Distributions and Net Income Per Limited Partner Unit (Income In Excess Of Distribution) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Net income attributable to the Partnership	$ 12,295	$ 9,764
Distributions declared	13,547	9,834
Distribution in excess of net income	(1,252)	(70)
IDR Holders [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Net income attributable to the Partnership	733	231
Distributions declared with respect to the incentive distribution rights	733	231
Distribution in excess of net income	0	0
Common units [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Net income attributable to the Partnership	11,562	5,064
Distributions declared	12,814	5,101
Distribution in excess of net income	(1,252)	(37)
Subordinated units [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Net income attributable to the Partnership		4,469
Distributions declared		4,502
Distribution in excess of net income		(33)
Cash Distribution [Member] | IDR Holders [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Distributions declared with respect to the incentive distribution rights	733	231
Cash Distribution [Member] | Common units [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Distributions declared	12,814	5,101
Cash Distribution [Member] | Subordinated units [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Distributions declared	$ 0	$ 4,502