Amortized Cost Basis of Finance Receivables by Credit Quality Indicator and Portfolio Class (Detail) - Financial Services - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Recorded Investment [Line Items]
Financing Receivables, By Origination Year, Loans	$ 2,978.3	$ 2,067.7
Financing Receivable Originated In Current Fiscal Year	4,662.3	3,914.5
Financed Receivables, By Origination Year, Current Fiscal Year	2,783.1	2,639.0
Financing Receivable, Originated One Year before Current Fiscal Year	1,802.9	1,808.4
Financing Receivable, Originated Two Years before Current Fiscal Year	988.0	923.3
Financing Receivable, Originated Three Years before Current Fiscal Year	378.5	382.8
Financed Receivables, By Origination Year, Prior	194.5	175.4
Finance Receivables, Total	13,787.6	11,911.1
Dealer
Financing Receivable, Recorded Investment [Line Items]
Financing Receivables, By Origination Year, Loans	2,978.3	2,067.7
Financing Receivable Originated In Current Fiscal Year	609.7	441.4
Financed Receivables, By Origination Year, Current Fiscal Year	348.6	319.0
Financing Receivable, Originated One Year before Current Fiscal Year	223.1	320.8
Financing Receivable, Originated Two Years before Current Fiscal Year	241.7	180.6
Financing Receivable, Originated Three Years before Current Fiscal Year	120.8	119.3
Financed Receivables, By Origination Year, Prior	121.8	98.0
Finance Receivables, Total	4,644.0	3,546.8
Dealer | Wholesale
Financing Receivable, Recorded Investment [Line Items]
Financing Receivables, By Origination Year, Loans	2,772.1	1,865.8
Finance Receivables, Total	2,772.1	1,865.8
Dealer | Wholesale | Performing
Financing Receivable, Recorded Investment [Line Items]
Financing Receivables, By Origination Year, Loans	2,766.0	1,859.7
Finance Receivables, Total	2,766.0	1,859.7
Dealer | Wholesale | Watch
Financing Receivable, Recorded Investment [Line Items]
Financing Receivables, By Origination Year, Loans	6.1	6.1
Finance Receivables, Total	6.1	6.1
Dealer | Retail
Financing Receivable, Recorded Investment [Line Items]
Financing Receivables, By Origination Year, Loans	206.2	201.9
Financing Receivable Originated In Current Fiscal Year	609.7	441.4
Financed Receivables, By Origination Year, Current Fiscal Year	348.6	319.0
Financing Receivable, Originated One Year before Current Fiscal Year	223.1	320.8
Financing Receivable, Originated Two Years before Current Fiscal Year	241.7	180.6
Financing Receivable, Originated Three Years before Current Fiscal Year	120.8	119.3
Financed Receivables, By Origination Year, Prior	121.8	98.0
Finance Receivables, Total	1,871.9	1,681.0
Dealer | Retail | Performing
Financing Receivable, Recorded Investment [Line Items]
Financing Receivables, By Origination Year, Loans	206.2	201.9
Financing Receivable Originated In Current Fiscal Year	609.7	434.4
Financed Receivables, By Origination Year, Current Fiscal Year	348.6	315.4
Financing Receivable, Originated One Year before Current Fiscal Year	223.1	311.7
Financing Receivable, Originated Two Years before Current Fiscal Year	241.7	176.0
Financing Receivable, Originated Three Years before Current Fiscal Year	120.8	118.2
Financed Receivables, By Origination Year, Prior	121.1	96.9
Finance Receivables, Total	1,871.2	1,654.5
Dealer | Retail | Watch
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year		7.0
Financed Receivables, By Origination Year, Current Fiscal Year		3.6
Financing Receivable, Originated One Year before Current Fiscal Year		9.1
Financing Receivable, Originated Two Years before Current Fiscal Year		4.6
Financing Receivable, Originated Three Years before Current Fiscal Year		1.1
Finance Receivables, Total		25.4
Dealer | Retail | At-risk
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Prior	0.7	1.1
Finance Receivables, Total	0.7	1.1
Customer Retail
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	4,052.6	3,473.1
Financed Receivables, By Origination Year, Current Fiscal Year	2,434.5	2,320.0
Financing Receivable, Originated One Year before Current Fiscal Year	1,579.8	1,487.6
Financing Receivable, Originated Two Years before Current Fiscal Year	746.3	742.7
Financing Receivable, Originated Three Years before Current Fiscal Year	257.7	263.5
