Restructuring (Restructuring Plan Reserve Recorded in Accrued Liabilities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Reserve [Roll Forward]
Restructuring expense	$ 93,401	$ 0	$ 0
Motorcycles
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0
Restructuring expense	93,401	0	$ 0
Utilized - cash	(29,599)
Utilized - non cash	(34,654)
Foreign currency changes	(650)
Balance, end of period	28,498	0
Motorcycles | 2018 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0
Restructuring expense	89,502
Utilized - cash	(29,155)
Utilized - non cash	(34,654)
Foreign currency changes	(656)
Balance, end of period	25,037	0
Motorcycles | 2018 Reorganization Plan
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0
Restructuring expense	3,899
Utilized - cash	(444)
Utilized - non cash	0
Foreign currency changes	6
Balance, end of period	3,461	0
Motorcycles | Employee Severance | 2018 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0
Restructuring expense	38,666
Utilized - cash	(13,060)
Utilized - non cash	0
Foreign currency changes	(648)
Balance, end of period	24,958	0
Motorcycles | Accelerated Depreciation | 2018 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0
Restructuring expense	34,654
Utilized - cash	0
Utilized - non cash	(34,654)
Foreign currency changes	0
Balance, end of period	0	0
Motorcycles | Other Project Implementation Costs | 2018 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0
Restructuring expense	16,182
Utilized - cash	(16,095)
Utilized - non cash	0
Foreign currency changes	(8)
Balance, end of period	$ 79	$ 0