Accounts Receivable Accounts Receivable (Details) $ in Thousands, £ in Millions	Sep. 30, 2015 GBP (£)	Sep. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable		$ 364,364	$ 363,104
Less: Allowance for doubtful accounts		(5,248)	(5,826)
Accounts receivable, net		359,116	357,278
Accounts receivable - trade [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable		317,102	304,087
Accounts receivable - grants from outside parties [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable		25,009	32,076	$ 29,300
Accounts receivable - insurance and other third-party claims [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable		22,253	$ 26,941
Freightliner [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, net	£ 41.6	$ 62,900