Asset-Backed Financing - Additional Information (Details)	1 Months Ended	3 Months Ended									12 Months Ended
	Jun. 30, 2018 CAD ($)	Dec. 31, 2019 USD ($)	Sep. 29, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jul. 01, 2018 USD ($)	Apr. 01, 2018 USD ($)	Jun. 26, 2016 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	May 31, 2019 USD ($)	Nov. 30, 2018 USD ($)
Variable Interest Entity [Line Items]
Proceeds from securitization debt											$ 1,021,453,000	$ 0	$ 0
Financial Services interest expense											210,438,000	193,187,000	$ 180,193,000
Servicing and ancillary fees											600,000	1,100,000
Asset Backed Securitization 1 | U.S. Line of Credit
Variable Interest Entity [Line Items]
Transfers on finance receivables											539,100,000
Asset Backed Securitization 2 | U.S. Line of Credit
Variable Interest Entity [Line Items]
Transfers on finance receivables											580,200,000
Variable Interest Entity, Primary Beneficiary | Secured Debt
Variable Interest Entity [Line Items]
Financial Services interest expense											$ 13,300,000	$ 3,200,000
Weighted average interest rate at date of issuance		2.36%				1.67%					2.36%	1.67%
Variable Interest Entity, Primary Beneficiary | Secured Debt | Asset-Backed U.S. Commercial Paper Conduit Facility VIE, Facility 2 | U.S. Line of Credit
Variable Interest Entity [Line Items]
Revolving credit facility addition to incremental borrowings														$ 300,000,000.0
Line of credit, maximum borrowing capacity															$ 300,000,000.0
Variable Interest Entity, Primary Beneficiary | Secured Debt | Asset-Backed U.S. Commercial Paper Conduit Facility VIE, Facility 1 | U.S. Line of Credit
Variable Interest Entity [Line Items]
Line of credit, maximum borrowing capacity															$ 600,000,000.0
Variable Interest Entity, Primary Beneficiary | Secured Debt | Asset-Backed U.S. Commercial Paper Conduit Facility VIE | Line of Credit
Variable Interest Entity [Line Items]
Financial Services interest expense											$ 18,500,000	$ 10,900,000
Weighted average interest rate at date of issuance		2.63%				3.26%					2.63%	3.26%
Variable Interest Entity, Primary Beneficiary | Secured Debt | Asset-Backed U.S. Commercial Paper Conduit Facility VIE | U.S. Line of Credit
Variable Interest Entity [Line Items]
Transfers on finance receivables		$ 0	$ 174,400,000	$ 0	$ 0	$ 400,200,000	$ 0	$ 59,100,000	$ 32,900,000		$ 174,400,000	$ 492,200,000
Debt instrument, term											5 years
Amount transferred, face amount		0	154,600,000	0	0	$ 356,800,000	0	53,300,000	29,300,000		$ 154,600,000	439,400,000
Variable Interest Entity, Primary Beneficiary | Secured Debt | Asset-backed Securities, Securitized Loans and Receivables | Asset Backed Securitization 1
Variable Interest Entity [Line Items]
Secured notes issued		500,000,000.0									500,000,000.0
Proceeds from securitization debt											498,700,000	0
Variable Interest Entity, Primary Beneficiary | Secured Debt | Asset-backed Securities, Securitized Loans and Receivables | Asset Backed Securitization 2
Variable Interest Entity [Line Items]
Secured notes issued		525,000,000.0									525,000,000.0
Proceeds from securitization debt											522,600,000	0
Unconsolidated VIEs:
Variable Interest Entity [Line Items]
Principal balance of finance receivable										$ 301,800,000
Gain on sale of finance receivable										9,300,000
Cash proceeds from sale of financial asset										$ 312,600,000
Unpaid principal balance of the retail motorcycle finance receivables		$ 35,200,000									35,200,000
Unconsolidated VIEs: | Secured Debt | Asset-backed Canadian commercial paper conduit facility
Variable Interest Entity [Line Items]
Financial Services interest expense											$ 3,600,000	$ 3,800,000
Weighted average interest rate at date of issuance		2.68%				2.68%					2.68%	2.68%
Unconsolidated VIEs: | Secured Debt | Asset-backed Canadian commercial paper conduit facility | Foreign Line of Credit
Variable Interest Entity [Line Items]
Transfers on finance receivables		$ 0	0	28,200,000	0	$ 39,000,000	0	38,900,000	7,600,000		$ 28,200,000	$ 85,500,000
Line of credit, maximum borrowing capacity	$ 220,000,000.0
Debt instrument, term	5 years
Amount transferred, face amount		0	$ 0	$ 23,400,000	$ 0	$ 32,200,000	$ 0	$ 32,200,000	$ 6,200,000		23,400,000	$ 70,600,000
VIE, maximum loss exposure, amount		$ 123,200,000									$ 123,200,000