Restructuring Expenses Restructuring Expenses (Narrative) (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jul. 01, 2018 USD ($) Rate	Jul. 01, 2018 USD ($) Employees Rate
2018 Kansas City Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Number of Positions Eliminated | Employees		800
Restructuring and Related Cost, Expected Number of Positions Added | Employees		450
2018 Adelaide Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Number of Positions Eliminated | Employees		90
Motorcycles and Related Products
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost, Percentage Paid In Cash | Rate	70.00%	70.00%
Motorcycles and Related Products | Temporary Inefficiencies [Member] | Cost of Sales
Restructuring Cost and Reserve [Line Items]
Cost of Goods Sold	$ 2.4	$ 3.1
Minimum [Member] | Motorcycles and Related Products
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	170.0	170.0
Minimum [Member] | Motorcycles and Related Products | Restructuring Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	135.0	135.0
Minimum [Member] | Motorcycles and Related Products | Temporary Inefficiencies [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	35.0	35.0
Minimum [Member] | Motorcycles and Related Products | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	50.0	50.0
Minimum [Member] | Motorcycles and Related Products | Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	45.0	45.0
Minimum [Member] | Motorcycles and Related Products | Project Implementation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	40.0	40.0
Maximum [Member] | Motorcycles and Related Products
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	200.0	200.0
Maximum [Member] | Motorcycles and Related Products | Restructuring Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	155.0	155.0
Maximum [Member] | Motorcycles and Related Products | Temporary Inefficiencies [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	45.0	45.0
Maximum [Member] | Motorcycles and Related Products | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	60.0	60.0
Maximum [Member] | Motorcycles and Related Products | Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	50.0	50.0
Maximum [Member] | Motorcycles and Related Products | Project Implementation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	$ 45.0	$ 45.0