Ventures and Variable Interest Entities (Schedule of Variable Interest Entities) (Details) - USD ($) $ in Millions		Mar. 31, 2016	Dec. 31, 2015		Mar. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Cash and cash equivalents		$ 716	$ 967		$ 851	$ 780
Trade receivables - third party and affiliates		830	706
Property, plant and equipment (net of accumulated depreciation - 2016: $20; 2015: $10)		3,640	3,609
Accumulated depreciation		2,132	2,039
Intangible assets (net of accumulated amortization - 2016: $0; 2015: $0)		125	125
Finite-Lived Intangible Assets, Accumulated Amortization		546	528
Other assets		296	300
Total assets		8,392	8,586
Trade payables		574	587
Current liabilities		1,095	1,550
Deferred income taxes		116	136
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents			7
Trade receivables - third party and affiliates		5	6
Property, plant and equipment (net of accumulated depreciation - 2016: $20; 2015: $10)			772
Intangible assets (net of accumulated amortization - 2016: $0; 2015: $0)		27	27
Other assets			13
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Property, plant and equipment (net of accumulated depreciation - 2016: $20; 2015: $10)		70	73
Trade payables		52	47
Current installments of long-term debt		10	10
Long-term debt		106	109
Total liabilities		168	166
Maximum exposure to loss		267	268
Fairway Methanol LLC [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents		18	7
Trade receivables - third party and affiliates		10	12
Property, plant and equipment (net of accumulated depreciation - 2016: $20; 2015: $10)		763	772
Accumulated depreciation		20	10
Intangible assets (net of accumulated amortization - 2016: $0; 2015: $0)		27	27
Finite-Lived Intangible Assets, Accumulated Amortization		0	0
Other assets		10	13
Total assets		828	831	[1]
Trade payables		7	9
Current liabilities	[2]	3	5
Long-term debt		5	5
Deferred income taxes		2	2
Total liabilities		$ 17	$ 21

[1] Assets can only be used to settle the obligations of Fairway.

[2] Primarily represents amounts owed by Fairway to the Company for reimbursement of expenditures.