Derivative Financial Instruments and Hedging Activities Interest Rate Swaps and Fuel Hedge Contracts Narrative (Details) (Interest rate swaps [Member], Not Designated as Hedging Instrument [Member])	Dec. 31, 2013
Derivative [Line Items]
Percentage of JV variable debt hedged by interest rate derivatives	95.00%	[1]
Senior Secured Facilities Agreement, Revolving Cash Advance Facility [Member]
Derivative [Line Items]
Percentage of JV variable debt hedged by interest rate derivatives	95.00%

[1] All notional amounts are stated in thousands of dollars except fuel hedge contracts which are denominated in thousands of barrels.