Partnership Capital and Distributions	6 Months Ended
Jun. 30, 2013
Partnership Capital and Distributions	2. Partnership Capital and Distributions The partnership agreement requires that, within 45 days after the end of each quarter, the Partnership distribute its available cash (as defined in the partnership agreement) to unitholders of record on the applicable record date. During the three and six-month periods ended June 30, 2013, the Partnership paid cash distributions to its unitholders of approximately $93.3 million and $177.4 million, respectively, representing a $0.45 per-unit distribution for the three-month period ended December 31, 2012 and a $0.4675 per-unit distribution for the three-month period ended March 31, 2013. See also Note 10 — Subsequent Events, concerning distributions declared on July 24, 2013, for the three-month period ended June 30, 2013. General Partner Interest and Incentive Distribution Rights The general partner of the Partnership is currently entitled to two percent of all quarterly distributions that the Partnership makes. Upon the issuance of any equity by the Partnership, the general partner has the right, but not the obligation, to contribute a proportionate amount of capital to the Partnership to maintain its current general partner interest. The general partner’s initial two percent interest in the Partnership’s distributions may be reduced if the Partnership issues additional limited partner interests in the future (other than the issuance of common units upon conversion of outstanding subordinated, Class B or Class C units or the issuance of common units upon a reset of the incentive distribution rights (“IDRs”)) and its general partner does not contribute a proportionate amount of capital to the Partnership to maintain its two percent general partner interest. The general partner holds IDRs that entitle it to receive increasing percentages, up to a maximum of 50 percent, of Partnership cash distributions if any of the Partnership’s quarterly distributions exceed a specified threshold. The maximum distribution sharing percentage of 50 percent includes distributions paid to the general partner on its two percent general partner interest and assumes that the general partner maintains its general partner interest at two percent. The maximum distribution of 50 percent does not include any distributions that the general partner may receive on the limited partner units that it may acquire. Subordinated Units As of June 30, 2013, all subordinated units are held indirectly by the GIP II Entities and Williams, collectively. These units are considered subordinated because for a period of time (the “Subordination Period”), the subordinated units will not be entitled to receive any distributions until the common units have received the minimum quarterly distribution of $0.3375 per common unit plus any arrearages from prior quarters. Arrearages do not apply to and therefore will not be paid on the subordinated units. The effect of the subordinated units is to increase the likelihood that, during the Subordination Period, available cash is sufficient to fully fund cash distributions on the common units in an amount equal to or greater than the minimum quarterly distribution. The Subordination Period will lapse at such time when the Partnership has earned and paid at least the minimum quarterly distribution on each common unit, subordinated unit and general partner unit for any three consecutive, non-overlapping four-quarter periods ending on or after June 30, 2013. Also, if the Partnership has earned and paid at least 150 percent of the minimum quarterly distribution on each outstanding common unit, subordinated unit and general partner unit and the related distribution on the incentive distribution rights in a consecutive four-quarter period, the Subordination Period will terminate. Class B Units The Class B units are not entitled to cash distributions. Instead, prior to conversion into common units, the Class B units will receive quarterly distributions of additional paid-in-kind Class B units. The amount of each quarterly distribution per Class B unit will be the quotient of the quarterly distribution paid in respect of a common unit divided by the volume-weighted average price of the common units for the 30-day period prior to the declaration of the quarterly distribution to common units. Effective on the business day after the record date for the distribution on common units for the fiscal quarter ending December 31, 2014, each Class B unit will become convertible at the election of either the holder of such Class B unit or the Partnership into a common unit on a one-for-one basis. In the event of the Partnership’s liquidation, the holder of Class B units will be entitled to receive out of the Partnership’s assets available for distribution to the partners the positive balance in each such holder’s capital account in respect of such Class B units, determined after allocating the Partnership’s net income or net loss among the partners. All Class B units are held indirectly by affiliates of the Partnership’s general partner. Class C Units The Class C units are entitled to quarterly cash distributions after the common units have received the minimum quarterly distribution plus any arrearages from prior quarters. The Class C units will participate pro rata thereafter with all outstanding subordinated units until the subordinated units and Class C units receive the minimum quarterly distribution, after which the Class C units will participate in further cash distributions pro rata with the Partnership’s common units. Effective on the business day after the record date for the distribution on common units for the fiscal quarter ending December 31, 2013, each Class C unit will become convertible into a common unit on a one-for-one basis at the election of either the holder of such Class C unit or the Partnership. In the event of the Partnership’s liquidation, the holder of Class C units will be entitled to receive out of the Partnership’s assets available for distribution to the partners the positive balance in each such holder’s capital account in respect of such Class C units, determined after allocating the Partnership’s net income or net loss among the partners. All Class C units are held indirectly by affiliates of the Partnership’s general partner.

