Investments in Non-Controlled Entities (Details) - USD ($) $ in Thousands		3 Months Ended
	Feb. 29, 2016	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Intangible Assets, Net (Excluding Goodwill)		$ 44,882		$ 1,856
Equity Method Investment, Realized Gain (Loss) on Disposal		26,900	$ 0
Change in Equity Method Investments [Roll Forward]
Investments at December 31, 2015		765,628
Additional Investment in NonControlled Entities		61,738
Other Adjustment to Equity Investment		(25,105)
Proportionate share of earnings		18,255
Amortization of excess investment and capitalized interest		(627)
Earnings of non-controlled entities		17,628	9,590
Distributions of earnings from investments in non-controlled entities		17,297	9,229
Distributions in excess of earnings of non-controlled entities		2,212	4,613
Investments at March 31, 2016		800,380
Equity Method Investment, Summarized Financial Information, Revenue		62,207	46,656
Equity Method Investment, Summarized Financial Information, Net Income (Loss)		$ 36,514	20,618
Texas Frontera Llc [Member]
Schedule of Equity Method Investments [Line Items]
Interest in equity method investment		50.00%
Saddlehorn Pipeline Company [Member]
Schedule of Equity Method Investments [Line Items]
Interest in equity method investment		40.00%
Seabrook Logistics, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Interest in equity method investment		50.00%
Osage Pipeline Co [Member]
Schedule of Equity Method Investments [Line Items]
Interest in equity method investment	50.00%
Intangible Assets, Net (Excluding Goodwill)	$ 43,700
Nontrade Receivables	$ 8,300
Finite-Lived Intangible Asset, Useful Life	20 years
Equity Method Investment, Realized Gain (Loss) on Disposal	$ 26,900
Double Eagle Pipeline Llc [Member]
Schedule of Equity Method Investments [Line Items]
Interest in equity method investment		50.00%
HoustonLink Pipeline Company LLC [Member]
Schedule of Equity Method Investments [Line Items]
Interest in equity method investment		50.00%
Powder Springs Logistics, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Interest in equity method investment		50.00%
BridgeTex [Member]
Schedule of Equity Method Investments [Line Items]
Interest in equity method investment		50.00%
Change in Equity Method Investments [Roll Forward]
Investments at December 31, 2015		$ 495,267
Additional Investment in NonControlled Entities		6,336
Other Adjustment to Equity Investment		0
Proportionate share of earnings		15,624
Amortization of excess investment and capitalized interest		(510)
Earnings of non-controlled entities		15,114
Distributions of earnings from investments in non-controlled entities		15,114
Distributions in excess of earnings of non-controlled entities		1,291
Investments at March 31, 2016		500,312
Equity Method Investment, Summarized Financial Information, Revenue		50,798	37,136
Equity Method Investment, Summarized Financial Information, Net Income (Loss)		31,248	18,037
All Other Equity Investments [Member]
Change in Equity Method Investments [Roll Forward]
Investments at December 31, 2015		270,361
Additional Investment in NonControlled Entities		55,402
Other Adjustment to Equity Investment		(25,105)
Proportionate share of earnings		2,631
Amortization of excess investment and capitalized interest		(117)
Earnings of non-controlled entities		2,514
Distributions of earnings from investments in non-controlled entities		2,183
Distributions in excess of earnings of non-controlled entities		921
Investments at March 31, 2016		300,068
Equity Method Investment, Summarized Financial Information, Revenue		11,409	9,520
Equity Method Investment, Summarized Financial Information, Net Income (Loss)		5,266	2,581
Equity Method Investee [Member] | Saddlehorn Pipeline Company [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party		400
Equity Method Investee [Member] | Seabrook Logistics, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party		100
Equity Method Investee [Member] | Double Eagle Pipeline Llc [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party		700	900
Accounts Receivable, Related Parties, Current		300		$ 200
Equity Method Investee [Member] | BridgeTex [Member]
Schedule of Equity Method Investments [Line Items]
Related Party Transaction, Other Revenues from Transactions with Related Party		$ 8,900	$ 8,400