Amortized Cost Basis of Finance Receivables and Charge-offs by Credit Quality Indicator and Portfolio Class (Detail) - Financial Services - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	$ 3,416.6	$ 2,978.3
Financing Receivable Originated In Current Fiscal Year	1,203.9	4,662.3
Financed Receivables, By Origination Year, Current Fiscal Year	4,433.2	2,783.1
Financing Receivable, Originated One Year before Current Fiscal Year	2,547.1	1,802.9
Financing Receivable, Originated Two Years before Current Fiscal Year	1,612.0	988.0
Financing Receivable, Originated Three Years before Current Fiscal Year	854.6	378.5
Financed Receivables, By Origination Year, Prior	450.3	194.5
Finance Receivables, Total	14,517.7	13,787.6
Charge Offs Of Finance Receivables
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	0.0
Financing Receivable Originated In Current Fiscal Year	0.0
Financed Receivables, By Origination Year, Current Fiscal Year	1.8
Financing Receivable, Originated One Year before Current Fiscal Year	0.7
Financing Receivable, Originated Two Years before Current Fiscal Year	0.5
Financing Receivable, Originated Three Years before Current Fiscal Year	0.1
Financed Receivables, By Origination Year, Prior	0.3
Finance Receivables, Total	3.4
Dealer
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	3,416.6	2,978.3
Financing Receivable Originated In Current Fiscal Year	145.3	609.7
Financed Receivables, By Origination Year, Current Fiscal Year	588.7	348.6
Financing Receivable, Originated One Year before Current Fiscal Year	328.6	223.1
Financing Receivable, Originated Two Years before Current Fiscal Year	208.4	241.7
Financing Receivable, Originated Three Years before Current Fiscal Year	221.7	120.8
Financed Receivables, By Origination Year, Prior	208.6	121.8
Finance Receivables, Total	5,117.9	4,644.0
Dealer | Wholesale
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	3,251.9	2,772.1
Finance Receivables, Total	3,251.9	2,772.1
Dealer | Wholesale | Performing
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	3,244.4	2,766.0
Finance Receivables, Total	3,244.4	2,766.0
Dealer | Wholesale | Watch
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	7.5	6.1
Finance Receivables, Total	7.5	6.1
Dealer | Retail
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	164.7	206.2
Financing Receivable Originated In Current Fiscal Year	145.3	609.7
Financed Receivables, By Origination Year, Current Fiscal Year	588.7	348.6
Financing Receivable, Originated One Year before Current Fiscal Year	328.6	223.1
Financing Receivable, Originated Two Years before Current Fiscal Year	208.4	241.7
Financing Receivable, Originated Three Years before Current Fiscal Year	221.7	120.8
Financed Receivables, By Origination Year, Prior	208.6	121.8
Finance Receivables, Total	1,866.0	1,871.9
Dealer | Retail | Performing
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	164.7	206.2
Financing Receivable Originated In Current Fiscal Year	145.3	609.7
Financed Receivables, By Origination Year, Current Fiscal Year	588.7	348.6
Financing Receivable, Originated One Year before Current Fiscal Year	328.6	223.1
Financing Receivable, Originated Two Years before Current Fiscal Year	208.4	241.7
Financing Receivable, Originated Three Years before Current Fiscal Year	221.7	120.8
Financed Receivables, By Origination Year, Prior	208.1	121.1
Finance Receivables, Total	1,865.5	1,871.2
Dealer | Retail | At-risk
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Prior	0.5	0.7
Finance Receivables, Total	0.5	0.7
Customer Retail
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	1,058.6	4,052.6
Financed Receivables, By Origination Year, Current Fiscal Year	3,844.5	2,434.5
Financing Receivable, Originated One Year before Current Fiscal Year	2,218.5	1,579.8
Financing Receivable, Originated Two Years before Current Fiscal Year	1,403.6	746.3
Financing Receivable, Originated Three Years before Current Fiscal Year	632.9	257.7
Financed Receivables, By Origination Year, Prior	241.7	72.7
Finance Receivables, Total	9,399.8	9,143.6
Customer Retail | Fleet
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	938.6	3,572.2
Financed Receivables, By Origination Year, Current Fiscal Year	3,419.2	2,006.9
Financing Receivable, Originated One Year before Current Fiscal Year	1,849.9	1,327.1
Financing Receivable, Originated Two Years before Current Fiscal Year	1,194.4	624.3
Financing Receivable, Originated Three Years before Current Fiscal Year	537.4	211.7
Financed Receivables, By Origination Year, Prior	209.1	66.6
Finance Receivables, Total	8,148.6	7,808.8
Customer Retail | Fleet | Charge Offs Of Finance Receivables
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	0.0
