CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current Assets:
Cash and cash equivalents	$ 12.1	$ 28.5
Receivables:
Trade, net	115.8	103.5
Affiliates	3.5	1.1
Other	8.5	15.7
Gas transportation receivables	6.0	7.8
Costs recoverable from customers	1.5	0.8
Gas and liquids stored underground	2.1	0.7
Prepayments	10.2	12.9
Other current assets	6.3	6.1
Total current assets	166.0	177.1
Property, Plant and Equipment:
Natural gas transmission and other plant	8,584.0	8,548.8
Construction work in progress	186.4	174.5
Property, plant and equipment, gross	8,770.4	8,723.3
Less—accumulated depreciation and amortization	1,556.0	1,489.2
Property, plant and equipment, net	7,214.4	7,234.1
Other Assets:
Goodwill	215.5	215.5
Gas stored underground	84.5	79.7
Investment in unconsolidated affiliates	1.8	78.6
Other	127.3	129.5
Total other assets	429.1	503.3
Total Assets	7,809.5	7,914.5
Payables:
Trade	44.4	65.1
Affiliates	1.9	1.2
Other	5.3	5.7
Gas Payables:
Transportation	14.9	8.8
Storage	0.1	0.2
Accrued taxes, other	29.3	46.1
Accrued interest	31.2	45.4
Accrued payroll and employee benefits	12.4	26.4
Deferred income	11.7	9.3
Other current liabilities	27.5	27.8
Total current liabilities	178.7	236.0
Long-term debt and capital lease obligations	3,374.8	3,424.4
Other Liabilities and Deferred Credits:
Pension liability	17.1	17.1
Asset retirement obligation	37.9	39.3
Provision for other asset retirement	58.2	57.6
Payable to affiliate	16.0	16.0
Other	63.8	60.7
Total other liabilities and deferred credits	193.0	190.7
Commitments and Contingencies
Equity:
Common units – 243.3 million units issued and outstanding as of March 31, 2014, and December 31, 2013	4,047.1	3,963.4
General partner	79.0	77.3
Accumulated other comprehensive loss	(65.7)	(63.8)
Total partners’ capital	4,060.4	3,976.9
Noncontrolling interest	2.6	86.5
Total Equity	4,063.0	4,063.4
Total Liabilities and Equity	$ 7,809.5	$ 7,914.5