Victory Motorcycles Wind Down - Wind Down Charges (Details) - Victory Motorcycles - Disposal Group, Disposed of by Means Other than Sale, Not Discontinued Operations, Abandonment $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Charges related to the wind down plan	$ 59,792
Contract termination charges
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Charges related to the wind down plan	21,632
Asset impairment charges
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Charges related to the wind down plan	18,760
Inventory charges
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Charges related to the wind down plan	10,169
Other costs
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Charges related to the wind down plan	$ 9,231