Equity - Cash Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands							3 Months Ended
	May 12, 2020	Feb. 12, 2020	Nov. 12, 2019	Aug. 13, 2019	May 14, 2019	Feb. 12, 2019	Mar. 31, 2020	Mar. 31, 2019
Distribution Made to Limited Partner [Line Items]
Total Quarterly Distribution Per Limited Partner Unit - Paid (in dollars per share)		$ 0.885	$ 0.880	$ 0.850	$ 0.820
Total Quarterly Distribution Per Limited Partner Unit, Annualized - Paid (in dollars per share)		$ 3.54	$ 3.52	$ 3.40	$ 3.28
Total Cash Distribution, including general partner interest and IDRs		$ 30,634	$ 30,379	$ 28,914	$ 27,438	$ 26,900
Total Quarterly Distribution Per Limited Partner Unit - Declared (in dollars per share)							$ 0.890	$ 0.820
Subsequent Event
Distribution Made to Limited Partner [Line Items]
Total Quarterly Distribution Per Limited Partner Unit - Paid (in dollars per share)	$ 0.890
Total Quarterly Distribution Per Limited Partner Unit, Annualized - Paid (in dollars per share)	$ 3.56
Total Cash Distribution, including general partner interest and IDRs	$ 30,878