unearned income and deferred costs and fees	2,074,036
Commercial real estate | Other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	0
2022	2,728
2023	2,400
2024	5,503
Prior	9,253
Revolving Loans Amortized Cost Basis	3,048
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	22,932
Commercial real estate | Other | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	1,700
2022	764
2023	3,334
2024	349
Prior	9,717
Revolving Loans Amortized Cost Basis	8,107
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	23,971
Commercial real estate | Agriculture
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3,538
2021	32,111
2022	45,342
2023	27,017
2024	19,767
Prior	41,108
Revolving Loans Amortized Cost Basis	17,730
Revolving Loans Converted to Term	448
Total loans and leases, net of unearned income and deferred costs and fees	187,061
Commercial real estate | Agriculture | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	2,028
2021	30,493
2022	42,366
2023	23,728
2024	14,147
Prior	39,835
Revolving Loans Amortized Cost Basis	16,842
Revolving Loans Converted to Term	448
Total loans and leases, net of unearned income and deferred costs and fees	169,887
Commercial real estate | Agriculture | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,510
2021	0
2022	2,418
2023	120
2024	1,264
Prior	361
Revolving Loans Amortized Cost Basis	11
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	5,684
Commercial real estate | Agriculture | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	1,618
2022	558
2023	3,169
2024	4,356
Prior	912
Revolving Loans Amortized Cost Basis	877
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	11,490
Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,194
2021	22,565
2022	9,552
2023	3,011
2024	2,165
Prior	5,111
Revolving Loans Amortized Cost Basis	123,869
Revolving Loans Converted to Term	983
Total loans and leases, net of unearned income and deferred costs and fees	168,450
Commercial real estate | Construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,194
2021	22,565
2022	9,552
2023	3,011
2024	2,165
Prior	4,169
Revolving Loans Amortized Cost Basis	121,760
Revolving Loans Converted to Term	983
Total loans and leases, net of unearned income and deferred costs and fees	165,399
Commercial real estate | Construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	0
2022	0
2023	0
2024	0
Prior	603
Revolving Loans Amortized Cost Basis	2,109
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	2,712
Commercial real estate | Construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	0
2022	0
2023	0
2024	0
Prior	339
Revolving Loans Amortized Cost Basis	0
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	339
Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases, net of unearned income and deferred costs and fees	4,724,277	4,697,401
Loans and Leases, gross		3,265,633
Originated | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		3,177,741
Originated | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		29,800
Originated | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		58,092
Originated | Commercial and industrial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		863,199
Originated | Commercial and industrial | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		851,517
Originated | Commercial and industrial | Other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		8,306
Originated | Commercial and industrial | Other | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		3,376
Originated | Commercial and industrial | Agriculture
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		105,786
Originated | Commercial and industrial | Agriculture | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		89,892
Originated | Commercial and industrial | Agriculture | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		1,698
Originated | Commercial and industrial | Agriculture | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		14,196
Originated | Commercial real estate | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		1,899,645
Originated | Commercial real estate | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		1,857,142
Originated | Commercial real estate | Other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		16,623
Originated | Commercial real estate | Other | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		25,880
Originated | Commercial real estate | Agriculture
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		184,701
Originated | Commercial real estate | Agriculture | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		166,888
Originated | Commercial real estate | Agriculture | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		3,173
Originated | Commercial real estate | Agriculture | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		14,640
Originated | Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		212,302
Originated | Commercial real estate | Construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		212,302
Originated | Commercial real estate | Construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Originated | Commercial real estate | Construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases, net of unearned income and deferred costs and fees	$ 213,545	220,149
Loans and Leases, gross		185,993
Acquired | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		183,586
Acquired | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		2,407
Acquired | Commercial and industrial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		39,076
Acquired | Commercial and industrial | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		38,879
Acquired | Commercial and industrial | Other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired | Commercial and industrial | Other | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		197
Acquired | Commercial and industrial | Agriculture
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired | Commercial and industrial | Agriculture | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired | Commercial and industrial | Agriculture | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired | Commercial and industrial | Agriculture | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired | Commercial real estate | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		145,385
Acquired | Commercial real estate | Other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		143,175
Acquired | Commercial real estate | Other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired | Commercial real estate | Other | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		2,210
Acquired | Commercial real estate | Agriculture
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		197
Acquired | Commercial real estate | Agriculture | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		197
Acquired | Commercial real estate | Agriculture | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired | Commercial real estate | Agriculture | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired | Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		1,335
Acquired | Commercial real estate | Construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		1,335
Acquired | Commercial real estate | Construction | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		0
Acquired | Commercial real estate | Construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases, gross		$ 0