Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Current assets and current liabilities [Abstract]
Threshold for components of total current assets and liabilities to be presented as an individual caption on Consolidated Balance Sheet (in hundredths)	5.00%
Deferred revenues [Abstract]
Deferred revenues	$ 82.1		$ 109.1
Environmental costs [Abstract]
Environmental reserves - current portion	6.5		4.5
Other Nonoperating Income (Expense) [Abstract]
Gain on sales of available-for-sale equity securities of Energy Transfer Equity	68.8	[1]	0	[1]	0	[1]
Distribution income from Energy Transfer Equity	4.1		0		0
Other	(0.3)		(0.6)		2.7
Total	72.6		(0.6)		2.7
Restricted cash [Abstract]
Restricted cash	4.3		38.5
Allowance for Doubtful Accounts, Current [Member]
Movement in valuation allowances and reserves [Roll Forward]
Balance at beginning of period	13.4		18.4		16.8
Charged to costs and expenses	0.3		0.8		2.6
Acquisition-related additions and other	0		0		1.1
Deductions	(0.5)	[2]	(5.8)	[2]	(2.1)	[2]
Balance at end of period	13.2		13.4		18.4
Reserve for Environmental Costs [Member]
Movement in valuation allowances and reserves [Roll Forward]
Balance at beginning of period	12.3		12.4		16.7
Charged to costs and expenses	13.9		9.3		2.8
Acquisition-related additions and other	5.2		1.0		0.9
Deductions	(17.7)		(10.4)		(8.0)
Balance at end of period	$ 13.7		$ 12.3		$ 12.4

[1] See Note 9 for information regarding the liquidation of our investment in limited partnership units of Energy Transfer Equity.

[2] The 2011 deduction amount is primarily due to our reassessment of the allowance for doubtful accounts as a result of improved credit ratings of a customer, which reduced our exposure to potential uncollectibility.