CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 9.3	$ 3.1
Receivables:
Trade, net	112.8	117.2
Other	10.5	12.3
Gas transportation receivables	2.1	5.6
Gas and liquids stored underground	11.6	10.7
Prepayments	13.1	16.9
Other current assets	5.5	4.0
Total current assets	164.9	169.8
Property, Plant and Equipment:
Natural gas transmission and other plant	9,544.9	9,504.7
Construction work in progress	260.9	201.9
Property, plant and equipment, gross	9,805.8	9,706.6
Less—accumulated depreciation and amortization	2,127.3	2,052.2
Property, plant and equipment, net	7,678.5	7,654.4
Other Assets:
Goodwill	237.4	237.4
Gas stored underground	100.0	97.6
Other	139.5	141.1
Total other assets	476.9	476.1
Total Assets	8,320.3	8,300.3
Payables:
Trade	59.6	99.1
Affiliates	1.8	1.3
Other	21.0	19.5
Gas payables	3.8	4.7
Accrued taxes, other	31.2	47.3
Accrued interest	33.6	39.7
Accrued payroll and employee benefits	20.1	33.2
Deferred income	10.3	6.9
Asset retirement obligation	15.8	14.5
Customer rate refunds	16.6	16.3
Other current liabilities	30.0	31.9
Total current liabilities	243.8	314.4
Long-term debt and capital lease obligation	3,475.3	3,459.3
Other Liabilities and Deferred Credits:
Pension liability	24.4	24.3
Asset retirement obligation	38.3	38.1
Provision for other asset retirement	57.4	57.2
Payable to affiliate	16.0	16.0
Other	61.7	64.3
Total other liabilities and deferred credits	$ 197.8	$ 199.9
Commitments and Contingencies
Partners’ Capital:
Common units - 250.3 million units issued and outstanding as of March 31, 2016 and December 31, 2015	$ 4,400.2	$ 4,326.2
General partner	86.3	84.8
Accumulated other comprehensive loss	(83.1)	(84.3)
Total partners’ capital	4,403.4	4,326.7
Total Liabilities and Partners' Capital	$ 8,320.3	$ 8,300.3