Note 2 - Acquisitions Predecessor Reconciliation (Details) - USD ($) $ in Millions		3 Months Ended																12 Months Ended
		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Revenues		$ 623		$ 642	[1]	$ 569	[1]	$ 546	[1]	$ 1,114	[1]	$ 1,094	[1]	$ 614	[1]	$ 427	[1]	$ 2,380	[2]	$ 3,249	[2]	$ 1,669	[2]
Operating expenses		227		236	[1]	221	[1]	201	[1]	179	[1]	199	[1]	171	[1]	142	[1]	885	[1],[2]	691	[1],[2]	560	[2]
General and Administrative Expense	[2]																	121		158		106
Depreciation and amortization expenses	[3]																	368		313		233	[4]
(Gain) loss on asset disposals and impairments	[2]																	4		(25)		4	[3]
Operating Income		224		215	[1]	180	[1]	177	[1]	179	[1]	147	[1]	146	[1]	131	[1]	796	[2]	603	[2]	448	[2]
Interest and financing costs, net	[2]																	(233)		(330)		(195)
Equity in earnings of equity method investments	[2]																	31		22		13
Other Income, net	[2]																	6		11		11
Net Earnings		171		166	[1]	132	[1]	131	[1]	53	[1]	90	[1]	90	[1]	73	[1]	600	[2],[4],[5]	306	[2],[4],[5]	277	[2],[3],[4],[5]
Net Income (Loss) Attributable To Predecessors																		28		43		62
Net Earnings Attributable to Partners																		628		349		339
Noncontrolling Interest in Net Income (Loss) Preferred Unit Holders, Redeemable																		(44)		(3)		0
Net Income (Loss) Allocated to General Partners																		0		(79)		(152)
Limited partners’ interest in net earnings		161		160		138		125		47	[6]	97	[6]	70	[6]	55	[6]	584		267		187
Oil and Gas, Purchased [Member]
Cost of Goods and Services Sold										528	[7],[8]	554	[7],[8]	162	[7],[8]	0	[7],[8]	0	[2],[9]	1,244	[2],[7],[8],[9]	316	[2],[9]
Natural Gas, Midstream [Member]
Cost of Goods and Services Sold		$ 40	[8]	$ 73	[8]	$ 45	[8]	$ 48	[8]	$ 86	[8]	$ 64	[8]	$ 56	[8]	$ 59	[8]	206	[2]	265	[2],[8]	2	[2]
Affiliated Entity [Member]
Revenues																		1,589		1,431		847
Affiliated Entity [Member] | Fee-Based Sales [Member]
Revenues	[2]																	1,309		942		747
Affiliated Entity [Member] | Product-Based Sales [Member]
Revenues	[2],[9]																	280		489		100
Third Party [Member] | Fee-Based Sales [Member]
Revenues	[2]																	591		656		819
Third Party [Member] | Product-Based Sales [Member]
Revenues	[2],[9]																	200		1,162		3
Successor [Member]
Revenues	[2]																	2,350		2,151		1,220
Operating expenses																		845	[1]	554	[1]	426	[2]
General and Administrative Expense	[2]																	112		121		94
Depreciation and amortization expenses	[3]																	346		255		183
(Gain) loss on asset disposals and impairments	[2]																	4		(24)		4
Operating Income	[2]																	837		650		511
Interest and financing costs, net	[2]																	(229)		(321)		(196)
Equity in earnings of equity method investments	[2]																	15		10		13
Other Income, net	[2]																	5		10		11
Net Earnings																		628	[4]	349	[4]	339	[2]
Net Income (Loss) Attributable To Predecessors																		0		0		0
Net Earnings Attributable to Partners																		628		349		339
Noncontrolling Interest in Net Income (Loss) Preferred Unit Holders, Redeemable																		(44)		(3)
Net Income (Loss) Allocated to General Partners																				(79)		(152)
Limited partners’ interest in net earnings																		584		267		187
Successor [Member] | Oil and Gas, Purchased [Member]
Cost of Goods and Services Sold	[2],[9]																			330		0
Successor [Member] | Natural Gas, Midstream [Member]
Cost of Goods and Services Sold	[2]																	206		265		2
Successor [Member] | Affiliated Entity [Member] | Fee-Based Sales [Member]
Revenues	[2]																	1,288		796		615
Successor [Member] | Affiliated Entity [Member] | Product-Based Sales [Member]
Revenues	[2],[9]																	280		213		100
Successor [Member] | Third Party [Member] | Fee-Based Sales [Member]
Revenues	[2]																	582		647		502
Successor [Member] | Third Party [Member] | Product-Based Sales [Member]
Revenues	[2],[9]																	200		495		3
Predecessor [Member]
Revenues	[2]																	30		1,098		449
Operating expenses																		40	[1]	137	[1]	134	[2]
General and Administrative Expense	[2]																	9		37		12
Depreciation and amortization expenses	[3]																	22		58		50
(Gain) loss on asset disposals and impairments	[2]																	0		(1)		0
Operating Income	[2]																	(41)		(47)		(63)
Interest and financing costs, net	[2]																	(4)		(9)		1
Equity in earnings of equity method investments	[2]																	16		12		0
Other Income, net	[2]																	1		1		0
Net Earnings																		(28)	[4]	(43)	[4]	(62)	[2]
Net Income (Loss) Attributable To Predecessors																		28		43		62
Net Earnings Attributable to Partners																		0		0		0
Noncontrolling Interest in Net Income (Loss) Preferred Unit Holders, Redeemable																		0		0
Net Income (Loss) Allocated to General Partners																				0		0
Limited partners’ interest in net earnings																		0		0		0
Predecessor [Member] | Oil and Gas, Purchased [Member]
Cost of Goods and Services Sold	[2],[9]																			914		316
Predecessor [Member] | Natural Gas, Midstream [Member]
Cost of Goods and Services Sold	[2]																	0		0		0
Predecessor [Member] | Affiliated Entity [Member] | Fee-Based Sales [Member]
Revenues	[2]																	21		146		132
Predecessor [Member] | Affiliated Entity [Member] | Product-Based Sales [Member]
Revenues	[2],[9]																	0		276		0
Predecessor [Member] | Third Party [Member] | Fee-Based Sales [Member]
Revenues	[2]																	9		9		317
Predecessor [Member] | Third Party [Member] | Product-Based Sales [Member]
Revenues	[2],[9]																	$ 0		$ 667		$ 0

[1] Adjusted to include the historical results of the Predecessors. See Notes 1 and 2 for further discussion.

[2] All periods include the historical results of the Predecessors. See Notes 1 and 2 for further discussion.

[3] All periods include the historical results of the Predecessors. See Notes 1 and 2 for further discussion.

[4] Adjusted to include the historical results of the Predecessors. See Notes 1 and 2 for further discussion.

[5] Adjusted to include the historical results of the Predecessors. See Notes 1 and 2 for further discussion.

[6] The sum of four quarters may not equal annual results due to rounding or the quarterly number of units outstanding.

[7] Due to the adoption of ASC 606 effective January 1, 2018, the revenues and costs associated with our fuel purchase and supply arrangements for the year ended December 31, 2018 were netted. See Note 1 for further discussion.

[8] Excludes direct operating expenses incurred across our operating segments and depreciation and amortization expenses.

[9] Due to the adoption of ASC 606 effective January 1, 2018, the revenues and costs associated with our fuel purchase and supply arrangements for year ended December 31, 2018 were netted. See Note 1 for further discussion.