CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 77.3	$ 4.6
Receivables:
Trade, net	101.6	127.1
Other	11.2	12.7
Gas transportation receivables	4.3	8.2
Gas and liquids stored underground	4.7	1.3
Prepayments	21.9	17.7
Other current assets	1.1	2.6
Total current assets	222.1	174.2
Property, Plant and Equipment:
Natural gas transmission and other plant	10,035.0	9,958.8
Construction work in progress	463.6	368.5
Property, plant and equipment, gross	10,498.6	10,327.3
Less—accumulated depreciation and amortization	2,468.1	2,333.8
Property, plant and equipment, net	8,030.5	7,993.5
Other Assets:
Goodwill	237.4	237.4
Gas stored underground	95.7	93.5
Other	137.6	139.2
Total other assets	470.7	470.1
Total Assets	8,723.3	8,637.8
Payables:
Trade	103.3	113.8
Affiliates	1.5	1.4
Other	25.0	23.7
Gas payables	7.8	6.7
Accrued taxes, other	53.1	52.7
Accrued interest	43.9	40.6
Accrued payroll and employee benefits	26.5	38.5
Construction retainage	17.8	19.6
Deferred income	5.5	7.5
Other current liabilities	25.0	28.4
Total current liabilities	309.4	332.9
Long-term debt and capital lease obligation	3,574.5	3,558.0
Other Liabilities and Deferred Credits:
Pension liability	22.2	22.0
Asset retirement obligation	44.3	44.7
Provision for other asset retirement	65.4	63.7
Payable to affiliate	16.0	16.0
Other	68.2	69.6
Total other liabilities and deferred credits	216.1	216.0
Commitments and Contingencies
Partners’ Capital:
Common units - 250.3 million units issued and outstanding as of June 30, 2017, and December 31, 2016	4,612.2	4,522.2
General partner	90.7	88.8
Accumulated other comprehensive loss	(79.6)	(80.1)
Total partners’ capital	4,623.3	4,530.9
Total Liabilities and Partners' Capital	$ 8,723.3	$ 8,637.8