CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities
Net income	$ 33.8	$ 69.2
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization in interest expense	4.1	4.8
Compensation on equity grants	3.8	4.5
Depreciation and amortization expense	64.0	47.4
Accretion of asset retirement obligations	1.1	1.0
Deferred income tax expense	0.2	1.4
Equity earnings, net of distributions	(1.6)	0
Risk management activities	(0.2)	0.9
Gain on sale or disposition of assets	(0.1)	0
Changes in operating assets and liabilities:
Receivables and other assets	95.1	119.6
Inventory	33.7	44.3
Accounts payable and other liabilities	(59.9)	(154.3)
Net cash provided by operating activities	174.0	138.8
Cash flows from investing activities
Outlays for property, plant and equipment	(202.9)	(103.0)
Investment in unconsolidated affiliate	0	(6.2)
Return of capital from unconsolidated affiliate	0	0.3
Other, net	(4.6)	0.8
Net cash used in investing activities	(207.5)	(108.1)
Partnership loan facilities:
Proceeds	325.0	545.0
Repayments	(380)	(643)
Partnership accounts receivable securitization facility:
Proceeds	171.4	0
Repayments	(60)	0
Non-Partnership loan facilities:
Proceeds	5.0	0
Repayments	(15.0)	0
Costs incurred in connection with financing arrangements	(1.1)	(4.4)
Distributions to owners	(61.7)	(54.3)
Proceeds from sale of common units of the Partnership	105.3	115.2
Dividends to common and common equivalent shareholders	(19.0)	(13.8)
Net cash provided by (used in) financing activities	69.9	(55.3)
Net change in cash and cash equivalents	36.4	(24.6)
Cash and cash equivalents, beginning of period	76.3	145.8
Cash and cash equivalents, end of period	$ 112.7	$ 121.2