Equity-Based Compensation Plans And Employee Benefit Plans (Narrative) (Details) (USD $)	12 Months Ended					3 Months Ended	12 Months Ended						3 Months Ended	12 Months Ended						3 Months Ended	12 Months Ended		12 Months Ended								12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Service-Based Awards [Member]	Dec. 31, 2012 Performance-Based Awards [Member]	Mar. 31, 2010 Class B Membership Interests [Member]	Dec. 31, 2010 Class B Membership Interests [Member]	Dec. 31, 2009 Class B Membership Interests [Member]	Dec. 31, 2010 Series B [Member]	Dec. 31, 2012 2010 Long Term Incentive Plan [Member]	Dec. 31, 2011 2010 Long Term Incentive Plan [Member]	Dec. 31, 2010 2010 Long Term Incentive Plan [Member]	Mar. 31, 2010 2007 Long Term Incentive Plan [Member]	Dec. 31, 2012 2007 Long Term Incentive Plan [Member]	Dec. 31, 2011 2007 Long Term Incentive Plan [Member]	Dec. 31, 2010 2007 Long Term Incentive Plan [Member]	Dec. 31, 2012 Stock Appreciation Rights (SARs) [Member]	Dec. 31, 2011 Stock Appreciation Rights (SARs) [Member]	Dec. 31, 2010 Stock Appreciation Rights (SARs) [Member]	Dec. 31, 2011 Bonus Program [Member]	Dec. 31, 2010 Bonus Program [Member]	Dec. 31, 2012 Bonus Program [Member]	Dec. 31, 2012 Profit-Sharing And Retirement Savings Plan [Member]	Dec. 31, 2011 Profit-Sharing And Retirement Savings Plan [Member]	Dec. 31, 2010 Profit-Sharing And Retirement Savings Plan [Member]	Dec. 31, 2012 Health Care Benefit Programs [Member]	Dec. 31, 2011 Health Care Benefit Programs [Member]	Dec. 31, 2010 Health Care Benefit Programs [Member]	Dec. 31, 2011 Class A Units [Member]	Dec. 31, 2011 Waiver Units [Member]	Dec. 31, 2012 Maximum [Member]	Dec. 31, 2011 Maximum [Member]	Dec. 31, 2010 Maximum [Member]	Dec. 31, 2012 Maximum [Member] 2010 Long Term Incentive Plan [Member]	Dec. 31, 2011 Minimum [Member]	Dec. 31, 2010 Minimum [Member]	Dec. 31, 2012 Minimum [Member] 2010 Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of rights (in years), Minimum																															1 year	3 years 4 months 28 days	4 years 4 months 28 days		0 years	0 years
Phantom units awarded during the period				48,785	128,210					176,995	151,916	62,927
Performance Based Award Percentage																																		150.00%			50.00%
Weighted average grant date fair value of phantom unit				$ 30.52	$ 31.38					$ 31.14	$ 27.82	$ 20.64
Forfeited, Number of Phantom Units				1,787	2,679
Unrecognized compensation cost										$ 7,500,000							$ 100,000
Weighted average period of recognition, years										2 years								1 year
Allocated Share-based Compensation Expense	11,179,000	2,555,000	6,117,000							6,700,000	1,900,000		500,000	4,500,000	600,000	5,200,000
Liability for compensation awards										7,200,000	2,000,000
Phantom units vested																123,857
Awards outstanding	384,806,000	662,484,000												0	0
Number of common units per right			1
Term of awards, years																		10 years
Total intrinsic value of rights exercised																	3,300,000	2,400,000	1,300,000
Units received from general partner									767
Number of common units issued	81,202,752	71,965,062																											2,364,279	827,484
Non-cash compensation expense	7,197,000	(15,000)	4,706,000						79,100,000
Deferred compensation expenses							14,900,000	15,400,000
Decrease in compensation expenses						2,100,000
Weighted percentage of target level of available cash before reserves																					90.00%
Weighted percentage of achievement level of available cash before reserves																					10.00%
Accrued bonus																						7,900,000
Bonus paid																				6,600,000	5,200,000
Employer contribution percentage to retirement plan		6.00%
Employer profit-sharing contribution percentage		3.00%
Employee retirement plan expenses																							3,400,000	2,600,000	2,700,000
Health care benefits																										$ 8,800,000	$ 8,100,000	$ 6,500,000