Benefit Plans (Notes)	12 Months Ended
Dec. 31, 2014
Disclosure Text Block [Abstract]
Benefit Plans	BENEFIT PLANS Certain of the benefit costs charged to us by Williams associated with employees who directly support us are described below. Additionally, allocated corporate expenses from Williams to us also include amounts related to these same employee benefits, which are not included in the amounts presented below. (See Note 7 for further discussion.) Pension and Other Postretirement Benefit Plans Williams has noncontributory defined benefit pension plans (Williams Pension Plan, Williams Inactive Employees Pension Plan, and The Williams Companies Retirement Restoration Plan) that provide pension benefits for its eligible employees. Pension cost charged to us by Williams was $4.2 million in 2014, $7.8 million in 2013, and $7.3 million in 2012. Williams provides certain retiree health care and life insurance benefits for eligible participants that generally were employed by Williams on or before December 31, 1991. During 2014 and 2013, we received credits from Williams related to retiree health care and life insurance benefits of $4.3 million and $1.7 million, respectively. The credit in 2012 was minimal. These credits were recorded as regulatory liabilities. Defined Contribution Plan Included in compensation expense is $2.0 million for 2014 and 2013 and $2.5 million for 2012 that Williams charged us for matching contributions to this plan. Employee Stock-Based Compensation Plan Information The Williams Companies, Inc. 2007 Incentive Plan, as amended and restated on February 23, 2010, (Plan) was approved by stockholders on May 20, 2010. The Plan provides for Williams’ common stock-based awards to both employees and nonmanagement directors. The Plan permits the granting of various types of awards including, but not limited to, restricted stock units and stock options. Awards may be granted for no consideration other than prior and future services or based on certain financial performance targets achieved. Williams currently bills us directly for compensation expense related to stock-based compensation awards based on the fair value of the awards. We are also billed for our proportionate share of Williams’ and other affiliates’ stock-based compensation expense through various allocation processes. Total stock-based compensation expense, included in administrative and general expenses, for the years ended December 31, 2014, 2013 and 2012 was $1.2 million, $1.2 million and $1.6 million, respectively, excluding amounts allocated from WPZ and Williams.

BENEFIT PLANS

Certain of the benefit costs charged to us by Williams associated with employees who directly support us are described below. Additionally, allocated corporate expenses from Williams to us also include amounts related to these same employee benefits, which are not included in the amounts presented below. (See Note 7 for further discussion.)

Pension and Other Postretirement Benefit Plans

Williams has noncontributory defined benefit pension plans (Williams Pension Plan, Williams Inactive Employees Pension Plan, and The Williams Companies Retirement Restoration Plan) that provide pension benefits for its eligible employees. Pension cost charged to us by Williams was $4.2 million in 2014, $7.8 million in 2013, and $7.3 million in 2012.

Williams provides certain retiree health care and life insurance benefits for eligible participants that generally were employed by Williams on or before December 31, 1991. During 2014 and 2013, we received credits from Williams related to retiree health care and life insurance benefits of $4.3 million and $1.7 million, respectively. The credit in 2012 was minimal. These credits were recorded as regulatory liabilities.

Defined Contribution Plan

Included in compensation expense is $2.0 million for 2014 and 2013 and $2.5 million for 2012 that Williams charged us for matching contributions to this plan.

Employee Stock-Based Compensation Plan Information

The Williams Companies, Inc. 2007 Incentive Plan, as amended and restated on February 23, 2010, (Plan) was approved by stockholders on May 20, 2010. The Plan provides for Williams’ common stock-based awards to both employees and nonmanagement directors. The Plan permits the granting of various types of awards including, but not limited to, restricted stock units and stock options. Awards may be granted for no consideration other than prior and future services or based on certain financial performance targets achieved.

Williams currently bills us directly for compensation expense related to stock-based compensation awards based on the fair value of the awards. We are also billed for our proportionate share of Williams’ and other affiliates’ stock-based compensation expense through various allocation processes.

Total stock-based compensation expense, included in administrative and general expenses, for the years ended December 31, 2014, 2013 and 2012 was $1.2 million, $1.2 million and $1.6 million, respectively, excluding amounts allocated from WPZ and Williams.