Organization, Description of Business and Basis of Presentation (Changes from New Accounting Pronouncements) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Item Effected [Line Items]
Distributions of earnings from investments in non-controlled entities	$ 94,661	$ 57,906
Net Cash Provided by (Used in) Operating Activities	564,066	583,563
Distributions in excess of earnings of non-controlled entities		0
Net Cash Provided by (Used in) Investing Activities	(322,489)	(331,891)
Property, Plant and Equipment, Gross	7,443,095			$ 7,235,468
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(1,783,036)			(1,682,633)
Property, Plant and Equipment, Net	5,660,059			5,552,835
Investments in non-controlled entities	1,210,259			1,082,511
Deferred revenue	120,134			117,795
Other noncurrent liabilities	69,526			30,350
Limited partner unitholders	2,281,845			2,267,231
Accounting Standards Update 2014-09 [Member]
Item Effected [Line Items]
Property, Plant and Equipment, Gross	7,443,095		$ 7,243,984
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(1,783,036)		(1,682,958)
Property, Plant and Equipment, Net	5,660,059		5,561,026
Investments in non-controlled entities	1,210,259		1,083,013
Deferred revenue	120,134		115,894
Other noncurrent liabilities	69,526		34,969
Limited partner unitholders	2,281,845		2,273,206
Scenario, Previously Reported [Member]
Item Effected [Line Items]
Distributions of earnings from investments in non-controlled entities		46,754
Net Cash Provided by (Used in) Operating Activities		572,411
Distributions in excess of earnings of non-controlled entities		11,152
Net Cash Provided by (Used in) Investing Activities		(320,739)
Restatement Adjustment [Member] | Accounting Standards Update 2016-15 [Member]
Item Effected [Line Items]
Distributions of earnings from investments in non-controlled entities		11,152
Net Cash Provided by (Used in) Operating Activities		11,152
Distributions in excess of earnings of non-controlled entities		(11,152)
Net Cash Provided by (Used in) Investing Activities		$ (11,152)
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Item Effected [Line Items]
Property, Plant and Equipment, Gross	7,433,091			7,235,468
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(1,782,591)			(1,682,633)
Property, Plant and Equipment, Net	5,650,500			5,552,835
Investments in non-controlled entities	1,209,757			1,082,511
Deferred revenue	128,349			117,795
Other noncurrent liabilities	64,687			30,350
Limited partner unitholders	2,268,408			$ 2,267,231
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Item Effected [Line Items]
Property, Plant and Equipment, Gross	10,004		8,516
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(445)		(325)
Property, Plant and Equipment, Net	9,559		8,191
Investments in non-controlled entities	502		502
Deferred revenue	(8,215)		(1,901)
Other noncurrent liabilities	4,839		4,619
Limited partner unitholders	$ 13,437		$ 5,975