Revenue (Performance Obligations) (Details)	9 Months Ended
	Sep. 30, 2018
Motorcycles and Related Products | Licensing
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Sale Payment Terms	30 days
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	6 years
Financial Services | Financial Services Other income
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	6 years
Minimum | Motorcycles and Related Products | Parts & Accessories
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Sale Payment Terms	30 days
Minimum | Motorcycles and Related Products | Motorcycles
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Sale Payment Terms	30 days
Minimum | Motorcycles and Related Products | General Merchandise
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Sale Payment Terms	30 days
Maximum | Motorcycles and Related Products | Parts & Accessories
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Sale Payment Terms	120 days
Maximum | Motorcycles and Related Products | Motorcycles
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Sale Payment Terms	120 days
Maximum | Motorcycles and Related Products | General Merchandise
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Sale Payment Terms	120 days