Consolidating Guarantor Financial Information (Schedule of Consolidating Statement of Cash Flows) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 726	$ 796
Investing Activities
Capital expenditures on property, plant and equipment	(168)	(189)
Acquisitions, net of cash acquired	(3)	0
Proceeds from sale of businesses and assets, net	0	0
Capital expenditures related to Fairway Methanol LLC	(263)	(275)
Return of capital from subsidiary	0	0
Contributions to subsidiary	0	0
Intercompany loan receipts (disbursements)	0	0
Other, net	(27)	(13)
Net cash provided by (used in) investing activities	(461)	(477)
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	346	12
Proceeds from short-term borrowings	40	47
Repayments of short-term borrowings	(60)	(70)
Proceeds from long-term debt	0	387
Repayments of long-term debt	(18)	(19)
Purchases of treasury stock, including related fees	(420)	(201)
Dividends to parent	0	0
Contributions from parent	0	0
Stock option exercises	2	4
Series A common stock dividends	(131)	(106)
Return of capital to parent	0	0
Contributions from noncontrolling interests	187	194
Other, net	(10)	(11)
Net cash provided by (used in) financing activities	(64)	237
Exchange rate effects on cash and cash equivalents	(29)	(30)
Net increase (decrease) in cash and cash equivalents	172	526
Cash and cash equivalents as of beginning of period	780	984
Cash and cash equivalents as of end of period	952	1,510
Parent Guarantor [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	549	303
Investing Activities
Capital expenditures on property, plant and equipment	0	0
Acquisitions, net of cash acquired	0	0
Proceeds from sale of businesses and assets, net	0	0
Capital expenditures related to Fairway Methanol LLC	0	0
Return of capital from subsidiary	0	0
Contributions to subsidiary	0	0
Intercompany loan receipts (disbursements)	0	0
Other, net	0	0
Net cash provided by (used in) investing activities	0	0
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	0	0
Proceeds from short-term borrowings	0	0
Repayments of short-term borrowings	0	0
Proceeds from long-term debt	0	0
Repayments of long-term debt	0	0
Purchases of treasury stock, including related fees	(420)	(201)
Dividends to parent	0	0
Contributions from parent	0	0
Stock option exercises	2	4
Series A common stock dividends	(131)	(106)
Return of capital to parent	0	0
Contributions from noncontrolling interests	0	0
Other, net	0	0
Net cash provided by (used in) financing activities	(549)	(303)
Exchange rate effects on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents as of beginning of period	0	0
Cash and cash equivalents as of end of period	0	0
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	507	444
Investing Activities
Capital expenditures on property, plant and equipment	0	0
Acquisitions, net of cash acquired	0	0
Proceeds from sale of businesses and assets, net	0	0
Capital expenditures related to Fairway Methanol LLC	0	0
Return of capital from subsidiary	0	28
Contributions to subsidiary	0	0
Intercompany loan receipts (disbursements)	(342)	4
Other, net	0	0
Net cash provided by (used in) investing activities	(342)	32
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	374	(543)
Proceeds from short-term borrowings	0	0
Repayments of short-term borrowings	0	0
Proceeds from long-term debt	15	387
Repayments of long-term debt	(7)	(7)
Purchases of treasury stock, including related fees	0	0
Dividends to parent	(547)	(303)
Contributions from parent	0	0
Stock option exercises	0	0
Series A common stock dividends	0	0
Return of capital to parent	0	0
Contributions from noncontrolling interests	0	0
Other, net	0	(10)
Net cash provided by (used in) financing activities	(165)	(476)
Exchange rate effects on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents as of beginning of period	0	0
Cash and cash equivalents as of end of period	0	0
Subsidiary Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	406	573
Investing Activities
Capital expenditures on property, plant and equipment	(100)	(142)
Acquisitions, net of cash acquired	(3)	0
Proceeds from sale of businesses and assets, net	0	0
Capital expenditures related to Fairway Methanol LLC	(19)	(39)
Return of capital from subsidiary	0	51
Contributions to subsidiary	(92)	(143)
Intercompany loan receipts (disbursements)	(29)	543
Other, net	(12)	(8)
Net cash provided by (used in) investing activities	(255)	262
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	2	13
Proceeds from short-term borrowings	0	0
Repayments of short-term borrowings	0	0
Proceeds from long-term debt	345	0
Repayments of long-term debt	(3)	(4)
Purchases of treasury stock, including related fees	0	0
Dividends to parent	(569)	(303)
Contributions from parent	0	0
Stock option exercises	0	0
Series A common stock dividends	0	0
Return of capital to parent	0	0
Contributions from noncontrolling interests	0	0
Other, net	(9)	(1)
Net cash provided by (used in) financing activities	(234)	(295)
Exchange rate effects on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	(83)	540
Cash and cash equivalents as of beginning of period	110	284
Cash and cash equivalents as of end of period	27	824
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	380	304
Investing Activities
Capital expenditures on property, plant and equipment	(68)	(47)
Acquisitions, net of cash acquired	0	0
Proceeds from sale of businesses and assets, net	0	0
Capital expenditures related to Fairway Methanol LLC	(244)	(236)
Return of capital from subsidiary	0	0
Contributions to subsidiary	0	0
Intercompany loan receipts (disbursements)	(15)	0
Other, net	(15)	(5)
Net cash provided by (used in) investing activities	(342)	(288)
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	(1)	(1)
Proceeds from short-term borrowings	40	47
Repayments of short-term borrowings	(60)	(70)
Proceeds from long-term debt	0	0
Repayments of long-term debt	(11)	(12)
Purchases of treasury stock, including related fees	0	0
Dividends to parent	0	(222)
Contributions from parent	92	143
Stock option exercises	0	0
Series A common stock dividends	0	0
Return of capital to parent	0	(79)
Contributions from noncontrolling interests	187	194
Other, net	(1)	0
Net cash provided by (used in) financing activities	246	0
Exchange rate effects on cash and cash equivalents	(29)	(30)
Net increase (decrease) in cash and cash equivalents	255	(14)
Cash and cash equivalents as of beginning of period	670	700
Cash and cash equivalents as of end of period	925	686
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(1,116)	(828)
Investing Activities
Capital expenditures on property, plant and equipment	0	0
Acquisitions, net of cash acquired	0	0
Proceeds from sale of businesses and assets, net	0	0
Capital expenditures related to Fairway Methanol LLC	0	0
Return of capital from subsidiary	0	(79)
Contributions to subsidiary	92	143
Intercompany loan receipts (disbursements)	386	(547)
Other, net	0	0
Net cash provided by (used in) investing activities	478	(483)
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	(29)	543
Proceeds from short-term borrowings	0	0
Repayments of short-term borrowings	0	0
Proceeds from long-term debt	(360)	0
Repayments of long-term debt	3	4
Purchases of treasury stock, including related fees	0	0
Dividends to parent	1,116	828
Contributions from parent	(92)	(143)
Stock option exercises	0	0
Series A common stock dividends	0	0
Return of capital to parent	0	79
Contributions from noncontrolling interests	0	0
Other, net	0	0
Net cash provided by (used in) financing activities	638	1,311
Exchange rate effects on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents as of beginning of period	0	0
Cash and cash equivalents as of end of period	$ 0	$ 0