Amortized Cost Basis of Finance Receivables and Charge-offs by Credit Quality Indicator and Portfolio Class (Detail) - Financial Services - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	$ 3,816.1	$ 2,978.3
Financing Receivable Originated In Current Fiscal Year	2,882.9	4,662.3
Financing Receivable, Originated One Year before Current Fiscal Year	4,176.7	2,783.1
Financing Receivable, Originated Two Years before Current Fiscal Year	2,314.9	1,802.9
Financing Receivable, Originated Three Years before Current Fiscal Year	1,393.3	988.0
Financing Receivable, Originated Four Years before Current Fiscal Year	719.1	378.5
Financed Receivables, By Origination Year, Prior	346.8	194.5
Finance Receivables, Total	15,649.8	13,787.6
Charge Offs Of Finance Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated One Year before Current Fiscal Year	3.1
Financing Receivable, Originated Two Years before Current Fiscal Year	3.8
Financing Receivable, Originated Three Years before Current Fiscal Year	1.7
Financing Receivable, Originated Four Years before Current Fiscal Year	0.2
Financed Receivables, By Origination Year, Prior	0.6
Finance Receivables, Total	9.4
Dealer
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	3,816.1	2,978.3
Financing Receivable Originated In Current Fiscal Year	345.0	609.7
Financing Receivable, Originated One Year before Current Fiscal Year	565.8	348.6
Financing Receivable, Originated Two Years before Current Fiscal Year	312.4	223.1
Financing Receivable, Originated Three Years before Current Fiscal Year	194.5	241.7
Financing Receivable, Originated Four Years before Current Fiscal Year	201.4	120.8
Financed Receivables, By Origination Year, Prior	177.5	121.8
Finance Receivables, Total	5,612.7	4,644.0
Dealer | Wholesale
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	3,650.9	2,772.1
Finance Receivables, Total	3,650.9	2,772.1
Dealer | Wholesale | Performing
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	3,649.4	2,766.0
Finance Receivables, Total	3,649.4	2,766.0
Dealer | Wholesale | Watch
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	1.5	6.1
Finance Receivables, Total	1.5	6.1
Dealer | Retail
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	165.2	206.2
Financing Receivable Originated In Current Fiscal Year	345.0	609.7
Financing Receivable, Originated One Year before Current Fiscal Year	565.8	348.6
Financing Receivable, Originated Two Years before Current Fiscal Year	312.4	223.1
Financing Receivable, Originated Three Years before Current Fiscal Year	194.5	241.7
Financing Receivable, Originated Four Years before Current Fiscal Year	201.4	120.8
Financed Receivables, By Origination Year, Prior	177.5	121.8
Finance Receivables, Total	1,961.8	1,871.9
Dealer | Retail | Performing
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	165.2	206.2
Financing Receivable Originated In Current Fiscal Year	345.0	609.7
Financing Receivable, Originated One Year before Current Fiscal Year	565.8	348.6
Financing Receivable, Originated Two Years before Current Fiscal Year	312.4	223.1
Financing Receivable, Originated Three Years before Current Fiscal Year	194.5	241.7
Financing Receivable, Originated Four Years before Current Fiscal Year	201.4	120.8
Financed Receivables, By Origination Year, Prior	177.5	121.1
Finance Receivables, Total	1,961.8	1,871.2
Dealer | Retail | At-risk
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Prior		0.7
Finance Receivables, Total		0.7
Customer Retail
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	2,537.9	4,052.6
Financing Receivable, Originated One Year before Current Fiscal Year	3,610.9	2,434.5
Financing Receivable, Originated Two Years before Current Fiscal Year	2,002.5	1,579.8
Financing Receivable, Originated Three Years before Current Fiscal Year	1,198.8	746.3
Financing Receivable, Originated Four Years before Current Fiscal Year	517.7	257.7
Financed Receivables, By Origination Year, Prior	169.3	72.7
Finance Receivables, Total	10,037.1	9,143.6
Customer Retail | Fleet
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	2,296.9	3,572.2
Financing Receivable, Originated One Year before Current Fiscal Year	3,213.2	2,006.9
Financing Receivable, Originated Two Years before Current Fiscal Year	1,672.2	1,327.1
Financing Receivable, Originated Three Years before Current Fiscal Year	1,014.9	624.3
Financing Receivable, Originated Four Years before Current Fiscal Year	437.5	211.7
Financed Receivables, By Origination Year, Prior	147.7	66.6
Finance Receivables, Total	8,782.4	7,808.8
