Victory Motorcycles Wind Down - Liability Balance (Details) - Victory Motorcycles - Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Abandonment - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reserves balance as of January 1, 2017	$ 5,645	$ 0
Expenses	5,063	41,032
Cash payments / scrapped inventory	(8,011)	(35,387)
Reserves balance as of December 31, 2017	2,697	5,645
Contract termination charges
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reserves balance as of January 1, 2017	3,187	0
Expenses	3,433	21,632
Cash payments / scrapped inventory	5,155	18,445
Reserves balance as of December 31, 2017	1,465	3,187
Inventory charges
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reserves balance as of January 1, 2017	777	0
Expenses	0	10,169
Cash payments / scrapped inventory	399	9,392
Reserves balance as of December 31, 2017	378	777
Other costs
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reserves balance as of January 1, 2017	1,681	0
Expenses	1,630	9,231
Cash payments / scrapped inventory	2,457	7,550
Reserves balance as of December 31, 2017	$ 854	$ 1,681