Partners' Capital Partner's Capital (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Capital Unit [Line Items]
Limited Partners' Cash Distributions Rights Period	45 days
Limited Partners' Ownership Percentage Threshold, Event of Voting Exclusion	20.00%
General Partners' Ownership Percentage Threshold, Event of Units Sale by Limited Parnters to General Parnters	80.00%
Limited Partners' Minimum Vote Required for Removal of General Partner	66.66%
Investor
Capital Unit [Line Items]
Common units outstanding (in shares)	61,110,374
Affiliated Entity
Capital Unit [Line Items]
Common units outstanding (in shares)	16,449,981
Limited Partners
Capital Unit [Line Items]
Limited partners interest units outstanding	77,560,355	77,177,159