Transactions With Affiliates (Schedule of Long-term Debt) (Details) - Notes Due 2020 - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2016
Dec. 31, 2015
Schedule of Related Party Transactions, Long-Term Debt [Line Items]    
Debt Instrument, Issuance Date Dec. 09, 2013  
Debt Instrument, Interest Rate, Stated Percentage 4.70%  
Debt Instrument, Maturity Date Dec. 31, 2020  
Long-term Debt $ 630.9 $ 630.9