Distributions To Unitholders (Details) - $ / shares			3 Months Ended					9 Months Ended
	May 31, 2017	Feb. 28, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2017
Common Units
Distribution paid per unit			$ 0.4508	$ 0.4441	$ 0.4375	$ 0.4310	$ 0.4246
Aggregate distribution of units								393,291
Class B Preferred
Distribution paid per unit			$ 0.28225	$ 0.28225	$ 0.2258	$ 0.2258	$ 0.4500
Aggregate distribution of units	184,697	208,594