Partners' Equity, Cash Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Partners' Capital [Abstract]
Dividends Payable, Date Declared	Jul. 22, 2016
Dividends Payable, Date of Record	Aug. 01, 2016
Dividends Payable, Date to be Paid	Aug. 12, 2016
Allocations of Quarterly Cash Distributions to General and Limited Partners
Partners' Capital, Distribution Amount Per Share	$ 0.585		$ 0.585
Partner Distributions
General partner interest	$ 978	$ 877	$ 1,927	$ 1,738
General partner incentive distribution	12,137	9,784	23,609	19,145
Total general partner distribution	13,115	10,661	25,536	20,883
Limited partner distribution	34,575	31,968	68,302	63,496
Quarterly Cash Distributions	$ 47,690	$ 42,629	$ 93,838	$ 84,379
Cash distribution per unit applicable to limited partners	$ 0.5850	$ 0.5450	$ 1.1600	$ 1.0825