Loans - Schedule of Recorded Investment in Criticized Loans by Class and Credit Quality Indicator (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		$ 8,936,200,000
Non-owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	$ 273.2
2019	332.4
2018	226.6
2017	122.1
2016	171.2
Prior	415.0
Revolving Loans Amortized Cost Basis	20.0
Total	1,560.5
Commercial Real Estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		3,487,800,000
Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	3,593,800,000	3,487,800,000
Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	61.0
2019	83.6
2018	51.6
2017	38.1
2016	11.1
Prior	34.0
Revolving Loans Amortized Cost Basis	5.9
Total	285.3
Loans held for investment	285,300,000	302,100,000
Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	52.8
2019	99.5
2018	27.2
2017	6.4
2016	0.3
Prior	0.3
Revolving Loans Amortized Cost Basis	59.7
Total	246.2
Loans held for investment	246,200,000	244,100,000
Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	96.0
2019	232.7
2018	87.6
2017	22.4
2016	9.8
Prior	0.6
Revolving Loans Amortized Cost Basis	10.7
Total	459.8
Loans held for investment	459,800,000	431,500,000
Total construction
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		977,700,000
Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,287,600,000	1,246,100,000
Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	991,300,000	977,700,000
Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	26.1
2019	65.8
2018	36.9
2017	23.4
2016	18.9
Prior	43.7
Revolving Loans Amortized Cost Basis	9.4
Total	224.2
Loans held for investment	224,200,000	226,600,000
Real Estate Loan
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		5,938,200,000
Total real estate loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	6,096,900,000	5,938,200,000
Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	184.7
2019	239.2
2018	152.7
2017	100.5
2016	67.8
Prior	57.0
Revolving Loans Amortized Cost Basis	0
Total	801.9
Loans held for investment	801,900,000	784,600,000
Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	29.8
2019	39.5
2018	40.0
2017	17.1
2016	8.0
Prior	11.2
Revolving Loans Amortized Cost Basis	23.7
Total	169.3
Loans held for investment	169,300,000	179,000,000.0
Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	138.1
Loans held for investment	70,600,000	81,600,000
Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	1,041,800,000	1,045,200,000
Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	2,648,600,000	1,673,700,000
Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment	282,800,000	279,100,000
Owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	229.1
2019	347.6
2018	250.1
2017	166.9
2016	207.1
Prior	477.7
Revolving Loans Amortized Cost Basis	16.3
Total	1,694.8
Multi-family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	68.5
2019	76.7
2018	31.0
2017	30.4
2016	27.8
Prior	101.5
Revolving Loans Amortized Cost Basis	2.6
Total	338.5
Commercial and floor plans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	1,360.9
2019	216.9
2018	175.9
2017	108.7
2016	63.9
Prior	121.6
Revolving Loans Amortized Cost Basis	252.1
Total	2,300.0
Commercial purpose secured by 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	41.0
2019	72.8
2018	49.1
2017	28.1
2016	20.2
Prior	50.8
Revolving Loans Amortized Cost Basis	20.8
Total	282.8
Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	42.4
2019	32.7
2018	20.8
2017	8.1
2016	4.4
Prior	2.1
Revolving Loans Amortized Cost Basis	170.6
Total	281.1
Loans held for investment		279,100,000
Residential 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	191.0
2019	129.6
2018	84.3
2017	73.3
2016	86.2
Prior	309.7
Revolving Loans Amortized Cost Basis	0
Total	874.1
Consumer Home Equity and HELOC
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	8.7
2019	10.6
2018	10.5
2017	13.2
2016	5.7
Prior	16.8
Revolving Loans Amortized Cost Basis	348.0
Total	413.5
Pass
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		8,548,800,000
Pass | Non-owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	257.6
2019	326.4
2018	224.7
2017	120.7
2016	169.4
Prior	385.0
Revolving Loans Amortized Cost Basis	20.0
Total	1,503.8
Pass | Commercial Real Estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		3,305,000,000.0
Pass | Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	60.2
2019	83.4
2018	50.3
2017	36.5
2016	11.1
Prior	32.5
Revolving Loans Amortized Cost Basis	5.3
Total	279.3
Loans held for investment		295,400,000
Pass | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	52.5
2019	99.5
2018	26.0
2017	6.4
2016	0.3
Prior	0.3
Revolving Loans Amortized Cost Basis	59.7
Total	244.7
Loans held for investment		241,000,000.0
Pass | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	96.0
2019	231.9
2018	85.7
2017	22.4
2016	9.8
Prior	0.5
Revolving Loans Amortized Cost Basis	10.7
Total	457.0
Loans held for investment		428,300,000
Pass | Total construction
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		964,700,000
Pass | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		1,235,400,000
Pass | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	24.4
2019	52.1
2018	32.1
2017	20.2
2016	15.0
Prior	34.0
Revolving Loans Amortized Cost Basis	6.3
Total	184.1
Loans held for investment		185,700,000
Pass | Real Estate Loan
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		5,690,800,000
Pass | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		781,500,000
Pass | Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		177,700,000
Pass | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		81,600,000
Pass | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		1,040,800,000
Pass | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		1,569,400,000
Pass | Owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	219.9
2019	333.3
2018	232.7
2017	160.3
2016	178.5
Prior	445.1
Revolving Loans Amortized Cost Basis	15.5
Total	1,585.3
Pass | Commercial and floor plans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	1,344.6
2019	196.5
2018	166.4
2017	105.5
2016	53.8
Prior	115.2
Revolving Loans Amortized Cost Basis	236.3
Total	2,218.3
