Changes in Operations Freightliner Fair Value Assigned to Acquired Net Assets (Details) £ in Thousands, € in Millions	Dec. 31, 2015 GBP (£)	Dec. 31, 2015 USD ($)	Mar. 31, 2015 GBP (£)	Mar. 31, 2015 USD ($)	Mar. 25, 2015 GBP (£)	Mar. 25, 2015 EUR (€)	Mar. 25, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Goodwill		$ 826,575,000						$ 628,815,000	$ 630,462,000
Freightliner [Member]
Cash and cash equivalents	£ 30,030	44,733,000
Accounts receivable	55,530	82,717,000
Materials and supplies	9,740	14,509,000
Prepaid expenses and other	19,156	28,535,000
Property and equipment	198,730	296,028,000
Goodwill	145,190	216,275,000
Intangible assets	392,233	584,270,000
Other assets	179	267,000
Total assets	850,788	1,267,334,000
Current portion of long-term debt	17,119	25,500,000
Accounts payable and accrued expenses	105,531	157,201,000
Long-term debt, less current portion	67,057	99,888,000
Deferred income tax liabilities, net	82,137	122,351,000
Other long-term liabilities	62,661	93,340,000
Net assets	£ 516,283	$ 769,054,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount							$ 0
Business Combination, Assumed, Bank Guarantees			£ 2,500	$ 3,600,000		€ 3.4	3,700,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Pension Liability					£ 57,200		85,200,000
Capital Lease Obligations [Member] | Freightliner [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Capital Lease Obligation					67,057		99,888,000
Capital Lease Obligations [Member] | Freightliner [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Capital Lease Obligation					16,500		24,500,000
Other long-term liabilities [Member] | Freightliner [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Pension Liability					51,000		76,000,000
Accounts Payable and Accrued Liabilities [Member] | Freightliner [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Pension Liability					£ 6,200		$ 9,200,000