Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities:
Net income	$ 1,036,400	$ 982,000	$ 817,000
Adjustments to reconcile net income to net cash provided by operating activities:
Income from discontinued operations	(177,200)	(49,700)	(28,900)
Depreciation, amortization and impairment expense	292,800	227,900	243,100
Gain on disposition of assets	(900)	(75,000)	(12,900)
Earnings of non-controlled entities	(147,400)	(154,400)	(153,300)
Distributions from operations of non-controlled entities	174,700	193,300	207,600
Equity-based incentive compensation expense	38,500	21,800	12,000
Settlement cost, amortization of prior service credit and actuarial loss	13,900	8,400	6,700
Debt extinguishment costs	0	0	12,900
Changes in operating assets and liabilities (Note 9)	(113,000)	(9,700)	(37,100)
Net cash provided by operating activities of continuing operations	1,117,800	1,144,600	1,067,100
Net cash provided by operating activities of discontinued operations	23,500	51,600	40,400
Net cash provided by operating activities	1,141,300	1,196,200	1,107,500
Investing Activities:
Additions to property, plant and equipment, net	(175,300)	(148,600)	(424,100)
Proceeds from disposition of assets	400	275,100	334,800
Investments in non-controlled entities	(900)	(5,600)	(95,100)
Distributions from returns of investments in non-controlled entities	2,500	0	500
Net cash provided (used) by investing activities of continuing operations	(173,300)	120,900	(183,900)
Net cash provided (used) by investing activities of discontinued operations	447,700	(2,800)	(15,500)
Net cash provided (used) by investing activities	274,400	118,100	(199,400)
Financing Activities:
Distributions paid	(870,000)	(906,400)	(927,100)
Repurchases of common units, net(2)	(462,900)	(523,100)	(276,900)
Net commercial paper borrowings (repayments)	(76,000)	108,000	0
Borrowings under long-term notes	0	0	828,400
Payments on notes	0	0	(550,000)
Debt placement costs	0	0	(7,600)
Debt extinguishment costs	0	0	(12,900)
Net payment on financial derivatives	0	0	(9,500)
Payments associated with settlement of equity-based incentive compensation	(8,900)	(6,200)	(14,700)
Net cash used by financing activities	(1,417,800)	(1,327,700)	(970,300)
Change in cash, cash equivalents and restricted cash	(2,100)	(13,400)	(62,200)
Cash, cash equivalents and restricted cash at beginning of period	9,000	22,400	84,600
Cash, cash equivalents and restricted cash at end of period	6,900	9,000	22,400
Supplemental non-cash investing and financing activities:
Additions to property, plant and equipment	(168,000)	(140,800)	(344,400)
Changes in current liabilities related to capital expenditures	(7,300)	(7,800)	(79,700)
Additions to property, plant and equipment, net	(175,300)	(148,600)	(424,100)
(2) Repurchases of common units	(472,300)	(523,100)	(276,900)
Changes in accounts payable related to repurchases of common units	$ 9,400	$ 0	$ 0