Segment Reporting Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Cost of goods sold	$ 2,510	$ 2,068	$ 4,601	$ 4,120
Net sales	2,919	2,332	5,356	4,704
Automotive Segment
Disaggregation of Revenue [Line Items]
Cost of goods sold	384	372	746	729
Net sales	602	569	1,160	1,098
Revenue from contracts with customers	737	694	1,423	1,331
Energy Segment
Disaggregation of Revenue [Line Items]
Cost of goods sold	1,776	1,416	3,206	2,834
Net sales	1,914	1,434	3,451	2,942
Revenue from contracts with customers	1,914	1,434	3,451	2,942
Automotive services \| Automotive Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	334	294	651	561
Commercial sales \| Automotive Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	264	259	500	497
Retail sales \| Automotive Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	139	141	272	273
Petroleum products \| Energy Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,821	1,336	3,278	2,759
Nitrogen fertilizer products \| Energy Segment
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	93	98	173	183
Difference between Revenue Guidance in Effect before and after adoption \| Automotive Segment
Disaggregation of Revenue [Line Items]
Cost of goods sold	16	18	32	36
Net sales	$ 16	$ 18	$ 32	$ 36

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
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130545-203045

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+ References

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 210.5-03.1(a))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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