Changes in Operations Freightliner Fair Values Assigned to Acquired Net Assets (Details) £ in Thousands, € in Millions	6 Months Ended
	Jun. 30, 2015 USD ($)	Mar. 25, 2015 EUR (€)	Mar. 25, 2015 GBP (£)	Mar. 25, 2015 USD ($)	Dec. 31, 2014 USD ($)
Goodwill	$ 964,882,000				$ 628,815,000
Freightliner [Member]
Cash and cash equivalents			£ 31,840	$ 47,429,000
Accounts receivable			54,416	81,058,000
Materials and supplies			9,740	14,509,000
Prepaid expenses and other			17,292	25,758,000
Property and equipment			160,500	239,081,000
Goodwill			218,433	325,378,000
Intangible assets			360,100	536,405,000
Other assets			351	523,000
Total assets			852,672	1,270,141,000
Current portion of long-term debt			13,946	20,774,000
Accounts payable and accrued expenses			101,297	150,893,000
Deferred income tax liabilities, net			122,167	181,980,000
Other long-term liabilities			59,484	88,607,000
Net assets			516,040	768,693,000
Weighted average amortization period of amortizable intangible assets acquired	85 years
Expected tax deductible amount of goodwill				0
Capital lease liability assumed			12,500	18,600,000
Assumed bank guarantees		€ 3.4		3,700,000
Pension liability assumed			57,200	85,200,000
Other long-term liabilities [Member] | Freightliner [Member]
Pension liability assumed			51,000	76,000,000
Accounts payable and accrued liabilities [Member] | Freightliner [Member]
Pension liability assumed			6,200	9,200,000
Capital Lease Obligations [Member] | Freightliner [Member]
Long-term debt, less current portion			£ 39,738	$ 59,194,000