Consolidating Guarantor Financial Information (Schedule of Consolidating Statement of Cash Flows) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 636	$ 553
Investing Activities
Capital expenditures on property, plant and equipment	(128)	(117)
Acquisitions, net of cash acquired	0	(3)
Proceeds from sale of businesses and assets, net	2	0
Capital expenditures related to Fairway Methanol LLC	0	(210)
Return of capital from subsidiary	0	0
Contributions to subsidiary	0	0
Intercompany loan receipts (disbursements)	0	0
Other, net	(12)	(24)
Net cash provided by (used in) investing activities	(138)	(354)
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	(353)	(2)
Proceeds from short-term borrowings	22	26
Repayments of short-term borrowings	(63)	(39)
Proceeds from long-term debt	170	0
Repayments of long-term debt	(183)	(12)
Purchases of treasury stock, including related fees	(200)	0
Dividends to parent	0	0
Contributions from parent	0	0
Stock option exercises	3	2
Series A common stock dividends	(98)	(84)
Return of capital to parent	0	0
(Distributions to) contributions from noncontrolling interests	(6)	155
Other, net	(24)	(11)
Net cash provided by (used in) financing activities	(732)	35
Exchange rate effects on cash and cash equivalents	2	(26)
Net increase (decrease) in cash and cash equivalents	(232)	208
Cash and cash equivalents as of beginning of period	967	780
Cash and cash equivalents as of end of period	735	988
Parent Guarantor [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	297	83
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	(200)	0
Dividends to parent	0	0
Contributions from parent	0	0
Stock option exercises	3	2
Series A common stock dividends	(98)	(84)
Return of capital to parent	0	0
(Distributions to) contributions from noncontrolling interests	0	0
Other, net	0	0
Net cash provided by (used in) financing activities	(295)	(82)
Exchange rate effects on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	2	1
Cash and cash equivalents as of beginning of period	0	0
Cash and cash equivalents as of end of period	2	1
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	294	45
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	136	0
Contributions to subsidiary	0	0
Intercompany loan receipts (disbursements)	138	3
Other, net	0	0
Net cash provided by (used in) investing activities	274	3
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	(345)	25
Proceeds from short-term borrowings	0	0
Repayments of short-term borrowings	0	0
Proceeds from long-term debt	250	15
Repayments of long-term debt	(175)	(5)
Purchases of treasury stock, including related fees	0	0
Dividends to parent	(296)	(83)
Contributions from parent	0	0
Stock option exercises	0	0
Series A common stock dividends	0	0
Return of capital to parent	0	0
(Distributions to) contributions from noncontrolling interests	0	0
Other, net	(2)	0
Net cash provided by (used in) financing activities	(568)	(48)
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	152	285
Investing Activities
Capital expenditures on property, plant and equipment	(66)	(74)
Acquisitions, net of cash acquired	0	(3)
Proceeds from sale of businesses and assets, net	1	0
Capital expenditures related to Fairway Methanol LLC	0	(9)
Return of capital from subsidiary	741	0
Contributions to subsidiary	0	(60)
Intercompany loan receipts (disbursements)	(5)	(25)
Other, net	(9)	(12)
Net cash provided by (used in) investing activities	662	(183)
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	(3)	(1)
Proceeds from short-term borrowings	0	0
Repayments of short-term borrowings	0	0
Proceeds from long-term debt	325	0
Repayments of long-term debt	(634)	(3)
Purchases of treasury stock, including related fees	0	0
Dividends to parent	(260)	(83)
Contributions from parent	0	0
Stock option exercises	0	0
Series A common stock dividends	0	0
Return of capital to parent	0	0
(Distributions to) contributions from noncontrolling interests	0	0
Other, net	(20)	(10)
Net cash provided by (used in) financing activities	(592)	(97)
Exchange rate effects on cash and cash equivalents	0	0
Net increase (decrease) in cash and cash equivalents	222	5
Cash and cash equivalents as of beginning of period	21	110
Cash and cash equivalents as of end of period	243	115
Non-Guarantors [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	449	306
Investing Activities
Capital expenditures on property, plant and equipment	(62)	(43)
Acquisitions, net of cash acquired	0	0
Proceeds from sale of businesses and assets, net	1	0
Capital expenditures related to Fairway Methanol LLC	0	(201)
Return of capital from subsidiary	0	0
Contributions to subsidiary	0	0
Intercompany loan receipts (disbursements)	90	(15)
Other, net	(3)	(12)
Net cash provided by (used in) investing activities	26	(271)
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	0	(1)
Proceeds from short-term borrowings	22	26
Repayments of short-term borrowings	(63)	(39)
Proceeds from long-term debt	0	0
Repayments of long-term debt	(7)	(7)
Purchases of treasury stock, including related fees	0	0
Dividends to parent	0	0
Contributions from parent	0	60
Stock option exercises	0	0
Series A common stock dividends	0	0
Return of capital to parent	(877)	0
(Distributions to) contributions from noncontrolling interests	(6)	155
Other, net	(2)	(1)
Net cash provided by (used in) financing activities	(933)	193
Exchange rate effects on cash and cash equivalents	2	(26)
Net increase (decrease) in cash and cash equivalents	(456)	202
Cash and cash equivalents as of beginning of period	946	670
Cash and cash equivalents as of end of period	490	872
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(556)	(166)
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	(877)	0
Contributions to subsidiary	0	60
Intercompany loan receipts (disbursements)	(223)	37
Other, net	0	0
Net cash provided by (used in) investing activities	(1,100)	97
Financing Activities
Net change in short-term borrowings with maturities of 3 months or less	(5)	(25)
Proceeds from short-term borrowings	0	0
Repayments of short-term borrowings	0	0
Proceeds from long-term debt	(405)	(15)
Repayments of long-term debt	633	3
Purchases of treasury stock, including related fees	0	0
Dividends to parent	556	166
Contributions from parent	0	(60)
Stock option exercises	0	0
Series A common stock dividends	0	0
Return of capital to parent	877	0
(Distributions to) contributions from noncontrolling interests	0	0
Other, net	0	0
Net cash provided by (used in) financing activities	1,656	69
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