Derivative Financial Instruments Foreign Currency Exchange Rate Risk (Details) £ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2015 GBP (£)	Mar. 31, 2015 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 GBP (£)	Jun. 30, 2017 USD ($)	Mar. 25, 2015 GBP (£)	Mar. 25, 2015 USD ($)
Derivative [Line Items]
Foreign subsidiaries third-party debt denominated in local currencies | $								$ 1,100,000,000
Intercompany loan, amount									£ 120,000	$ 181,000,000
Foreign Exchange Forward [Member]
Derivative [Line Items]
Gain/(loss) reclassified from accumulated other comprehensive income/(loss) into earnings due to ineffectiveness | $	$ 0	$ 0			$ 0	$ 0
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion | $	$ 100,000	$ 300,000			300,000	$ 300,000
Existing net gains expected to be realized within the next 12 months | $					$ 600,000
British Pound Foreign Currency Forward Contract 1 [Member]
Derivative [Line Items]
Effective Date					Mar. 25, 2015
Settlement Date					Mar. 31, 2020
Notional Amount							£ 60,000
Exchange Rate							1.51	1.51
British Pound Foreign Currency Forward Contract 2 [Member]
Derivative [Line Items]
Effective Date					Mar. 25, 2015
Settlement Date					Mar. 31, 2020
Notional Amount							£ 60,000
Exchange Rate							1.50	1.50
British Pound Foreign Currency Forward Contract 3 [Member]
Derivative [Line Items]
Effective Date					Jun. 30, 2015
Settlement Date					Mar. 31, 2020
Notional Amount							£ 2,035
Exchange Rate							1.57	1.57
British Pound Foreign Currency Forward Contract 4 [Member]
Derivative [Line Items]
Effective Date					Sep. 30, 2015
Settlement Date					Mar. 31, 2020
Notional Amount							£ 1,846
Exchange Rate							1.51	1.51
British Pound Foreign Currency Forward Contract 5 [Member]
Derivative [Line Items]
Effective Date					Dec. 31, 2015
Settlement Date					Mar. 31, 2020
Notional Amount							£ 1,873
Exchange Rate							1.48	1.48
British Pound Foreign Currency Forward Contract 6 [Member]
Derivative [Line Items]
Effective Date					Mar. 31, 2016
Settlement Date					Mar. 31, 2020
Notional Amount							£ 1,881
Exchange Rate							1.45	1.45
British Pound Foreign Currency Forward Contract 7 [Member]
Derivative [Line Items]
Effective Date					Jun. 30, 2016
Settlement Date					Mar. 31, 2020
Notional Amount							£ 1,909
Exchange Rate							1.35	1.35
British Pound Foreign Currency Forward Contract 8 [Member]
Derivative [Line Items]
Effective Date					Sep. 30, 2016
Settlement Date					Mar. 31, 2020
Notional Amount							£ 1,959
Exchange Rate							1.33	1.33
British Pound Foreign Currency Forward Contract 9 [Member]
Derivative [Line Items]
Effective Date					Dec. 31, 2016
Settlement Date					Mar. 31, 2020
Notional Amount							£ 1,989
Exchange Rate							1.28	1.28
British Pound Foreign Currency Forward Contract 10 [Member]
Derivative [Line Items]
Effective Date					Mar. 31, 2017
Settlement Date					Mar. 31, 2020
Notional Amount							£ 1,975
Exchange Rate							1.30	1.30
British Pound Foreign Currency Forward Contract 11 [Member]
Derivative [Line Items]
Effective Date					Jun. 30, 2017
Settlement Date					Mar. 31, 2020
Notional Amount							£ 2,026
Exchange Rate							1.34	1.34
Freightliner [Member]
Derivative [Line Items]
Cash consideration			£ 492,100	$ 733,000,000
Intercompany Loan [Member]
Derivative [Line Items]
Accrued Liabilities							£ 17,500	$ 22,400,000