Partners' Capital and Distributions Partners' Capital and Distributions (Schedule of Capital Units) (Details)	6 Months Ended
	Jun. 30, 2017 shares
Increase (Decrease) in Partners' Capital [Roll Forward]
Limited partner units outstanding on January 1, 2017	227,783,916
Limited partner units outstanding on June 30, 2017	228,024,556
Management [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' Capital Account, Units, Unit-based Compensation	216,679
Director [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' Capital Account, Units, Unit-based Compensation	23,961