Derivative Financial Instruments Foreign Currency Exchange Rate Risk (Details) £ in Thousands, $ in Thousands, AUD in Millions			3 Months Ended		12 Months Ended
	Feb. 25, 2015 GBP (£)	Feb. 25, 2015 USD ($)	Mar. 31, 2015 GBP (£)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2016 GBP (£)	Dec. 31, 2016 USD ($)	Mar. 23, 2015 GBP (£)	Feb. 25, 2015 AUD	Feb. 25, 2015 GBP (£)	Feb. 25, 2015 USD ($)
Derivatives [Line Items]
Third party debt related to foreign operations denominated in foreign currencies									$ 945,700
Cash received on settlement of forward currency forward purchase contracts | £										£ 391,800
Loss on settlement of foreign currency forward purchase contracts					$ 0	$ (18,686)	$ 0
Intercompany Loan, Amount								£ 120,000	181,000
Foreign currency forward purchase contract 1 [Member]
Derivatives [Line Items]
Notional Amount												£ 307,100	$ 475,000
Foreign currency forward purchase contract 2 [Member]
Derivatives [Line Items]
Notional Amount											AUD 163.8	£ 84,700
Forward Contracts [Member]
Derivatives [Line Items]
Loss on settlement of foreign currency forward purchase contracts						18,700
Freightliner [Member]
Derivatives [Line Items]
Loss on settlement of foreign currency forward purchase contracts						(18,700)
Cash consideration			£ 492,083	$ 733,006
Scenario, Plan [Member] | Freightliner [Member]
Derivatives [Line Items]
Estimated Payments to Acquire Businesses, Gross	£ 490,000	$ 755,000
Not Designated as Hedging Instrument [Member]
Derivatives [Line Items]
Loss on settlement of foreign currency forward purchase contracts					$ (3,267)	$ (18,686)	$ (1,270)
Accrued interest [Member]
Derivatives [Line Items]
Accumulated accrued interest								£ 13,500	$ 16,600