Revenue from Contracts with Customers - Additional Information (Details) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Revenue from Contracts with Customer [Line Items]
Accounts receivable, net	[1]	$ 219,924	$ 221,164	[2]
Customers [Member]
Revenue from Contracts with Customer [Line Items]
Accounts receivable, net		$ 262,400	$ 214,300

[1] Accounts receivable, net includes amounts receivable from affiliates (as defined in Note 1) of $96.3 million and $72.6 million as of June 30, 2019, and December 31, 2018, respectively.

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