Subsequent Event
12 Months Ended
Dec. 31, 2015
Subsequent Events [Abstract]  
Subsequent Event
Subsequent Events
Partnership Distribution. On January 29, 2016, the board of directors of MLP GP, the Partnership's general partner, declared a quarterly cash distribution for the period October 1, 2015, through December 31, 2015, of $0.1800 per unit, or $18.1 million in total. This distribution is payable on February 19, 2016, to unitholders of record as of February 11, 2016.
Columbia OpCo Distribution. On February 16, 2016, Columbia OpCo distributed $129.2 million of earnings to limited partners. The Partnership received a distribution of $20.3 million and CEG received $108.9 million based on the respective ownership percentages in Columbia OpCo.