Pass | Commercial purpose secured by 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	40.5
2019	67.1
2018	44.2
2017	27.0
2016	18.4
Prior	47.8
Revolving Loans Amortized Cost Basis	20.2
Total	265.2
Pass | Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	33.8
2019	28.8
2018	15.5
2017	6.5
2016	4.0
Prior	1.3
Revolving Loans Amortized Cost Basis	154.4
Total	244.3
Loans held for investment		247,800,000
Other Assets Especially Mentioned
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		157,500,000
Other Assets Especially Mentioned | Non-owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	3.2
2018	1.3
2017	0.1
2016	0.5
Prior	15.4
Revolving Loans Amortized Cost Basis	0
Total	20.5
Other Assets Especially Mentioned | Commercial Real Estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		84,700,000
Other Assets Especially Mentioned | Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0.5
2019	0.1
2018	0.1
2017	1.0
2016	0
Prior	1.2
Revolving Loans Amortized Cost Basis	0.2
Total	3.1
Loans held for investment		3,800,000
Other Assets Especially Mentioned | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Total	0
Loans held for investment		900,000
Other Assets Especially Mentioned | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0
2018	1.5
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Total	1.5
Loans held for investment		1,700,000
Other Assets Especially Mentioned | Total construction
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		6,400,000
Other Assets Especially Mentioned | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		2,600,000
Other Assets Especially Mentioned | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	1.6
2019	2.8
2018	1.3
2017	2.2
2016	0.4
Prior	3.9
Revolving Loans Amortized Cost Basis	1.0
Total	13.2
Loans held for investment		14,300,000
Other Assets Especially Mentioned | Real Estate Loan
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		108,000,000.0
Other Assets Especially Mentioned | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		200,000
Other Assets Especially Mentioned | Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		400,000
Other Assets Especially Mentioned | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		0
Other Assets Especially Mentioned | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		600,000
Other Assets Especially Mentioned | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		40,400,000
Other Assets Especially Mentioned | Owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	2.9
2019	7.1
2018	7.5
2017	0.9
2016	9.5
Prior	13.9
Revolving Loans Amortized Cost Basis	0.3
Total	42.1
Other Assets Especially Mentioned | Commercial and floor plans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	6.0
2019	1.6
2018	1.0
2017	2.4
2016	5.1
Prior	0.3
Revolving Loans Amortized Cost Basis	4.0
Total	20.4
Other Assets Especially Mentioned | Commercial purpose secured by 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0.3
2019	2.0
2018	0.3
2017	0.6
2016	0.5
Prior	1.2
Revolving Loans Amortized Cost Basis	0.4
Total	5.3
Other Assets Especially Mentioned | Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	2.7
2019	1.7
2018	0.4
2017	0.1
2016	0.1
Prior	0.4
Revolving Loans Amortized Cost Basis	7.6
Total	13.0
Loans held for investment		8,500,000
Substandard
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		224,000,000.0
Substandard | Non-owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	15.6
2019	2.8
2018	0.4
2017	1.3
2016	1.3
Prior	14.6
Revolving Loans Amortized Cost Basis	0
Total	36.0
Substandard | Commercial Real Estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		97,300,000
Substandard | Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0.3
2019	0.1
2018	1.2
2017	0.6
2016	0
Prior	0.2
Revolving Loans Amortized Cost Basis	0.4
Total	2.8
Loans held for investment		1,900,000
Substandard | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0.3
2019	0
2018	1.2
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Total	1.5
Loans held for investment		2,200,000
Substandard | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0.8
2018	0
2017	0
2016	0
Prior	0.1
Revolving Loans Amortized Cost Basis	0
Total	0.9
Loans held for investment		1,500,000
Substandard | Total construction
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		5,600,000
Substandard | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		7,800,000
Substandard | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0.1
2019	8.9
2018	3.5
2017	1.0
2016	3.5
Prior	5.8
Revolving Loans Amortized Cost Basis	2.1
Total	24.9
Loans held for investment		26,600,000
Substandard | Real Estate Loan
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		137,300,000
Substandard | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		2,900,000
Substandard | Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		800,000
Substandard | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		0
Substandard | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		3,700,000
Substandard | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		60,300,000
Substandard | Owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	6.1
2019	7.2
2018	9.7
2017	5.6
2016	18.7
Prior	18.6
Revolving Loans Amortized Cost Basis	0.5
Total	66.4
Substandard | Commercial and floor plans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	8.4
2019	13.2
2018	8.3
2017	0.7
2016	4.9
Prior	3.5
Revolving Loans Amortized Cost Basis	11.5
Total	50.5
Substandard | Commercial purpose secured by 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0.2
2019	3.6
2018	4.5
2017	0.5
2016	1.3
Prior	1.8
Revolving Loans Amortized Cost Basis	0.1
Total	12.0
Substandard | Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	5.9
2019	2.1
2018	4.9
2017	1.4
2016	0.3
Prior	0.4
Revolving Loans Amortized Cost Basis	8.6
Total	23.6
Loans held for investment		22,700,000
Doubtful
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		5,900,000
Doubtful | Non-owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0
2018	0.2
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Total	0.2
Doubtful | Commercial Real Estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		800,000
