Disclosures About Derivative Instruments and Hedging Activities (Details 1) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Balance sheet location and fair value of derivative assets and liabilities
Derivative Liability, Fair Value, Net	$ 43.2	$ 121.1
Derivative Asset, Fair Value, Net	53.8	11.4
Designated as Hedging Instrument [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Liability, Fair Value, Net	38.5	103.5
Derivative Asset, Fair Value, Net	41.3	7.7
Derivative Financial Instruments and Other Assets [Member] | Designated as Hedging Instrument [Member] | Commodity Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Asset, Fair Value, Net	40.9	3.5
Derivative Financial Instruments and Other Assets [Member] | Designated as Hedging Instrument [Member] | Foreign Currency Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Asset, Fair Value, Net	0.4
Other Noncurrent Liabilities [Member] | Designated as Hedging Instrument [Member] | Foreign Currency Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Liability, Fair Value, Net	7.2
Derivative Financial Instruments and Other Noncurrent Liabilities [Member] | Designated as Hedging Instrument [Member] | Commodity Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Liability, Fair Value, Net		29.3
Derivative Financial Instruments and Other Noncurrent Liabilities [Member] | Designated as Hedging Instrument [Member] | Foreign Currency Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Liability, Fair Value, Net		2.4
Derivative Financial Instruments and Other Noncurrent Liabilities [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Liability, Fair Value, Net	29.2	71.8
Derivative Financial Instruments and Other Noncurrent Liabilities [Member] | Derivatives Subject to Utility Rate Regulation [Member] | Commodity Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Liability, Fair Value, Net	3.3	9.0
Derivative Financial Instruments [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Asset, Fair Value, Net		4.2
Derivative Financial Instruments [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Commodity Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Asset, Fair Value, Net	10.6	3.3
Derivative Financial Instruments [Member] | Derivatives Subject to Utility Rate Regulation [Member] | Commodity Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Asset, Fair Value, Net	1.9	0.4
Derivative Financial Instruments, Liabilities [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Commodity Contracts [Member]
Balance sheet location and fair value of derivative assets and liabilities
Derivative Liability, Fair Value, Net	$ 1.4	$ 8.6