Revenue from Contract with Customers (Schedule of Prospective Adoption) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
Item Effected [Line Items]
Transportation and terminals revenue	$ 431,937	$ 392,671
Depreciation and amortization	51,879	$ 47,298
Property, Plant and Equipment, Gross	7,346,495			$ 7,235,468
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	1,732,486			1,682,633
Property, Plant and Equipment, Net	5,614,009			5,552,835
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	1,126,773			1,082,511
Deferred revenue	119,258			117,795
Other noncurrent liabilities	34,764			30,350
Limited partner unitholders	2,271,486			2,267,231
Accounting Standards Update 2014-09 [Member]
Item Effected [Line Items]
Transportation and terminals revenue	431,937
Depreciation and amortization	51,879
Property, Plant and Equipment, Gross	7,346,495		$ 7,243,984
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	1,732,486		1,682,958
Property, Plant and Equipment, Net	5,614,009		5,561,026
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	1,126,773		1,083,013
Deferred revenue	119,258		115,894
Other noncurrent liabilities	34,764		34,969
Limited partner unitholders	2,271,486		2,273,206
Accounting Standards Update 2014-09 [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Item Effected [Line Items]
Transportation and terminals revenue	431,524
Depreciation and amortization	51,823
Property, Plant and Equipment, Gross	7,336,491			7,235,468
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	1,732,105			1,682,633
Property, Plant and Equipment, Net	5,604,386			5,552,835
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	1,126,271			1,082,511
Deferred revenue	120,814			117,795
Other noncurrent liabilities	29,415			30,350
Limited partner unitholders	2,265,511			$ 2,267,231
Accounting Standards Update 2014-09 [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Item Effected [Line Items]
Transportation and terminals revenue	413
Depreciation and amortization	56
Property, Plant and Equipment, Gross	10,004		8,516
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	381		325
Property, Plant and Equipment, Net	9,623		8,191
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	502		502
Deferred revenue	(1,556)		(1,901)
Other noncurrent liabilities	5,349		4,619
Limited partner unitholders	$ 5,975		$ 5,975