Financed Receivables, By Origination Year, Prior	72.7	77.4
Finance Receivables, Total	9,143.6	8,364.3
Customer Retail | Fleet
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	3,572.2	2,860.3
Financed Receivables, By Origination Year, Current Fiscal Year	2,006.9	1,928.3
Financing Receivable, Originated One Year before Current Fiscal Year	1,327.1	1,257.3
Financing Receivable, Originated Two Years before Current Fiscal Year	624.3	624.3
Financing Receivable, Originated Three Years before Current Fiscal Year	211.7	224.3
Financed Receivables, By Origination Year, Prior	66.6	67.1
Finance Receivables, Total	7,808.8	6,961.6
Customer Retail | Fleet | Performing
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	3,558.0	2,851.7
Financed Receivables, By Origination Year, Current Fiscal Year	1,981.9	1,913.3
Financing Receivable, Originated One Year before Current Fiscal Year	1,306.5	1,227.0
Financing Receivable, Originated Two Years before Current Fiscal Year	603.7	608.4
Financing Receivable, Originated Three Years before Current Fiscal Year	203.4	220.4
Financed Receivables, By Origination Year, Prior	65.6	66.5
Finance Receivables, Total	7,719.1	6,887.3
Customer Retail | Fleet | Watch
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	7.5	2.6
Financed Receivables, By Origination Year, Current Fiscal Year	7.3	6.5
Financing Receivable, Originated One Year before Current Fiscal Year	1.8	4.3
Financing Receivable, Originated Two Years before Current Fiscal Year	3.4	5.3
Financing Receivable, Originated Three Years before Current Fiscal Year	2.4	0.6
Financed Receivables, By Origination Year, Prior	0.5	0.2
Finance Receivables, Total	22.9	19.5
Customer Retail | Fleet | At-risk
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	6.7	6.0
Financed Receivables, By Origination Year, Current Fiscal Year	17.7	8.5
Financing Receivable, Originated One Year before Current Fiscal Year	18.8	26.0
Financing Receivable, Originated Two Years before Current Fiscal Year	17.2	10.6
Financing Receivable, Originated Three Years before Current Fiscal Year	5.9	3.3
Financed Receivables, By Origination Year, Prior	0.5	0.4
Finance Receivables, Total	66.8	54.8
Customer Retail | Owner/Operator
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	480.4	612.8
Financed Receivables, By Origination Year, Current Fiscal Year	427.6	391.7
Financing Receivable, Originated One Year before Current Fiscal Year	252.7	230.3
Financing Receivable, Originated Two Years before Current Fiscal Year	122.0	118.4
Financing Receivable, Originated Three Years before Current Fiscal Year	46.0	39.2
Financed Receivables, By Origination Year, Prior	6.1	10.3
Finance Receivables, Total	1,334.8	1,402.7
Customer Retail | Owner/Operator | Performing
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	478.2	611.9
Financed Receivables, By Origination Year, Current Fiscal Year	425.9	389.9
Financing Receivable, Originated One Year before Current Fiscal Year	251.2	228.1
Financing Receivable, Originated Two Years before Current Fiscal Year	120.9	116.0
Financing Receivable, Originated Three Years before Current Fiscal Year	45.3	38.6
Financed Receivables, By Origination Year, Prior	6.0	10.1
Finance Receivables, Total	1,327.5	1,394.6
Customer Retail | Owner/Operator | Watch
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	1.8	0.7
Financed Receivables, By Origination Year, Current Fiscal Year	0.9	0.5
Financing Receivable, Originated One Year before Current Fiscal Year	0.4	0.7
Financing Receivable, Originated Two Years before Current Fiscal Year	0.3	0.4
Financing Receivable, Originated Three Years before Current Fiscal Year		0.1
Financed Receivables, By Origination Year, Prior	0.1
Finance Receivables, Total	3.5	2.4
Customer Retail | Owner/Operator | At-risk
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	0.4	0.2
Financed Receivables, By Origination Year, Current Fiscal Year	0.8	1.3
Financing Receivable, Originated One Year before Current Fiscal Year	1.1	1.5
Financing Receivable, Originated Two Years before Current Fiscal Year	0.8	2.0
Financing Receivable, Originated Three Years before Current Fiscal Year	0.7	0.5
Financed Receivables, By Origination Year, Prior		0.2
Finance Receivables, Total	$ 3.8	$ 5.7