CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Operating Activities:
Net Income	$ 216.7	$ 145.4
Adjustments to reconcile net income to cash provided by operations:
Depreciation and amortization	184.8	168.9
Amortization of deferred costs	4.4	8.1
Asset impairment	8.2	28.6
Loss on early retirement of debt	0	13.2
Storage gas loss	0	3.7
Equity losses in unconsolidated affiliate	0.4	0
Net gain on disposal of operating assets	2.6	3.9
Changes in operating assets and liabilities:
Trade and other receivables	(25.5)	(13.8)
Other receivables, affiliates	0.5	0.8
Gas receivables and storage assets	7.2	3.8
Costs recoverable from customers	(5.6)	2.7
Other assets	15.6	13.1
Trade and other payables	(9.7)	(10.2)
Other payables, affiliates	(1.1)	(0.2)
Gas payables	3.7	(0.8)
Accrued liabilities	7.7	9.8
Other liabilities	(6.2)	(10.5)
Net cash provided by operating activities	414.1	345.5
Investing Activities:
Capital expenditures	135.5	116.9
Proceeds from sale of operating assets	5.6	17.5
Proceeds from insurance and other recoveries	10.4	0
Net cash used in investing activities	(119.5)	(99.4)
Financing Activities:
Proceeds from long-term debt, net of issuance costs	296.5	437.6
Repayment of borrowings from long-term debt	225.0	250.0
Payments of premiums on extinguishment of long-term debt	0	21.0
Proceeds from borrowings on revolving credit agreement	1,480.0	515.0
Repayment of borrowings on revolving credit agreement	1,588.5	760.0
Payments of financing fees related to revolving credit facility	(3.8)	0
Repayment of borrowings from term loan	200.0	0
Advances from affiliate	(2.5)	0
Repayment of contribution received related to predecessor equity	284.8	0
Distributions paid	350.6	312.1
Proceeds from sale of common units	556.3	170.0
Capital contribution from general partner	11.8	3.6
Net cash used in financing activities	(305.6)	(216.9)
Decrease in cash and cash equivalents	(11.0)	29.2
Cash and cash equivalents at beginning of period	21.9	55.0
Cash and cash equivalents at end of period	$ 10.9	$ 84.2