Loans Held for Investment - Schedule of Recorded Credit Quality Indicator (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Commitments to purchase or sell	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Proceeds from sale of loans held-for-investment	0.0	0.0	0.0	0.0
Less loans charged-off	(16.3)	(14.1)	(27.3)	(23.0)
Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	9,054.5		9,054.5		$ 8,869.2
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	623.2		623.2		1,337.6
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,385.6		1,385.6		2,085.9
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	2,008.7		2,008.7		1,675.0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	1,555.9		1,555.9		1,215.4
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	1,184.8		1,184.8		774.1
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	2,194.6		2,194.6		1,706.1
Financing Receivable, Excluding Accrued Interest, Revolving	51.7		51.7		47.0
Less loans charged-off			(5.7)		(7.6)
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	50.0		50.0		28.1
Commercial | Year One, Originated, Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		(1.7)
Commercial | Year Two, Originated, Fiscal Year Before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(5.6)		(0.3)
Commercial | Year Three, Originated, Two Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		(1.7)
Commercial | Year Four, Originated, Three Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		(2.6)
Commercial | Year Five, Originated, Four Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Commercial | Originated, More than Five Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.1)		(1.3)
Commercial | Revolving
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Commercial | Revolving, Converted to Term
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Residential
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	2,246.4		2,246.4		2,244.3
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	8.4		8.4		45.8
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	61.4		61.4		359.0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	418.7		418.7		522.5
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	508.0		508.0		501.7
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	473.2		473.2		89.2
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	284.7		284.7		222.2
Financing Receivable, Excluding Accrued Interest, Revolving	481.6		481.6		471.8
Less loans charged-off			(0.6)		(0.6)
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	10.4		10.4		32.1
Residential | Year One, Originated, Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		(0.3)
Residential | Year Two, Originated, Fiscal Year Before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.2)		0.0
Residential | Year Three, Originated, Two Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.1)		(0.1)
Residential | Year Four, Originated, Three Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.1)		(0.1)
Residential | Year Five, Originated, Four Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.1)		0.0
Residential | Originated, More than Five Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.1)		(0.1)
Residential | Revolving
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Residential | Revolving, Converted to Term
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	1,519.9		1,519.9		1,826.5
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	210.1		210.1		501.2
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	373.3		373.3		758.9
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	617.5		617.5		356.9
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	121.8		121.8		36.9
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	20.2		20.2		16.8
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	27.6		27.6		36.8
Financing Receivable, Excluding Accrued Interest, Revolving	121.1		121.1		104.4
Less loans charged-off			(7.0)		(10.3)
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	28.3		28.3		14.6
Total construction loans | Year One, Originated, Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Total construction loans | Year Two, Originated, Fiscal Year Before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Total construction loans | Year Three, Originated, Two Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(6.9)		(0.1)
Total construction loans | Year Four, Originated, Three Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Total construction loans | Year Five, Originated, Four Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.1)		(0.6)
Total construction loans | Originated, More than Five Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Total construction loans | Revolving
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Total construction loans | Revolving, Converted to Term
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		(9.6)
Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	723.5		723.5		716.8
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	77.6		77.6		96.9
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	81.1		81.1		154.0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	141.7		141.7		133.3
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	131.6		131.6		98.0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	90.7		90.7		58.6
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	174.6		174.6		136.7
Financing Receivable, Excluding Accrued Interest, Revolving	26.2		26.2		32.3
Less loans charged-off			0.0		0.0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		7.0
Agricultural | Year One, Originated, Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Year Two, Originated, Fiscal Year Before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Year Three, Originated, Two Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Year Four, Originated, Three Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Year Five, Originated, Four Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Originated, More than Five Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Revolving
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Revolving, Converted to Term
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Total real estate
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off	(10.1)	(10.0)	(13.3)	(14.8)
Indirect consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	733.7		733.7		740.9
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	130.4		130.4		195.3
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	164.6		164.6		265.6
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	217.3		217.3		116.0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	93.9		93.9		81.5
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	63.8		63.8		33.1
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	63.7		63.7		49.4
Financing Receivable, Excluding Accrued Interest, Revolving	0.0		0.0		0.0
Less loans charged-off			(4.5)		(7.3)
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		0.0
Indirect consumer | Year One, Originated, Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		(0.5)
Indirect consumer | Year Two, Originated, Fiscal Year Before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.7)		(3.2)
Indirect consumer | Year Three, Originated, Two Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(2.3)		(1.8)
Indirect consumer | Year Four, Originated, Three Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.6)		(0.8)
Indirect consumer | Year Five, Originated, Four Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.2)		(0.3)
Indirect consumer | Originated, More than Five Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.7)		(0.7)
Indirect consumer | Revolving
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Indirect consumer | Revolving, Converted to Term
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Direct consumer
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	139.0		139.0		141.6
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	27.3		27.3		44.6
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	34.1		34.1		33.0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	25.5		25.5		18.6
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	13.9		13.9		9.4
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	6.6		6.6		3.6
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	7.2		7.2		6.0
Financing Receivable, Excluding Accrued Interest, Revolving	24.3		24.3		26.2
Less loans charged-off			(1.9)		(4.1)