Financing Receivable Originated In Current Fiscal Year	0.0
Financed Receivables, By Origination Year, Current Fiscal Year	1.5
Financing Receivable, Originated One Year before Current Fiscal Year	0.5
Financing Receivable, Originated Two Years before Current Fiscal Year	0.5
Financing Receivable, Originated Three Years before Current Fiscal Year	0.1
Financed Receivables, By Origination Year, Prior	0.2
Finance Receivables, Total	2.8
Customer Retail | Fleet | Performing
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	938.3	3,558.0
Financed Receivables, By Origination Year, Current Fiscal Year	3,397.9	1,981.9
Financing Receivable, Originated One Year before Current Fiscal Year	1,827.2	1,306.5
Financing Receivable, Originated Two Years before Current Fiscal Year	1,180.9	603.7
Financing Receivable, Originated Three Years before Current Fiscal Year	527.2	203.4
Financed Receivables, By Origination Year, Prior	204.6	65.6
Finance Receivables, Total	8,076.1	7,719.1
Customer Retail | Fleet | Watch
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	0.3	7.5
Financed Receivables, By Origination Year, Current Fiscal Year	2.9	7.3
Financing Receivable, Originated One Year before Current Fiscal Year	3.6	1.8
Financing Receivable, Originated Two Years before Current Fiscal Year	2.3	3.4
Financing Receivable, Originated Three Years before Current Fiscal Year	0.9	2.4
Financed Receivables, By Origination Year, Prior	1.2	0.5
Finance Receivables, Total	11.2	22.9
Customer Retail | Fleet | At-risk
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year		6.7
Financed Receivables, By Origination Year, Current Fiscal Year	18.4	17.7
Financing Receivable, Originated One Year before Current Fiscal Year	19.1	18.8
Financing Receivable, Originated Two Years before Current Fiscal Year	11.2	17.2
Financing Receivable, Originated Three Years before Current Fiscal Year	9.3	5.9
Financed Receivables, By Origination Year, Prior	3.3	0.5
Finance Receivables, Total	61.3	66.8
Customer Retail | Owner/Operator
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	120.0	480.4
Financed Receivables, By Origination Year, Current Fiscal Year	425.3	427.6
Financing Receivable, Originated One Year before Current Fiscal Year	368.6	252.7
Financing Receivable, Originated Two Years before Current Fiscal Year	209.2	122.0
Financing Receivable, Originated Three Years before Current Fiscal Year	95.5	46.0
Financed Receivables, By Origination Year, Prior	32.6	6.1
Finance Receivables, Total	1,251.2	1,334.8
Customer Retail | Owner/Operator | Charge Offs Of Finance Receivables
Financing Receivable, Recorded Investment [Line Items]
Financed Receivables, By Origination Year, Loans	0.0
Financing Receivable Originated In Current Fiscal Year	0.0
Financed Receivables, By Origination Year, Current Fiscal Year	0.3
Financing Receivable, Originated One Year before Current Fiscal Year	0.2
Financing Receivable, Originated Two Years before Current Fiscal Year	0.0
Financing Receivable, Originated Three Years before Current Fiscal Year	0.0
Financed Receivables, By Origination Year, Prior	0.1
Finance Receivables, Total	0.6
Customer Retail | Owner/Operator | Performing
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	119.7	478.2
Financed Receivables, By Origination Year, Current Fiscal Year	422.1	425.9
Financing Receivable, Originated One Year before Current Fiscal Year	366.5	251.2
Financing Receivable, Originated Two Years before Current Fiscal Year	207.2	120.9
Financing Receivable, Originated Three Years before Current Fiscal Year	94.8	45.3
Financed Receivables, By Origination Year, Prior	31.9	6.0
Finance Receivables, Total	1,242.2	1,327.5
Customer Retail | Owner/Operator | Watch
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	0.2	1.8
Financed Receivables, By Origination Year, Current Fiscal Year	2.4	0.9
Financing Receivable, Originated One Year before Current Fiscal Year	1.3	0.4
Financing Receivable, Originated Two Years before Current Fiscal Year	0.7	0.3
Financing Receivable, Originated Three Years before Current Fiscal Year	0.2
Financed Receivables, By Origination Year, Prior	0.2	0.1
Finance Receivables, Total	5.0	3.5
Customer Retail | Owner/Operator | At-risk
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable Originated In Current Fiscal Year	0.1	0.4
Financed Receivables, By Origination Year, Current Fiscal Year	0.8	0.8
Financing Receivable, Originated One Year before Current Fiscal Year	0.8	1.1
Financing Receivable, Originated Two Years before Current Fiscal Year	1.3	0.8
Financing Receivable, Originated Three Years before Current Fiscal Year	0.5	0.7
Financed Receivables, By Origination Year, Prior	0.5
Finance Receivables, Total	$ 4.0	$ 3.8