Allowance for Credit Losses - Credit Quality Indicators by Commercial and Industrial Loans (Details) - USD ($) $ in Thousands	Jun. 30, 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	$ 5,424,285	$ 4,917,550
Commercial and industrial | Commercial and industrial other
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	52,579
2021	82,777
2022	68,901
2023	75,359
2024	45,701
Prior	206,176
Revolving Loans Amortized Cost Basis	312,895
Revolving Loans Converted to Term	402
Total loans and leases, net of unearned income and deferred costs and fees	844,791
Commercial and industrial | Commercial and industrial other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	52,554
2021	82,412
2022	67,418
2023	73,935
2024	42,652
Prior	205,483
Revolving Loans Amortized Cost Basis	308,949
Revolving Loans Converted to Term	402
Total loans and leases, net of unearned income and deferred costs and fees	833,805
Commercial and industrial | Commercial and industrial other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	259
2022	254
2023	1,148
2024	2,806
Prior	0
Revolving Loans Amortized Cost Basis	930
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	5,397
Commercial and industrial | Commercial and industrial other | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	25
2021	106
2022	1,229
2023	276
2024	243
Prior	694
Revolving Loans Amortized Cost Basis	3,016
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	5,589
Commercial and industrial | PPP loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	465,627
2021	0
2022	0
2023	0
2024	0
Prior	0
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	465,627
Commercial and industrial | PPP loans | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	465,627
2021	0
2022	0
2023	0
2024	0
Prior	0
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	465,627
Commercial and industrial | PPP loans | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	0
2022	0
2023	0
2024	0
Prior	0
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	0
Commercial and industrial | PPP loans | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	0
2022	0
2023	0
2024	0
Prior	0
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	0
Commercial and industrial | Agriculture
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	7,406
2021	10,664
2022	11,373
2023	7,553
2024	4,627
Prior	2,632
Revolving Loans Amortized Cost Basis	49,493
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	93,748
Commercial and industrial | Agriculture | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	7,306
2021	10,485
2022	11,254
2023	6,487
2024	4,627
Prior	2,632
Revolving Loans Amortized Cost Basis	43,111
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	85,902
Commercial and industrial | Agriculture | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	79
2022	119
2023	58
2024	0
Prior	0
Revolving Loans Amortized Cost Basis	388
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	644
Commercial and industrial | Agriculture | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	100
2021	100
2022	0
2023	1,008
2024	0
Prior	0
Revolving Loans Amortized Cost Basis	5,994
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	7,202
Commercial real estate | Commercial and industrial other
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	143,733
2021	248,437
2022	240,976
2023	267,021
2024	349,904
Prior	218,222
Revolving Loans Amortized Cost Basis	684,183
Revolving Loans Converted to Term	1,975
Total loans and leases, net of unearned income and deferred costs and fees	2,154,451
Commercial real estate | Commercial and industrial other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	143,733
2021	246,737
2022	233,379
2023	261,009
2024	338,157
Prior	215,469
Revolving Loans Amortized Cost Basis	655,061
Revolving Loans Converted to Term	1,975
Total loans and leases, net of unearned income and deferred costs and fees	2,095,520
Commercial real estate | Commercial and industrial other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	0
2022	6,836
2023	2,400
2024	11,251
Prior	587
Revolving Loans Amortized Cost Basis	8,986
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	30,060
Commercial real estate | Commercial and industrial other | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	1,700
2022	761
2023	3,612
2024	496
Prior	2,166
Revolving Loans Amortized Cost Basis	20,136
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	28,871
Commercial real estate | Agriculture
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	11,006
2021	32,279
2022	45,536
2023	25,119
2024	19,509
Prior	6,374
Revolving Loans Amortized Cost Basis	53,445
Revolving Loans Converted to Term	442
Total loans and leases, net of unearned income and deferred costs and fees	193,710
Commercial real estate | Agriculture | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	9,186
2021	32,279
2022	42,572
2023	21,835
2024	17,537
Prior	6,374
Revolving Loans Amortized Cost Basis	51,488
Revolving Loans Converted to Term	442
Total loans and leases, net of unearned income and deferred costs and fees	181,713
Commercial real estate | Agriculture | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,820
2021	0
2022	2,408
2023	119
2024	1,250
Prior	0
Revolving Loans Amortized Cost Basis	350
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	5,947
Commercial real estate | Agriculture | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	0
2022	556
2023	3,165
2024	722
Prior	0
Revolving Loans Amortized Cost Basis	1,607
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	6,050
Commercial real estate | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	7,653
2021	19,325
2022	9,494
2023	2,789
2024	2,099
Prior	3,131
Revolving Loans Amortized Cost Basis	148,449
Revolving Loans Converted to Term	243
Total loans and leases, net of unearned income and deferred costs and fees	193,183
Commercial real estate | Construction | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	7,653
2021	19,325
2022	9,494
2023	2,789
2024	2,099
Prior	3,131
Revolving Loans Amortized Cost Basis	145,422
Revolving Loans Converted to Term	243
Total loans and leases, net of unearned income and deferred costs and fees	190,156
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	0
Revolving Loans Amortized Cost Basis	2,693
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	2,693
Commercial real estate | Construction | Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2021	0
2022	0
2023	0
2024	0
Prior	0
Revolving Loans Amortized Cost Basis	334
Revolving Loans Converted to Term	0
Total loans and leases, net of unearned income and deferred costs and fees	$ 334
Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases, net of unearned income and deferred costs and fees		4,701,046
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
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases, net of unearned income and deferred costs and fees		968,985
Originated | Commercial and industrial | Commercial and industrial other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		863,199
Originated | Commercial and industrial | Commercial and industrial other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		851,517
Originated | Commercial and industrial | Commercial and industrial other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		8,306
Originated | Commercial and industrial | 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
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases, net of unearned income and deferred costs and fees		2,296,648
Originated | Commercial real estate | Commercial and industrial other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		1,899,645
Originated | Commercial real estate | Commercial and industrial other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		1,857,142
Originated | Commercial real estate | Commercial and industrial other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		16,623
Originated | Commercial real estate | Commercial and industrial 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		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
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases, net of unearned income and deferred costs and fees		39,076
Acquired | Commercial and industrial | Commercial and industrial other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		39,076
Acquired | Commercial and industrial | Commercial and industrial other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		38,879
Acquired | Commercial and industrial | Commercial and industrial other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		0
Acquired | Commercial and industrial | 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
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases, net of unearned income and deferred costs and fees		146,917
Acquired | Commercial real estate | Commercial and industrial other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		145,385
Acquired | Commercial real estate | Commercial and industrial other | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		143,175
Acquired | Commercial real estate | Commercial and industrial other | Special Mention
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases, gross		0
Acquired | Commercial real estate | Commercial and industrial 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