Investments in Affiliated Companies (Future Debt Maturities) (Details 8) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
2016		$ 564.8
2017		412.7
2018		517.9
2019		550.0
2020		350.0
Thereafter		1,810.0
Total debt principal		4,205.4	$ 4,203.8
RRPF Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Total debt principal	[1]	$ 2,387.1

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