Distributions and Net Income Per Limited Partner Unit (Income In Excess Of Distribution) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Net income attributable to the Partnership	$ 18,535	$ 14,922	$ 51,142	$ 43,610
Distributions declared	16,591	16,348	49,772	48,127
Net income in excess of distribution (distribution in excess of net income)	1,944	(1,426)	1,370	(4,517)
IDR Holders [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Net income attributable to the Partnership	0	0	0	0
Distributions declared with respect to the incentive distribution rights	0	0	0	0
Net income in excess of distribution (distribution in excess of net income)	0	0	0	0
Common units [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Net income attributable to the Partnership	18,535	14,922	51,142	43,610
Distributions declared	16,591	16,348	49,772	48,127
Net income in excess of distribution (distribution in excess of net income)	1,944	(1,426)	1,370	(4,517)
Cash Distribution [Member] | Common units [Member]
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Distributions declared	$ 16,591	$ 16,348	$ 49,772	$ 48,127