Summary of Significant Accounting Policies (Product Warranty and Recall) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Product Warranty Liability [Line Items]
Standard product warranty liability	$ 131,740	$ 94,200	$ 79,482	$ 74,217
Motorcycles | All Countries, Excluding Japan
Product Warranty Liability [Line Items]
Standard product warranty, period (in years)	2 years
Motorcycles | Japan
Product Warranty Liability [Line Items]
Standard product warranty, period (in years)	3 years
Parts And Accessories And General Merchandise
Product Warranty Liability [Line Items]
Standard product warranty, period (in years)	1 year
Recall Campaign
Product Warranty Liability [Line Items]
Standard product warranty liability	$ 73,300	$ 35,300	$ 13,600