Revenue - Revenue Disaggregated by Major Product (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Net sales	$ 1,783	$ 675	$ 3,246	$ 1,806
Revenue from product sales
Disaggregation of Revenue [Line Items]
Revenue from product sales	1,774	665	3,208	1,757
Gasoline
Disaggregation of Revenue [Line Items]
Revenue from product sales	908	300	1,657	816
Distillates
Disaggregation of Revenue [Line Items]
Revenue from product sales	685	246	1,273	720
Ammonia
Disaggregation of Revenue [Line Items]
Revenue from product sales	32	37	42	51
UAN
Disaggregation of Revenue [Line Items]
Revenue from product sales	87	55	126	102
Other urea products
Disaggregation of Revenue [Line Items]
Revenue from product sales	7	4	11	7
Freight revenue
Disaggregation of Revenue [Line Items]
Revenue from product sales	14	11	26	24
Other
Disaggregation of Revenue [Line Items]
Revenue from product sales	41	12	73	37
Crude oil sales
Disaggregation of Revenue [Line Items]
Revenue from product sales	8	10	37	48
Other revenue
Disaggregation of Revenue [Line Items]
Other revenue	1	0	1	1
Operating Segments \| Petroleum
Disaggregation of Revenue [Line Items]
Net sales	1,648	572	3,052	1,629
Operating Segments \| Petroleum \| Revenue from product sales
Disaggregation of Revenue [Line Items]
Revenue from product sales	1,639	562	3,014	1,580
Operating Segments \| Petroleum \| Gasoline
Disaggregation of Revenue [Line Items]
Revenue from product sales	908	300	1,657	816
Operating Segments \| Petroleum \| Distillates
Disaggregation of Revenue [Line Items]
Revenue from product sales	685	246	1,273	720
Operating Segments \| Petroleum \| Ammonia
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Operating Segments \| Petroleum \| UAN
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Operating Segments \| Petroleum \| Other urea products
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Operating Segments \| Petroleum \| Freight revenue
Disaggregation of Revenue [Line Items]
Revenue from product sales	5	4	11	9
Operating Segments \| Petroleum \| Other
Disaggregation of Revenue [Line Items]
Revenue from product sales	41	12	73	35
Operating Segments \| Petroleum \| Crude oil sales
Disaggregation of Revenue [Line Items]
Revenue from product sales	8	10	37	48
Operating Segments \| Petroleum \| Other revenue
Disaggregation of Revenue [Line Items]
Other revenue	1	0	1	1
Operating Segments \| Nitrogen Fertilizer
Disaggregation of Revenue [Line Items]
Net sales	138	105	199	180
Operating Segments \| Nitrogen Fertilizer \| Revenue from product sales
Disaggregation of Revenue [Line Items]
Revenue from product sales	138	105	199	180
Operating Segments \| Nitrogen Fertilizer \| Gasoline
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Operating Segments \| Nitrogen Fertilizer \| Distillates
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Operating Segments \| Nitrogen Fertilizer \| Ammonia
Disaggregation of Revenue [Line Items]
Revenue from product sales	32	37	42	51
Operating Segments \| Nitrogen Fertilizer \| UAN
Disaggregation of Revenue [Line Items]
Revenue from product sales	87	55	126	102
Operating Segments \| Nitrogen Fertilizer \| Other urea products
Disaggregation of Revenue [Line Items]
Revenue from product sales	7	4	11	7
Operating Segments \| Nitrogen Fertilizer \| Freight revenue
Disaggregation of Revenue [Line Items]
Revenue from product sales	9	7	15	15
Operating Segments \| Nitrogen Fertilizer \| Other
Disaggregation of Revenue [Line Items]
Revenue from product sales	3	2	5	5
Operating Segments \| Nitrogen Fertilizer \| Crude oil sales
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Operating Segments \| Nitrogen Fertilizer \| Other revenue
Disaggregation of Revenue [Line Items]
Other revenue	0	0	0	0
Other / Elimination
Disaggregation of Revenue [Line Items]
Net sales	(3)	(2)	(5)	(3)
Other / Elimination \| Revenue from product sales
Disaggregation of Revenue [Line Items]
Revenue from product sales	(3)	(2)	(5)	(3)
Other / Elimination \| Gasoline
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Other / Elimination \| Distillates
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Other / Elimination \| Ammonia
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Other / Elimination \| UAN
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Other / Elimination \| Other urea products
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Other / Elimination \| Freight revenue
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Other / Elimination \| Other
Disaggregation of Revenue [Line Items]
Revenue from product sales	(3)	(2)	(5)	(3)
Other / Elimination \| Crude oil sales
Disaggregation of Revenue [Line Items]
Revenue from product sales	0	0	0	0
Other / Elimination \| Other revenue
Disaggregation of Revenue [Line Items]
Other revenue	$ 0	$ 0	$ 0	$ 0