Basis of Presentation Revision of Financial Statements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revision of Financial Statements [Line Items]
Operating Expenses	$ 1,641.0	$ 566.2
As reported [Member]
Revision of Financial Statements [Line Items]
Revenue from Purchased Oil and Gas		167.3
Revenues		491.6
Cost of Purchased Oil and Gas		169.4
Operating Expenses		589.7
As revised [Member]
Revision of Financial Statements [Line Items]
Revenue from Purchased Oil and Gas		143.8
Revenues		468.1
Cost of Purchased Oil and Gas		145.9
Operating Expenses		566.2
Change [Member]
Revision of Financial Statements [Line Items]
Revenue from Purchased Oil and Gas		(23.5)
Revenues		(23.5)
Cost of Purchased Oil and Gas		(23.5)
Operating Expenses		$ (23.5)