Equity (Tables)

3 Months Ended

Mar. 31, 2018

Schedule of Stockholders Equity [Table Text Block]

The changes in the number of units outstanding during the three months ended March 31, 2018 are summarized below:



(In units)	Common	General Partner		Total
Balance at December 31, 2017	407,130,020	8,308,773		415,438,793
Unit-based compensation awards⁽¹⁾	150,257	140		150,397
Contribution of refining logistics and fuels distribution assets⁽²⁾	111,611,111	2,277,778		113,888,889
Conversion of GP economic interests	275,000,000	(10,586,691	)	264,413,309
Balance at March 31, 2018	793,891,388	—		793,891,388


(1)	As a result of the unit-based compensation awards issued during the period, MPLX GP contributed less than $1 million in exchange for 140 general partner units to maintain its two percent GP Interest.


(2)	MPC agreed to waive approximately one-third of the first quarter 2018 distributions on the common units issued in connection with this transaction. As a result of this waiver, MPC will not receive $23.7 million of the distributions that would have otherwise accrued on such common units with respect to the first quarter 2018. See Note 4 for information regarding this acquisition.

Schedule Of Calculation Of Net Income Applicable to Partners [Table Text Block]

The following table presents the allocation of the general partner’s GP Interest in net income attributable to MPLX LP, for income statement periods occurring prior to the exchange of the GP economic interests:



	Three Months Ended March 31,
(In millions)	2017
Net income attributable to MPLX LP	$	150
Less: Preferred unit distributions	16
General partner's IDRs and other	61
Net income attributable to MPLX LP available to general and limited partners	$	73

General partner's two percent GP Interest in net income attributable to MPLX LP	$	1
General partner's IDRs and other	61
General partner's GP Interest in net income attributable to MPLX LP	$	62

Distributions Made to Limited Partner, by Distribution [Table Text Block]

The allocation of total quarterly cash distributions to general, limited and preferred unitholders is as follows for the three months ended March 31, 2018 and 2017. The Partnership’s distributions are declared subsequent to quarter end; therefore, the following table represents total cash distributions applicable to the period in which the distributions were earned.



	Three Months Ended March 31,
(In millions)	2018		2017
General partner's distributions:
General partner's distributions on general partner units	$	—	$	5
General partner's distributions on IDRs	—		60
Total distribution on general partner units and IDRs	$	—	$	65
Common and preferred unit distributions:
Common unitholders, includes common units of general partner	$	467	$	198
Preferred unit distributions	16		16
Total cash distributions declared	$	483	$	279