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.1		0.1		0.2
Direct consumer | Year One, Originated, Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.1)		(0.2)
Direct consumer | Year Two, Originated, Fiscal Year Before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.3)		(0.5)
Direct consumer | Year Three, Originated, Two Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.5)		(0.2)
Direct consumer | Year Four, Originated, Three Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.2)		(0.4)
Direct consumer | Year Five, Originated, Four Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		(0.1)
Direct consumer | Originated, More than Five Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.8)		(2.6)
Direct consumer | Revolving
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		(0.1)
Direct consumer | Revolving, Converted to Term
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Credit card
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	76.1		76.1		76.5
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Revolving	76.1		76.1		76.5
Less loans charged-off			(1.4)		(2.6)
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		0.0
Credit card | Year One, Originated, Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Credit card | Year Two, Originated, Fiscal Year Before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Credit card | Year Three, Originated, Two Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Credit card | Year Four, Originated, Three Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Credit card | Year Five, Originated, Four Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Credit card | Originated, More than Five Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Credit card | Revolving
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(1.4)		(2.6)
Credit card | Revolving, Converted to Term
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Total consumer loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off	(4.0)	(3.3)	(7.8)	(6.7)
Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	3,052.9		3,052.9		2,906.8
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	352.2		352.2		508.0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	440.0		440.0		533.3
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	458.8		458.8		407.0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	364.8		364.8		225.2
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	200.5		200.5		111.2
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	321.2		321.2		277.9
Financing Receivable, Excluding Accrued Interest, Revolving	912.0		912.0		836.0
Less loans charged-off	(2.2)	(0.8)	(6.2)	(1.5)	(3.4)
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	3.4		3.4		8.2
Commercial | Year One, Originated, Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		(0.2)
Commercial | Year Two, Originated, Fiscal Year Before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.8)		(0.4)
Commercial | Year Three, Originated, Two Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.8)		(0.5)
Commercial | Year Four, Originated, Three Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.2)		(0.5)
Commercial | Year Five, Originated, Four Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(0.1)		(0.2)
Commercial | Originated, More than Five Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		(0.1)
Commercial | Revolving
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(1.4)		(1.4)
Commercial | Revolving, Converted to Term
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			(2.9)		(0.1)
Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	698.2		698.2		769.4
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	117.6		117.6		152.1
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	88.3		88.3		58.8
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	46.6		46.6		34.8
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	22.4		22.4		23.3
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	19.1		19.1		35.0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	11.8		11.8		9.5
Financing Receivable, Excluding Accrued Interest, Revolving	392.3		392.3		449.4
Less loans charged-off	0.0	$ 0.0	0.0	$ 0.0	0.0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.1		0.1		6.5
Agricultural | Year One, Originated, Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Year Two, Originated, Fiscal Year Before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Year Three, Originated, Two Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Year Four, Originated, Three Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Year Five, Originated, Four Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Originated, More than Five Years before Current Fiscal Year
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Revolving
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Agricultural | Revolving, Converted to Term
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Less loans charged-off			0.0		0.0
Pass | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	8,806.6		8,806.6		8,596.9
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	599.5		599.5		1,268.0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,360.8		1,360.8		2,065.0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	1,985.1		1,985.1		1,612.2
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	1,482.6		1,482.6		1,200.1
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	1,171.9		1,171.9		716.5
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	2,114.2		2,114.2		1,660.5
Financing Receivable, Excluding Accrued Interest, Revolving	51.6		51.6		46.5
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	40.9		40.9		28.1
Pass | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	1,498.5		1,498.5		1,768.0
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	206.3		206.3		493.7
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	369.0		369.0		735.3
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	604.8		604.8		331.2
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	121.8		121.8		36.7
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	20.2		20.2		16.8
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	27.0		27.0		36.2
Financing Receivable, Excluding Accrued Interest, Revolving	121.1		121.1		104.4
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	28.3		28.3		13.7
Pass | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	659.7		659.7		649.4
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	64.4		64.4		86.2
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	70.1		70.1		123.7
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	117.6		117.6		126.2
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	124.7		124.7		93.5
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	84.3		84.3		56.7
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	172.4		172.4		124.3
Financing Receivable, Excluding Accrued Interest, Revolving	26.2		26.2		31.8
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		7.0
Pass | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	2,898.0		2,898.0		2,745.7
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	320.3		320.3		481.6
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	424.5		424.5		507.7
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	439.9		439.9		389.8
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	356.4		356.4		215.1
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	190.8		190.8		108.7
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	316.9		316.9		272.9
Financing Receivable, Excluding Accrued Interest, Revolving	847.3		847.3		762.3
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	1.9		1.9		7.6
Pass | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	586.9		586.9		656.0
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	64.7		64.7		105.7
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	60.1		60.1		57.7
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	45.7		45.7		31.6
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	21.7		21.7		22.4
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	18.4		18.4		6.1
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	11.6		11.6		7.2
Financing Receivable, Excluding Accrued Interest, Revolving	364.6		364.6		421.9
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.1		0.1		3.4
Other Assets Especially Mentioned | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	82.6		82.6		113.7
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	6.2		6.2		4.2
