Accounts Receivable - Third Parties (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade customers	$ 22,245	$ 37,514
Allowance for doubtful accounts	(170)	0
Receivables from trade customers and affiliates, net	22,075	37,514
Other	0	6
Accounts receivable, net - third parties	$ 22,075	$ 37,520