Restructuring Expenses - Restructuring Plan Reserve Recorded in Accrued Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Restructuring expense	$ 32,353	$ 93,401	$ 0
Motorcycles
Restructuring Reserve [Roll Forward]
Balance, beginning of period	28,498	0
Restructuring expense	32,353	93,401	0
Utilized - cash	(44,170)	(29,599)
Utilized - non cash	(15,778)	(34,654)
Foreign currency changes	(36)	(650)
Balance, end of period	867	28,498	0
Motorcycles | 2018 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance, beginning of period	25,037	0
Restructuring expense	32,670	89,502
Utilized - cash	(41,052)	(29,155)
Utilized - non cash	(15,778)	(34,654)
Foreign currency changes	(10)	(656)
Balance, end of period	867	25,037	0
Motorcycles | 2018 Reorganization Plan
Restructuring Reserve [Roll Forward]
Balance, beginning of period	3,461	0
Restructuring expense	(317)	3,899
Utilized - cash	(3,118)	(444)
Utilized - non cash	0	0
Foreign currency changes	(26)	6
Balance, end of period	0	3,461	0
Motorcycles | Employee Severance | 2018 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance, beginning of period	24,958	0
Restructuring expense	15	38,666
Utilized - cash	(24,102)	(13,060)
Utilized - non cash	0	0
Foreign currency changes	(6)	(648)
Balance, end of period	865	24,958	0
Motorcycles | Accelerated Depreciation | 2018 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0	0
Restructuring expense	14,684	34,654
Utilized - cash	0	0
Utilized - non cash	(14,684)	(34,654)
Foreign currency changes	0	0
Balance, end of period	0	0	0
Motorcycles | Other Project Implementation Costs | 2018 Restructuring Plan
Restructuring Reserve [Roll Forward]
Balance, beginning of period	79	0
Restructuring expense	17,971	16,182
Utilized - cash	(16,950)	(16,095)
Utilized - non cash	(1,094)	0
Foreign currency changes	(4)	(8)
Balance, end of period	$ 2	$ 79	$ 0