Investments in Affiliated Companies (Balance Sheet, Affiliates) (Details 5) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Summarized balance sheet for all affiliated companies
Current assets	$ 254.1	$ 185.0
Noncurrent assets	3,363.6	3,254.1
Total assets	3,617.7	3,439.1
Current liabilities	551.0	285.5
Noncurrent liabilities	2,341.4	2,512.2
Shareholders’ equity	725.3	641.4
Total liabilities and shareholders' equity	$ 3,617.7	$ 3,439.1