Equity-based Awards (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Equity-based compensation expense [Abstract]
Total compensation expense	$ 60.0		$ 50.9		$ 70.4
Restricted Common Unit Awards [Member]
Equity-based compensation expense [Abstract]
Total compensation expense	57.0		47.5		31.5
Unit Option Awards [Member]
Equity-based compensation expense [Abstract]
Total compensation expense	1.3		3.1		3.4
Other Equity-based Awards [Member]
Equity-based compensation expense [Abstract]
Total compensation expense	1.7	[1]	0.3	[1]	35.5	[1]
Unit Appreciation Rights [Member]
Equity-based compensation expense [Abstract]
Total compensation expense	0.9		(0.4)		3.1
Employee Partnerships [Member]
Equity-based compensation expense [Abstract]
Total compensation expense					$ 31.3
Long-Term Incentive Plan (1998) [Member]
Equity-based compensation expense [Abstract]
Maximum number of common units that may be issued as awards (in units)	7,000,000
Remaining number of common units available to be issued as awards (in units)	852,974
Long-Term Incentive Plan (2008) [Member]
Equity-based compensation expense [Abstract]
Maximum number of common units that may be issued as awards (in units)	10,000,000
Remaining number of common units available to be issued as awards (in units)	5,167,075

[1] Primarily consists of unit appreciation rights ("UARs"), phantom units and similar awards. Also, the amounts presented for 2010 include $31.3 million of compensation expense for awards related to limited partnership interests in the Employee Partnerships, which were liquidated in August 2010.