Supplemental Cash Flow Information - Operating assets and liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Components of operating assets and liabilities
Decrease (increase) in restricted cash	$ 1	$ 6,766
Decrease (increase) in accounts receivable	(60,062)	(2,248)
Decrease (increase) in receivable from affiliates	(4,305)	(1,353)
Decrease (increase) in inventories	(15,918)	(36,065)
Decrease (increase) in derivatives and margin deposits	(2,163)	(287)
Decrease (increase) in other current assets	956	(3,134)
Decrease (increase) in other assets	(1,266)	(2,096)
Increase (decrease) in accounts payable and accrued liabilities	60,867	18,730
Increase (decrease) in payable to affiliates	3,997	5,580
Increase (decrease) in payables to pre-petition creditors	0	(3,836)
Increase (decrease) in other noncurrent liabilities	(1,453)	47
Total changes in operating assets and liabilities	$ (19,346)	$ (17,896)