Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities:
Net income	$ 210,910	$ 222,736
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	51,879	47,298
Loss (gain) on sale and retirement of assets	1,997	3,461
Earnings of non-controlled entities	(34,538)	(21,446)
Distributions of earnings from investments in non-controlled entities	51,754	21,605
Equity-based incentive compensation expense	6,632	4,147
Settlement cost, amortization of prior service credit and actuarial loss	5,069	2,548
Changes in operating assets and liabilities:
Trade accounts receivable and other accounts receivable	23,371	33,988
Inventory	(13,642)	(12,050)
Energy commodity derivatives contracts, net of derivatives deposits	617	8,713
Accounts payable	19,457	7,275
Accrued payroll and benefits	(26,544)	(17,766)
Accrued interest payable	(17,956)	(23,391)
Accrued taxes other than income	(16,721)	(10,176)
Accrued product liabilities	(10,893)	(13,807)
Deferred revenue	1,463	5,590
Current and noncurrent environmental liabilities	(359)	540
Other current and noncurrent assets and liabilities	25,406	7,618
Net cash provided by operating activities	277,902	266,883
Investing Activities:
Additions to property, plant and equipment, net	(99,471)	(141,515)
Proceeds from sale and disposition of assets	214	3,368
Investments in non-controlled entities	(60,976)	(44,511)
Distributions in excess of earnings of non-controlled entities		0
Net cash used by investing activities	(160,233)	(182,658)
Financing Activities:
Distributions paid	(209,940)	(194,961)
Net commercial paper borrowings	0	116,965
Debt placement costs	(315)	0
Payments associated with settlement of equity-based incentive compensation	(9,285)	(13,875)
Net cash used by financing activities	(219,540)	(91,871)
Change in cash and cash equivalents	(101,871)	(7,646)
Cash and cash equivalents at beginning of period	176,068	14,701
Cash and cash equivalents at end of period	74,197	7,055
Supplemental non-cash investing and financing activities:
Issuance of limited partner units in settlement of equity-based incentive plan awards	120	1,669
Additions to property, plant and equipment	(105,384)	(142,635)
Changes in accounts payable and other current liabilities related to capital expenditures	5,913	1,120
Additions to property, plant and equipment, net	$ (99,471)	$ (141,515)