Acquisitions Acquisitions - Impact to Historical Consolidated Statement of Income Table (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Revenues	$ 329,944		$ 251,402	[1]	$ 609,401		$ 477,168	[1]
Equity income, net	13,008	[2]	3,456	[1],[2]	22,259	[2],[3]	7,424	[1],[2],[3]
Net income	97,746		60,949	[1]	187,921		112,682	[1]
Historical [Member]
Revenues			251,402				477,168
Equity income, net			3,724				7,705
Net income			61,133				112,809
Texas Express And Front Range [Member]
Revenues			0				0
Equity income, net			(268)				(281)
Net income			$ (184)				$ (127)

[1] Financial information has been recast to include the financial position and results attributable to the TEFR Interests. See Note 1 and Note 2.

[2] Income earned from equity investments is classified as affiliate. See Note 1.

[3] Income earned on, distributions from and contributions to equity investments are classified as affiliate. See Note 1.