Affiliate Transactions Affiliate Transactions (Details) (USD $)	3 Months Ended			12 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 07, 2014	Dec. 31, 2013 EnLink Midstream Holdings, LP [Member]	Mar. 31, 2014 Customer [Member]	Mar. 31, 2013 Customer [Member]	Mar. 31, 2014 Customer [Member]	Mar. 31, 2013 Customer [Member]	Mar. 31, 2014 Bridgeport [Member]	Mar. 31, 2014 Oklahoma City [Member]	Mar. 31, 2014 Cresson [Member]	Mar. 31, 2014 Continuing Operations [Member] Customer [Member]	Mar. 31, 2013 Continuing Operations [Member] Customer [Member]	Mar. 31, 2014 Discontinued Operations [Member] Customer [Member]	Mar. 31, 2013 Discontinued Operations [Member] Customer [Member]	Mar. 31, 2014 Pre-Acquisition [Member] Continuing Operations [Member] Customer [Member]	Mar. 31, 2013 Pre-Acquisition [Member] Continuing Operations [Member] Customer [Member]	Mar. 31, 2014 Post-Acquisition[Member] Continuing Operations [Member] Customer [Member]	Mar. 31, 2014 Total [Member] Customer [Member]	Mar. 31, 2013 Total [Member] Customer [Member]	Mar. 31, 2014 Total [Member] Continuing Operations [Member] Customer [Member]	Mar. 31, 2013 Total [Member] Continuing Operations [Member] Customer [Member]	Mar. 31, 2014 Total [Member] Discontinued Operations [Member] Customer [Member]	Mar. 31, 2013 Total [Member] Discontinued Operations [Member] Customer [Member]	Mar. 31, 2014 Devon Energy Corporation [Member]	Mar. 31, 2013 Devon Energy Corporation [Member]	Mar. 31, 2014 Customer [Member]	Mar. 31, 2013 Customer [Member]
Related Party Transaction [Line Items]
Revenues	$ 232,400,000	$ 41,800,000												$ (10,400,000)	$ (23,100,000)	$ (436,400,000)	$ (485,100,000)	$ 55,500,000
Operating Expenses												340,000,000	381,200,000	5,000,000	8,300,000												5,900,000	8,900,000
Net Cash Provided by (Used in) Financing Activities	248,200,000	25,200,000												0	(2,000,000)
Net Affiliate Transactions												(96,400,000)	(103,900,000)	(5,400,000)	(16,800,000)
Business Acquisition, Percentage of Voting Interests Acquired			50.00%
Capital Expenditures	67,900,000	83,200,000										21,300,000	99,900,000	600,000	2,700,000
Other transactions with related party												53,000,000	45,200,000	400,000	1,500,000
Total Third-Party Transactions												74,300,000	145,100,000	1,000,000	4,200,000
Net distributions from (to) related party					(26,500,000)	28,600,000						(22,100,000)	41,200,000	(4,400,000)	(12,600,000)				(92,600,000)	28,600,000	(48,300,000)	41,200,000	(44,300,000)	(12,600,000)
Net distributions from (to) related party, non-cash												(26,200,000)	0	(39,900,000)	0
Business Acquisition, Date of Acquisition Agreement				Mar. 07, 2014
Concentration Risk, Percentage							68.00%	92.00%
Due from Affiliate, Current	57,800,000
Cost of Share-based Compensation	4,000,000	3,100,000																							2,800,000	3,100,000
Pension and Other Postretirement Benefit Expense																									1,600,000	2,100,000
Operating Leases, Rent Expense									$ 200,000	$ 0	$ 100,000