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	6.6		6.6		9.1
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	19.2		19.2		42.6
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	17.8		17.8		12.9
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	3.4		3.4		27.5
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	29.3		29.3		17.1
Financing Receivable, Excluding Accrued Interest, Revolving	0.1		0.1		0.3
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		0.0
Other Assets Especially Mentioned | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	9.5		9.5		9.5
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	1.9		1.9		0.5
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	0.9		0.9		6.6
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	6.5		6.5		1.3
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0.2		0.2		0.2
Financing Receivable, Excluding Accrued Interest, Revolving	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		0.9
Other Assets Especially Mentioned | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	21.7		21.7		30.8
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	1.1		1.1		2.6
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	6.6		6.6		9.5
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	4.5		4.5		3.5
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	3.2		3.2		1.9
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	5.0		5.0		1.5
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	1.3		1.3		11.3
Financing Receivable, Excluding Accrued Interest, Revolving	0.0		0.0		0.5
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		0.0
Other Assets Especially Mentioned | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	39.4		39.4		39.5
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	1.4		1.4		7.3
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	7.9		7.9		4.7
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	8.6		8.6		6.6
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	2.9		2.9		3.1
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	1.2		1.2		0.9
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	1.3		1.3		1.9
Financing Receivable, Excluding Accrued Interest, Revolving	16.1		16.1		14.8
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		0.2
Other Assets Especially Mentioned | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	9.1		9.1		16.4
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0.4		0.4		2.6
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	3.4		3.4		0.8
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0.7		0.7		0.5
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0.1		0.1		0.2
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0.1		0.1		0.1
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0.2		0.2		0.1
Financing Receivable, Excluding Accrued Interest, Revolving	4.2		4.2		9.0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		3.1
Substandard | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	165.3		165.3		157.3
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	17.5		17.5		65.4
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	18.2		18.2		11.8
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	4.4		4.4		18.9
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	55.5		55.5		2.4
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	9.5		9.5		30.1
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	51.1		51.1		28.5
Financing Receivable, Excluding Accrued Interest, Revolving	0.0		0.0		0.2
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	9.1		9.1		0.0
Substandard | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	11.9		11.9		36.0
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	1.9		1.9		7.0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	3.4		3.4		4.0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	6.2		6.2		24.4
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0.0		0.0		0.2
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0.4		0.4		0.4
Financing Receivable, Excluding Accrued Interest, Revolving	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		0.0
Substandard | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	42.1		42.1		36.6
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	12.1		12.1		8.1
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	4.4		4.4		20.8
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	19.6		19.6		3.6
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	3.7		3.7		2.6
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	1.4		1.4		0.4
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0.9		0.9		1.1
Financing Receivable, Excluding Accrued Interest, Revolving	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		0.0
Substandard | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	70.0		70.0		115.2
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	29.3		29.3		15.8
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	5.9		5.9		19.6
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	9.4		9.4		9.0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	4.9		4.9		7.0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	8.5		8.5		1.6
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	3.0		3.0		3.0
Financing Receivable, Excluding Accrued Interest, Revolving	7.5		7.5		58.8
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	1.5		1.5		0.4
Substandard | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	101.7		101.7		97.0
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	52.5		52.5		43.8
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	24.8		24.8		0.3
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0.2		0.2		2.7
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0.1		0.1		0.7
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0.6		0.6		28.8
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0.0		0.0		2.2
Financing Receivable, Excluding Accrued Interest, Revolving	23.5		23.5		18.5
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		0.0
Doubtful | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total					1.3
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year					0.0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year					0.0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year					1.3
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year					0.0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year					0.0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year					0.0
Financing Receivable, Excluding Accrued Interest, Revolving					0.0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan					0.0
Doubtful | Total construction loans
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total					13.0
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year					0.0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year					13.0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year					0.0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year					0.0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year					0.0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year					0.0
Financing Receivable, Excluding Accrued Interest, Revolving					0.0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan					0.0
Doubtful | Commercial
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	45.5		45.5		6.4
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	1.2		1.2		3.3
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	1.7		1.7		1.3
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0.9		0.9		1.6
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0.6		0.6		0.0
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0.0		0.0		0.0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0.0		0.0		0.1
Financing Receivable, Excluding Accrued Interest, Revolving	41.1		41.1		0.1
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	0.0		0.0		$ 0.0
Doubtful | Agricultural
Loans and Leases Receivable Recorded Investment, Criticized Loans [Line Items]
Total	0.5		0.5
Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year	0.0		0.0
Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year	0.0		0.0
Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year	0.0		0.0
Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year	0.5		0.5
Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year	0.0		0.0
Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year	0.0		0.0
Financing Receivable, Excluding Accrued Interest, Revolving	0.0		0.0
Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan	$ 0.0		$ 0.0