Segment Reporting Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Cost of goods sold	$ 2,406	$ 2,054	$ 7,007	$ 6,174
Net sales	2,864	2,404	8,220	7,107
Automotive Segment
Disaggregation of Revenue [Line Items]
Cost of goods sold	373	396	1,119	1,125
Net sales	600	604	1,760	1,702
Revenue from contracts with customers	735	700	2,158	2,031
Energy Segment
Disaggregation of Revenue [Line Items]
Cost of goods sold	1,742	1,357	4,948	4,191
Net sales	1,935	1,454	5,386	4,395
Revenue from contracts with customers	1,935	1,454	5,386	4,395
Automotive services \| Automotive Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	341	311	992	873
Commercial sales \| Automotive Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	258	246	758	740
Retail sales \| Automotive Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	136	143	408	418
Petroleum products \| Energy Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,855	1,384	5,133	4,142
Nitrogen fertilizer products \| Energy Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	80	70	253	253
Difference between Revenue Guidance in Effect before and after adoption \| Automotive Segment
Disaggregation of Revenue [Line Items]
Cost of goods sold	15	14	47	50
Net sales	$ 15	$ 14	$ 47	$ 50

Total costs related to goods produced and sold during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 32
-Paragraph 2A
-URI http://asc.fasb.org/extlink&oid=82859839&loc=SL82860478-203043

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130543-203045

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130539-203045

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130545-203045

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
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-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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