Gas Gathering Divestiture	3 Months Ended
Mar. 31, 2013
Gas Gathering Divestiture [Abstract]
Gas Gathering Divestiture [Text Block]	Gas Gathering Divestiture Texas Panhandle Gathering Divestiture As previously reported in the Company's 2012 Form 10-K, on January 2, 2013, Enogex and one of its five largest customers entered into new agreements, effective January 1, 2013, relating to the customer's gathering and processing volumes on the Texas portion of Enogex's system. The effects of this new arrangement are (i) a fixed-fee processing agreement replaced the previous keep-whole agreement, (ii) the acreage dedicated by the customer to Enogex for gathering and processing in Texas was increased for an extended term and (iii) the sale by Enogex of certain gas gathering assets in the Texas Panhandle portion of Enogex's system to this customer for cash proceeds of approximately $35 million. Enogex recognized a pre-tax gain of $9.9 million in the first quarter of 2013 in its natural gas gathering and processing segment from the sale of these assets which is included in Other Income in the Condensed Consolidated Statements of Income.

Gas Gathering Divestiture

Texas Panhandle Gathering Divestiture

As previously reported in the Company's 2012 Form 10-K, on January 2, 2013, Enogex and one of its five largest customers entered into new agreements, effective January 1, 2013, relating to the customer's gathering and processing volumes on the Texas portion of Enogex's system. The effects of this new arrangement are (i) a fixed-fee processing agreement replaced the previous keep-whole agreement, (ii) the acreage dedicated by the customer to Enogex for gathering and processing in Texas was increased for an extended term and (iii) the sale by Enogex of certain gas gathering assets in the Texas Panhandle portion of Enogex's system to this customer for cash proceeds of approximately $35 million. Enogex recognized a pre-tax gain of $9.9 million in the first quarter of 2013 in its natural gas gathering and processing segment from the sale of these assets which is included in Other Income in the Condensed Consolidated Statements of Income.