Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 137,821	$ 102,999	$ 231,345	$ 193,064
Other comprehensive income:
Net gain on interest rate cash flow hedges	1,008		1,008
Net gain on commodity cash flow hedges	1,667	4,613	1,667	4,613
Reclassification of net gain on interest rate cash flow hedges to interest expense	(41)	(41)	(82)	(82)
Amortization of prior service credit and actuarial loss	853	77	1,705	155
Total other comprehensive income	3,487	4,649	4,298	4,686
Comprehensive income	141,308	107,648	235,643	197,750
Comprehensive loss attributable to non-controlling owners' interest in consolidated subsidiaries				(63)
Comprehensive income attributable to partners' capital	$ 141,308	$ 107,648	$ 235,643	$ 197,813