Pensions and Other Postretirement Benefits (Changes in Projected Benefit Obligations, Plan Assets and Funded Status) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefits paid		$ (22)	$ (70)
Curtailment and special termination benefits	(33)
Amounts recognized in the Consolidated Balance Sheet:
Accounts payable and accrued liabilities		(93)	(103)
Accrued pensions		(728)	(1,057)
Other postretirement benefits		(1,007)	(1,287)
Pensions
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation, Beginning of year	5,784	5,784	5,333
Service cost		57	54
Interest cost		218	217
Plan amendments		(25)	(2)
Actuarial losses / (gains) - net		(267)	443
Benefits paid		(304)	(347)
Defined Benefit Plan, Other Changes		327
Foreign currency translation adjustments		12	59
Curtailment and special termination benefits		(18)	(6)
Defined Benefit Plan, Change in Benefit Obligation Attributable to Commodity Chemicals Business		(548)	29
Other		4	4
Projected benefit obligation, End of year		5,240	5,784
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning Balance	4,750	4,750	4,382
Actual return on plan assets		267	571
Company contributions		174	80
Participant contributions		2	2
Benefits paid		(283)	(335)
Defined Benefit Plan, Assets Transferred to (from) Plan		(352)
Defined Benefit Plan, Settlements, Plan Assets		(51)
Plan expenses and other-net		(2)	(1)
Foreign currency translation adjustments		(11)	50
Defined Benefit Plan, Change in Plan Assets Attributable to Commodity Chemicals Business		(496)	1
Plan Assets, Other Change		(1)
Ending Balance		4,701	4,750
Funded Status		(539)	(1,034)
Amounts recognized in the Consolidated Balance Sheet:
Other assets (long-term)		224	27
Accounts payable and accrued liabilities		(19)	(20)
Accrued pensions		(744)	(1,041)
Other postretirement benefits		0	0
Net liability recognized		(539)	(1,034)
Other Postretirement Benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation, Beginning of year	1,362	1,362	1,394
Service cost		20	19
Interest cost		49	50
Plan amendments		(8)	(19)
Actuarial losses / (gains) - net		(160)	(33)
Benefits paid		(60)	(62)
Defined Benefit Plan, Other Changes		40
Foreign currency translation adjustments		(8)	3
Curtailment and special termination benefits		0	0
Defined Benefit Plan, Change in Benefit Obligation Attributable to Commodity Chemicals Business		(165)	10
Other		0	0
Projected benefit obligation, End of year		1,070	1,362
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Funded Status		(1,070)	(1,362)
Amounts recognized in the Consolidated Balance Sheet:
Other assets (long-term)		0	0
Accounts payable and accrued liabilities		(63)	(75)
Accrued pensions		0	0
Other postretirement benefits		(1,007)	(1,287)
Net liability recognized		$ (1,070)	$ (1,362)