Victory Motorcycles Wind Down (Liability Balance) (Details) - Victory Motorcycles - Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Abandonment $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Disposal Group, Including Discontinued Operation, Liabilities [Roll Forward]
Reserves balance as of January 1, 2018	$ 5,645
Expenses	1,388
Cash payments / scrapped inventory	(3,382)
Reserves balance as of March 31, 2018	3,651
Contract termination charges
Disposal Group, Including Discontinued Operation, Liabilities [Roll Forward]
Reserves balance as of January 1, 2018	3,187
Expenses	764
Cash payments / scrapped inventory	(2,813)
Reserves balance as of March 31, 2018	1,138
Inventory charges
Disposal Group, Including Discontinued Operation, Liabilities [Roll Forward]
Reserves balance as of January 1, 2018	777
Expenses	0
Cash payments / scrapped inventory	(29)
Reserves balance as of March 31, 2018	748
Other costs
Disposal Group, Including Discontinued Operation, Liabilities [Roll Forward]
Reserves balance as of January 1, 2018	1,681
Expenses	624
Cash payments / scrapped inventory	(540)
Reserves balance as of March 31, 2018	$ 1,765