Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2011

Commitments and Contingencies [Abstract]

Summary of Contractual Obligations

 The following table presents our estimated firm purchase commitments (in terms of volumes and costs) under these agreements for the periods indicated (dollars in millions):

	Payment or Settlement due by Period
Contractual Obligations	Total		Remainder  of 2011		2012		2013		2014		2015		Thereafter
Purchase obligations:
Product purchase commitments:
Estimated payment obligations:
Natural gas	$	3,416.7	$	131.9	$	593.6	$	587.3	$	572.2	$	496.8	$	1,034.9
Underlying major volume commitments:
Natural gas (in BBtus) (1)		1,006,775		38,887		175,113		173,375		168,800		146,000		304,600
(1)   Volume is measured in billion British thermal units (“BBtus”).