Doubtful | Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0.1
Revolving Loans Amortized Cost Basis	0
Total	0.1
Loans held for investment		1,000,000.0
Doubtful | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Total	0
Loans held for investment		0
Doubtful | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0
2018	0.4
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Total	0.4
Loans held for investment		0
Doubtful | Total construction
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		1,000,000.0
Doubtful | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		300,000
Doubtful | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	2.0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Total	2.0
Loans held for investment		0
Doubtful | Real Estate Loan
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		2,100,000
Doubtful | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		0
Doubtful | Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		100,000
Doubtful | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		0
Doubtful | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		100,000
Doubtful | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		3,600,000
Doubtful | Owner occupied
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0.2
2019	0
2018	0.2
2017	0.1
2016	0.4
Prior	0.1
Revolving Loans Amortized Cost Basis	0
Total	1.0
Doubtful | Commercial and floor plans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	1.9
2019	5.6
2018	0.2
2017	0.1
2016	0.1
Prior	2.6
Revolving Loans Amortized Cost Basis	0.3
Total	10.8
Doubtful | Commercial purpose secured by 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0.1
2018	0.1
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0.1
Total	0.3
Doubtful | Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0.1
2018	0
2017	0.1
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Total	0.2
Loans held for investment		100,000
Total Criticized Loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		387,400,000
Total Criticized Loans | Commercial Real Estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		182,800,000
Total Criticized Loans | Land acquisition & development
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		6,700,000
Total Criticized Loans | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		3,100,000
Total Criticized Loans | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		3,200,000
Total Criticized Loans | Total construction
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		13,000,000.0
Total Criticized Loans | Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		10,700,000
Total Criticized Loans | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		40,900,000
Total Criticized Loans | Real Estate Loan
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		247,400,000
Total Criticized Loans | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		3,100,000
Total Criticized Loans | Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		1,300,000
Total Criticized Loans | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		0
Total Criticized Loans | Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		4,400,000
Total Criticized Loans | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		104,300,000
Total Criticized Loans | Agriculture Portfolio Segment [Member]
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Loans held for investment		$ 31,300,000
Performing | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	184.7
2019	238.8
2018	152.5
2017	100.4
2016	67.7
Prior	56.8
Revolving Loans Amortized Cost Basis	0
Total	800.9
Performing | Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	29.8
2019	39.4
2018	39.9
2017	17.0
2016	8.0
Prior	11.2
Revolving Loans Amortized Cost Basis	23.5
Total	168.8
Performing | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	136.4
Performing | Multi-family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	68.5
2019	76.7
2018	31.0
2017	30.4
2016	27.8
Prior	101.5
Revolving Loans Amortized Cost Basis	2.6
Total	338.5
Performing | Residential 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	191.0
2019	129.2
2018	84.3
2017	73.3
2016	86.2
Prior	309.0
Revolving Loans Amortized Cost Basis	0
Total	873.0
Performing | Consumer Home Equity and HELOC
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	8.7
2019	10.6
2018	10.5
2017	13.2
2016	5.7
Prior	16.4
Revolving Loans Amortized Cost Basis	347.8
Total	412.9
Nonperforming | Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0.4
2018	0.2
2017	0.1
2016	0.1
Prior	0.2
Revolving Loans Amortized Cost Basis	0
Total	1.0
Nonperforming | Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0.1
2018	0.1
2017	0.1
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0.2
Total	0.5
Nonperforming | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	1.7
Nonperforming | Multi-family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans Amortized Cost Basis	0
Total	0
Nonperforming | Residential 1-4 family
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0.4
2018	0
2017	0
2016	0
Prior	0.7
Revolving Loans Amortized Cost Basis	0
Total	1.1
Nonperforming | Consumer Home Equity and HELOC
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0.4
Revolving Loans Amortized Cost Basis	0.2
Total	0.6
Agriculture Portfolio Segment [Member] | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	1.7
Agriculture Portfolio Segment [Member] | Performing | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	1.7
Agriculture Portfolio Segment [Member] | Nonperforming | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	0
Commercial | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	65.8
Commercial | Performing | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	64.7
Commercial | Nonperforming | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	1.1
Total consumer loans | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	70.6
Total consumer loans | Performing | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	70.0
Total consumer loans | Nonperforming | Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
2020	$ 0.6