Investments in Affiliated Companies (Future Debt Maturities) (Details 9) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 433.8
Long-term Debt, Maturities, Repayments of Principal in Year Two	566.7
Long-term Debt, Maturities, Repayments of Principal in Year Three	660.7
Long-term Debt, Maturities, Repayments of Principal in Year Four	427.0
Long-term Debt, Maturities, Repayments of Principal in Year Five	514.0
Long-term Debt, Maturities, Repayments of Principal after Year Five	1,239.8
Total Debt	3,838.5		3,283.0
RRPF Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	67.1
Long-term Debt, Maturities, Repayments of Principal in Year Two	272.0
Long-term Debt, Maturities, Repayments of Principal in Year Three	450.4
Long-term Debt, Maturities, Repayments of Principal in Year Four	245.6
Long-term Debt, Maturities, Repayments of Principal in Year Five	100.3
Long-term Debt, Maturities, Repayments of Principal after Year Five	888.0
Total Debt	$ 2,023.4	[1]

[1] (1) All debt obligations are nonrecourse to the shareholders