Acquisition Purchase Price Allocation (Details) - USD ($) $ in Millions	1 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Jun. 29, 2015
Assets acquired
Current assets			$ 1,178.2
Property, plant and equipment			7,098.2
Goodwill	$ 2,944.6	$ 2,944.6
Other long-term assets, excluding Goodwill			2,410.5
Liabilities assumed
Current liabilities, including current maturities of long-term debt			(1,260.1)
Deferred credits and other liabilities			(3,769.6)
Long-term debt			(2,967.6)
Preferred stock of subsidiary			$ (51.1)
Acquisition purchase price	$ 5,583.1