Transactions with Affiliates - Affiliate Asset Contributions and Distributions Table (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	[1]	Sep. 30, 2019	Sep. 30, 2018
Related Party Transaction [Line Items]
Partners’ capital adjustment	$ 58,835		$ 0	$ 58,835	[1]
Purchases [Member] | Affiliates [Member]
Related Party Transaction [Line Items]
Cash consideration - purchases			0	(254)
Net carrying value			0	59,089
Partners’ capital adjustment			$ 0	$ 58,835

[1] Financial information has been recast to include the financial position and results attributable to AMA. See Note 1 and Note 3.