Derivative Financial Instruments Foreign Currency Exchange Rate Risk (Details)		3 Months Ended					9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended
	Sep. 30, 2013 USD ($)	Dec. 31, 2012 The Swap [Member] USD ($)	Dec. 01, 2010 The Swap [Member] USD ($)	Dec. 01, 2010 The Swap [Member] AUD	Dec. 03, 2012 The New Swap [Member] USD ($)	Dec. 03, 2012 The New Swap [Member] AUD	Sep. 30, 2013 The New Swap [Member] AUD BBSW Interest Rate [Member]	Sep. 30, 2013 The New Swap [Member] LIBOR Interest Rate [Member]	Sep. 30, 2013 The New Swap [Member] Not Designated as Hedging Instrument [Member] USD ($)	Sep. 30, 2013 The New Swap [Member] Not Designated as Hedging Instrument [Member] USD ($)	Dec. 31, 2010 FreightLink [Member] USD ($)	Dec. 31, 2010 FreightLink [Member] AUD
Derivatives [Line Items]
Third party debt related to foreign operations denominated in foreign currencies	$ 155,900,000
Total consideration											320,000,000	331,900,000
Notional amount			100,600,000	105,000,000	109,600,000	105,000,000
Derivative settlement payment		9,100,000
Description of variable rate basis							Australian dollar BBSW plus 3.25%	London Interbank Offered Rate (LIBOR) plus 2.82%
Derivative, Basis Spread On Variable Rate on Cross Currency Derivative							3.25%	2.82%
Realized net interest expense as a result of the quarterly net settlement payments									$ 640,000	$ 2,172,000