Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues	$ 598,264	$ 656,596	$ 1,841,478	$ 1,987,230
Costs and expenses:
Operating	161,982	169,387	457,597	484,341
Cost of product sales	96,119	108,757	395,864	430,727
Depreciation, amortization and impairment	71,822	56,627	193,896	181,028
General and administrative	38,016	51,156	117,092	149,534
Total costs and expenses	367,939	385,927	1,164,449	1,245,630
Other operating income (expense)	(2,863)	(379)	539	1,538
Earnings of non-controlled entities	39,135	50,189	116,484	122,229
Operating profit	266,597	320,479	794,052	865,367
Interest expense	54,212	53,750	179,371	165,322
Interest capitalized	(1,272)	(5,831)	(10,451)	(14,419)
Interest income	(260)	(648)	(903)	(2,646)
Gain on disposition of assets	0	(2,532)	(12,887)	(28,966)
Other (income) expense	1,455	2,602	3,708	9,222
Income before provision for income taxes	212,462	273,138	635,214	736,854
Provision for income taxes	824	100	2,169	2,450
Net income	$ 211,638	$ 273,038	$ 633,045	$ 734,404
Basic net income per common unit (in dollars per share)	$ 0.94	$ 1.19	$ 2.80	$ 3.21
Diluted net income per common unit (in dollars per share)	$ 0.94	$ 1.19	$ 2.80	$ 3.21
Weighted average number of common units outstanding used for basic net income per unit calculation (in shares)	225,222	228,720	226,045	228,642
Weighted average number of common units outstanding used for diluted net income per unit calculation (in shares)	225,222	228,754	226,045	228,667
Service [Member]
Revenues	$ 473,531	$ 506,432	$ 1,343,741	$ 1,473,629
Product [Member]
Revenues	119,445	144,807	481,842	497,791
Product and Service, Other [Member]
Revenues	$ 5,288	$ 5,357	$ 15,895	$ 15,810