Acquisitions Acquisitions - Impact to Historical Consolidated Statement of Income Table (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Revenues	$ 279,457		$ 225,766	[1]
Equity income, net	9,251	[2],[3]	3,968	[1],[2],[3]
Net income	90,175		51,733	[1]
Historical [Member]
Revenues			225,766
Equity income, net			3,981
Net income			51,676
Texas Express And Front Range [Member]
Revenues			0
Equity income, net			(13)
Net income			$ 57

[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.