2. Partnership Capital and Distributions

The partnership agreement requires that, within 45 days after the end of each quarter, the Partnership distribute its available cash (as defined in the partnership agreement) to unitholders of record on the applicable record date. During the three and six-month periods ended June 30, 2013, the Partnership paid cash distributions to its unitholders of approximately $93.3 million and $177.4 million, respectively, representing a $0.45 per-unit distribution for the three-month period ended December 31, 2012 and a $0.4675 per-unit distribution for the three-month period ended March 31, 2013. See also Note 10 — Subsequent Events, concerning distributions declared on July 24, 2013, for the three-month period ended June 30, 2013.

General Partner Interest and Incentive Distribution Rights

The general partner of the Partnership is currently entitled to two percent of all quarterly distributions that the Partnership makes. Upon the issuance of any equity by the Partnership, the general partner has the right, but not the obligation, to contribute a proportionate amount of capital to the Partnership to maintain its current general partner interest. The general partner’s initial two percent interest in the Partnership’s distributions may be reduced if the Partnership issues additional limited partner interests in the future (other than the issuance of common units upon conversion of outstanding subordinated, Class B or Class C units or the issuance of common units upon a reset of the incentive distribution rights (“IDRs”)) and its general partner does not contribute a proportionate amount of capital to the Partnership to maintain its two percent general partner interest.

The general partner holds IDRs that entitle it to receive increasing percentages, up to a maximum of 50 percent, of Partnership cash distributions if any of the Partnership’s quarterly distributions exceed a specified threshold. The maximum distribution sharing percentage of 50 percent includes distributions paid to the general partner on its two percent general partner interest and assumes that the general partner maintains its general partner interest at two percent. The maximum distribution of 50 percent does not include any distributions that the general partner may receive on the limited partner units that it may acquire.

Subordinated Units

As of June 30, 2013, all subordinated units are held indirectly by the GIP II Entities and Williams, collectively. These units are considered subordinated because for a period of time (the “Subordination Period”), the subordinated units will not be entitled to receive any distributions until the common units have received the minimum quarterly distribution of $0.3375 per common unit plus any arrearages from prior quarters. Arrearages do not apply to and therefore will not be paid on the subordinated units. The effect of the subordinated units is to increase the likelihood that, during the Subordination Period, available cash is sufficient to fully fund cash distributions on the common units in an amount equal to or greater than the minimum quarterly distribution.

The Subordination Period will lapse at such time when the Partnership has earned and paid at least the minimum quarterly distribution on each common unit, subordinated unit and general partner unit for any three consecutive, non-overlapping four-quarter periods ending on or after June 30, 2013. Also, if the Partnership has earned and paid at least 150 percent of the minimum quarterly distribution on each outstanding common unit, subordinated unit and general partner unit and the related distribution on the incentive distribution rights in a consecutive four-quarter period, the Subordination Period will terminate.

Class B Units

The Class B units are not entitled to cash distributions. Instead, prior to conversion into common units, the Class B units will receive quarterly distributions of additional paid-in-kind Class B units. The amount of each quarterly distribution per Class B unit will be the quotient of the quarterly distribution paid in respect of a common unit divided by the volume-weighted average price of the common units for the 30-day period prior to the declaration of the quarterly distribution to common units. Effective on the business day after the record date for the distribution on common units for the fiscal quarter ending December 31, 2014, each Class B unit will become convertible at the election of either the holder of such Class B unit or the Partnership into a common unit on a one-for-one basis. In the event of the Partnership’s liquidation, the holder of Class B units will be entitled to receive out of the Partnership’s assets available for distribution to the partners the positive balance in each such holder’s capital account in respect of such Class B units, determined after allocating the Partnership’s net income or net loss among the partners. All Class B units are held indirectly by affiliates of the Partnership’s general partner.

Class C Units

The Class C units are entitled to quarterly cash distributions after the common units have received the minimum quarterly distribution plus any arrearages from prior quarters. The Class C units will participate pro rata thereafter with all outstanding subordinated units until the subordinated units and Class C units receive the minimum quarterly distribution, after which the Class C units will participate in further cash distributions pro rata with the Partnership’s common units. Effective on the business day after the record date for the distribution on common units for the fiscal quarter ending December 31, 2013, each Class C unit will become convertible into a common unit on a one-for-one basis at the election of either the holder of such Class C unit or the Partnership. In the event of the Partnership’s liquidation, the holder of Class C units will be entitled to receive out of the Partnership’s assets available for distribution to the partners the positive balance in each such holder’s capital account in respect of such Class C units, determined after allocating the Partnership’s net income or net loss among the partners. All Class C units are held indirectly by affiliates of the Partnership’s general partner.