Partners' Capital And Distributions (Distributions) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Jun. 30, 2012		Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011
Partners' Capital Notes [Abstract]
Date Paid	August 14, 2012	[1]	May 15, 2012	February 14, 2012	November 14, 2011	August 12, 2011	May 13, 2011
Per Unit Amount	$ 0.4600		$ 0.4500	$ 0.4400	$ 0.4275	$ 0.4150	$ 0.4075
Total Amount	$ 36,554		$ 35,759	$ 31,677	$ 30,777	$ 29,878	$ 26,343

[1] (1) This distribution will be paid to unitholders of record as of August 1, 2012.