Customer Retail | Fleet | Charge Offs Of Finance Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated One Year before Current Fiscal Year	2.5
Financing Receivable, Originated Two Years before Current Fiscal Year	2.8
Financing Receivable, Originated Three Years before Current Fiscal Year	1.5
Financing Receivable, Originated Four Years before Current Fiscal Year	0.2
Financed Receivables, By Origination Year, Prior	0.4
Finance Receivables, Total	7.4
Customer Retail | Fleet | Performing
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	2,287.0	3,558.0
Financing Receivable, Originated One Year before Current Fiscal Year	3,182.6	1,981.9
Financing Receivable, Originated Two Years before Current Fiscal Year	1,653.5	1,306.5
Financing Receivable, Originated Three Years before Current Fiscal Year	1,007.4	603.7
Financing Receivable, Originated Four Years before Current Fiscal Year	429.6	203.4
Financed Receivables, By Origination Year, Prior	143.6	65.6
Finance Receivables, Total	8,703.7	7,719.1
Customer Retail | Fleet | Watch
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	3.5	7.5
Financing Receivable, Originated One Year before Current Fiscal Year	9.8	7.3
Financing Receivable, Originated Two Years before Current Fiscal Year	5.1	1.8
Financing Receivable, Originated Three Years before Current Fiscal Year	2.0	3.4
Financing Receivable, Originated Four Years before Current Fiscal Year	1.1	2.4
Financed Receivables, By Origination Year, Prior	1.5	0.5
Finance Receivables, Total	23.0	22.9
Customer Retail | Fleet | At-risk
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	6.4	6.7
Financing Receivable, Originated One Year before Current Fiscal Year	20.8	17.7
Financing Receivable, Originated Two Years before Current Fiscal Year	13.6	18.8
Financing Receivable, Originated Three Years before Current Fiscal Year	5.5	17.2
Financing Receivable, Originated Four Years before Current Fiscal Year	6.8	5.9
Financed Receivables, By Origination Year, Prior	2.6	0.5
Finance Receivables, Total	55.7	66.8
Customer Retail | Owner/Operator
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	241.0	480.4
Financing Receivable, Originated One Year before Current Fiscal Year	397.7	427.6
Financing Receivable, Originated Two Years before Current Fiscal Year	330.3	252.7
Financing Receivable, Originated Three Years before Current Fiscal Year	183.9	122.0
Financing Receivable, Originated Four Years before Current Fiscal Year	80.2	46.0
Financed Receivables, By Origination Year, Prior	21.6	6.1
Finance Receivables, Total	1,254.7	1,334.8
Customer Retail | Owner/Operator | Charge Offs Of Finance Receivables
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Originated One Year before Current Fiscal Year	0.6
Financing Receivable, Originated Two Years before Current Fiscal Year	1.0
Financing Receivable, Originated Three Years before Current Fiscal Year	0.2
Financed Receivables, By Origination Year, Prior	0.2
Finance Receivables, Total	2.0
Customer Retail | Owner/Operator | Performing
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	240.4	478.2
Financing Receivable, Originated One Year before Current Fiscal Year	393.6	425.9
Financing Receivable, Originated Two Years before Current Fiscal Year	327.4	251.2
Financing Receivable, Originated Three Years before Current Fiscal Year	181.7	120.9
Financing Receivable, Originated Four Years before Current Fiscal Year	79.5	45.3
Financed Receivables, By Origination Year, Prior	21.3	6.0
Finance Receivables, Total	1,243.9	1,327.5
Customer Retail | Owner/Operator | Watch
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	0.3	1.8
Financing Receivable, Originated One Year before Current Fiscal Year	2.1	0.9
Financing Receivable, Originated Two Years before Current Fiscal Year	1.6	0.4
Financing Receivable, Originated Three Years before Current Fiscal Year	0.8	0.3
Financing Receivable, Originated Four Years before Current Fiscal Year	0.2
Financed Receivables, By Origination Year, Prior	0.1	0.1
Finance Receivables, Total	5.1	3.5
Customer Retail | Owner/Operator | At-risk
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	0.3	0.4
Financing Receivable, Originated One Year before Current Fiscal Year	2.0	0.8
Financing Receivable, Originated Two Years before Current Fiscal Year	1.3	1.1
Financing Receivable, Originated Three Years before Current Fiscal Year	1.4	0.8
Financing Receivable, Originated Four Years before Current Fiscal Year	0.5	0.7
Financed Receivables, By Origination Year, Prior	0.2
Finance Receivables, Total	$ 5.7	$ 3.8