Supplemental Cash Flow Information - Operating assets and liabilities (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Components of operating assets and liabilities
Decrease (increase) in restricted cash	$ 32	$ 6,798
Decrease (increase) in accounts receivable	(4,245)	8,179
Decrease (increase) in receivable from affiliates	1,372	8,986
Decrease (increase) in inventories	(14,397)	(23,256)
Decrease (increase) in derivatives and margin deposits	(6,011)	3,159
Decrease (increase) in other current assets	2,402	(1,807)
Decrease (increase) in other assets	63	1,818
Increase (decrease) in accounts payable and accrued liabilities	22,138	1,259
Increase (decrease) in payable to affiliates	758	(2,310)
Increase (decrease) in payables to pre-petition creditors	0	(3,836)
Increase (decrease) in other noncurrent liabilities	(1,311)	(1,336)
Total changes in operating assets and liabilities	$ 801	$ (2,346)