Presentation (Details) $ in Billions	Dec. 31, 2017 USD ($)
Forso Nordic AB [Member]
Presentation [Line Items]
Equity Method Investment, Ownership Percentage	50.00%
Forso Nordic AB [Member]
Presentation [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	$ 1.7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	$ 1.6