CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Current Assets:
Cash and cash equivalents	$ 53.9	$ 55.0
Receivables:
Trade, net	87.2	101.0
Other	15.4	5.2
Gas transportation receivables	10.5	12.2
Costs recoverable from customers	11.2	11.3
Gas stored underground	10.0	3.6
Prepayments	16.0	11.4
Other current assets	3.4	3.5
Total current assets	207.6	203.2
Property, Plant and Equipment:
Natural gas transmission and other plant	6,974.1	6,933.9
Construction work in progress	111.2	109.9
Property, plant and equipment, gross	7,085.3	7,043.8
Less-accumulated depreciation and amortization	888.4	785.8
Property, plant and equipment, net	6,196.9	6,258.0
Other Assets:
Goodwill	163.5	163.5
Gas stored underground	124.9	125.8
Costs recoverable from customers	15.5	15.7
Other	85.8	111.8
Total other assets	389.7	416.8
Total Assets	6,794.2	6,878.0
Payables:
Trade	29.9	48.8
Affiliate	2.5	3.2
Other	13.8	10.1
Gas Payables:
Transportation	14.5	20.5
Storage	5.6	4.2
Accrued taxes, other	44.4	40.4
Accrued interest	47.4	40.5
Accrued payroll and employee benefits	14.0	17.0
Construction retainage	3.4	8.3
Deferred income	2.7	6.3
Other current liabilities	12.3	14.5
Total current liabilities	190.5	213.8
Long-term debt	3,022.3	3,152.3
Long-term debt - affiliate	100.0	100.0
Total long-term debt	3,122.3	3,252.3
Other Liabilities and Deferred Credits:
Pension liability	25.5	27.0
Asset retirement obligation	16.5	17.2
Provision for other asset retirement	52.4	51.7
Payable to affiliate	16.0	16.0
Other	63.7	58.6
Total other liabilities and deferred credits	174.1	170.5
Partners' Capital:
Common units - 175.7 million and 169.7 million units issued and outstanding as of June 30, 2011, and December 31, 2010	2,604.1	2,534.4
Class B units - 22.9 million units issued and outstanding as of June 30, 2011, and December 31, 2010	679.3	683.6
General partner	64.1	62.9
Accumulated other comprehensive loss	(40.2)	(39.5)
Total partners' capital	3,307.3	3,241.4
Total Liabilities and Partners' Capital	$ 6,794.2	$ 6,878.0