Restructuring Expenses Restructuring Expenses (Restructuring Plan Reserve Recorded in Accrued Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 24, 2017	Sep. 30, 2018	Sep. 24, 2017
Restructuring Cost and Reserve
Restructuring reserve, reversal of previously recognized expense	$ 900
Restructuring Reserve [Roll Forward]
Restructuring expense	14,832	$ 0	$ 74,044	$ 0
Motorcycles and Related Products
Restructuring Reserve [Roll Forward]
Balance, beginning of period	36,835		0
Restructuring expense	14,832		74,044
Utilized - cash	(11,455)		(18,055)
Utilized - non cash	(9,420)		(24,779)
Foreign currency changes	(142)		(560)
Balance, end of period	30,650		30,650
Motorcycles and Related Products | Employee Severance
Restructuring Reserve [Roll Forward]
Balance, beginning of period	36,758		0
Restructuring expense	(649)		38,956
Utilized - cash	(5,402)		(7,835)
Utilized - non cash	0		0
Foreign currency changes	(140)		(554)
Balance, end of period	30,567		30,567
Motorcycles and Related Products | Project Implementation Costs
Restructuring Reserve [Roll Forward]
Balance, beginning of period	77		0
Restructuring expense	6,061		10,309
Utilized - cash	(6,053)		(10,220)
Utilized - non cash	0		0
Foreign currency changes	(2)		(6)
Balance, end of period	83		83
Motorcycles and Related Products | Accelerated Depreciation
Restructuring Reserve [Roll Forward]
Balance, beginning of period	0		0
Restructuring expense	9,420		24,779
Utilized - cash	0		0
Utilized - non cash	(9,420)		(24,779)
Foreign currency changes	0		0
Balance, end of period	$ 0		$ 0