Ventures and Variable Interest Entities (Schedule of Variable Interest Entities) (Details) - USD ($) $ in Millions		Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Cash and cash equivalents		$ 735	$ 967	$ 988	$ 780
Trade receivables - third party and affiliates		792	706
Property, plant and equipment (net of accumulated depreciation - 2016: $30; 2015: $10)		3,588	3,609
Accumulated depreciation		2,164	2,039
Intangible assets (net of accumulated amortization - 2016: $1; 2015: $0)		121	125
Finite-Lived Intangible Assets, Accumulated Amortization		538	528
Other assets		293	300
Total assets		8,248	8,586
Trade payables		551	587
Current liabilities		1,087	1,550
Deferred income taxes			136
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents		23	7
Trade receivables - third party and affiliates		5	6
Property, plant and equipment (net of accumulated depreciation - 2016: $30; 2015: $10)		754	772
Intangible assets (net of accumulated amortization - 2016: $1; 2015: $0)		26	27
Other assets		10	13
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Property, plant and equipment (net of accumulated depreciation - 2016: $30; 2015: $10)		67	73
Trade payables		49	47
Current installments of long-term debt		10	10
Long-term debt		100	109
Total liabilities		159	166
Maximum exposure to loss		254	268
Fairway Methanol LLC [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents		23	7
Trade receivables - third party and affiliates		10	12
Property, plant and equipment (net of accumulated depreciation - 2016: $30; 2015: $10)		754	772
Accumulated depreciation		30	10
Intangible assets (net of accumulated amortization - 2016: $1; 2015: $0)		26	27
Finite-Lived Intangible Assets, Accumulated Amortization		1	0
Other assets		10	13
Total assets	[1]	823	831
Trade payables		11	9
Current liabilities	[2]	3	5
Long-term debt		5	5
Deferred income taxes		2	2
Total liabilities		$ 21	$ 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.