CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 111.4	$ 3.1
Receivables:
Trade, net	105.3	117.2
Other	14.2	12.3
Gas transportation receivables	(7.0)	(5.6)
Gas and liquids stored underground	12.4	10.7
Prepayments	20.1	16.9
Other current assets	1.9	4.0
Total current assets	272.3	169.8
Property, Plant and Equipment:
Natural gas transmission and other plant	9,871.7	9,504.7
Construction work in progress	284.5	201.9
Property, plant and equipment, gross	10,156.2	9,706.6
Less—accumulated depreciation and amortization	2,258.0	2,052.2
Property, plant and equipment, net	7,898.2	7,654.4
Other Assets:
Goodwill	237.4	237.4
Gas stored underground	94.6	97.6
Other	140.2	141.1
Total other assets	472.2	476.1
Total Assets	8,642.7	8,300.3
Payables:
Trade	95.6	99.1
Affiliates	1.4	1.3
Other	22.6	19.5
Gas payables	5.4	4.7
Accrued taxes, other	73.2	47.3
Accrued interest	45.5	39.7
Accrued payroll and employee benefits	32.9	33.2
Construction retainage	18.9	10.7
Deferred income	8.0	6.9
Other current liabilities	27.8	52.0
Total current liabilities	331.3	314.4
Long-term debt and capital lease obligation	3,626.8	3,459.3
Other Liabilities and Deferred Credits:
Pension liability	21.7	24.3
Asset retirement obligation	44.6	38.1
Provision for other asset retirement	62.2	57.2
Payable to affiliate	16.0	16.0
Other	72.0	64.3
Total other liabilities and deferred credits	216.5	199.9
Commitments and Contingencies
Partners’ Capital:
Common units - 250.3 million units issued and outstanding as of September 30, 2016, and December 31, 2015	4,460.7	4,326.2
General partner	87.6	84.8
Accumulated other comprehensive loss	(80.2)	(84.3)
Total partners’ capital	4,468.1	4,326.7
Total Liabilities and Partners' Capital	$ 8,642.7	$ 8,300.3