Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2018

Long-term Purchase Commitment [Line Items]

Summary Of Purchase And Sale Commitments

We account for derivatives at fair value with the exception of commitments that have been designated as normal purchases and sales for which we do not record assets or liabilities related to these agreements until the product is purchased or sold. At March 31, 2018, such commitments included the following (in thousands):

	Volume (Barrels)	Value
Fixed price purchases	1,360	$	85,555
Fixed price sales	1,590	$	99,470
Floating price purchases	8,366	$	531,648
Floating price sales	10,884	$	567,025

Long-term Purchase Commitment [Table Text Block]

The approximate amount of future obligation is as follows (in thousands):

For year ending:
December 31, 2018	$	7,950
December 31, 2019	9,567
December 31, 2020	8,864
December 31, 2021	7,175
December 31, 2022	6,753
Thereafter	2,791
Total expected future payments	$	43,100

Recorded Unconditional Purchase Obligations [Table Text Block]

The approximate amount of future obligations is as follows (in thousands):

For year ending:
December 31, 2018	$	16,214
December 31, 2019	21,865
December 31, 2020	19,770
December 31, 2021	12,976
December 31, 2022	13,231
Thereafter	20,312
Total expected future payments	$	104,368