Employee Benefit Plans (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, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefits paid		$ (61)	$ (22)
Curtailment and special termination benefits	(33)
Amounts recognized in the Consolidated Balance Sheet:
Accounts payable and accrued liabilities		(94)	(93)
Accrued pensions		(995)	(728)
Other postretirement benefits		(1,132)	(1,007)
Pensions
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation, Beginning of year	5,784	5,240	5,784
Service cost		52	57
Interest cost		230	218
Plan amendments		0	(25)
Actuarial losses / (gains) - net		846	(267)
Benefits paid		(390)	(304)
Plan transfers		36	327
Foreign currency translation adjustments		(229)	12
Curtailment and special termination benefits		(6)	(18)
Impact of commodity chemicals transaction		0	(548)
Other		(4)	4
Projected benefit obligation, End of year		5,775	5,240
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	4,750	4,701	4,750
Actual return on plan assets		658	267
Company contributions		41	174
Participant contributions		2	2
Benefits paid		(375)	(283)
Plan transfers		35	352
Plan settlements		(4)	(51)
Plan expenses and other-net		4	2
Foreign currency translation adjustments		(198)	(11)
Impact of commodity chemicals transaction		(22)	(496)
Other		5	(1)
End balance		4,839	4,701
Funded Status		(936)	(539)
Amounts recognized in the Consolidated Balance Sheet:
Other assets (long-term)		86	224
Accounts payable and accrued liabilities		(27)	(19)
Accrued pensions		(995)	(744)
Other postretirement benefits		0	0
Net liability recognized		(936)	(539)
Other Postretirement Benefits
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation, Beginning of year	1,362	1,070	1,362
Service cost		15	20
Interest cost		47	49
Plan amendments		0	(8)
Actuarial losses / (gains) - net		125	(160)
Benefits paid		(44)	(60)
Plan transfers		0	40
Foreign currency translation adjustments		(12)	(8)
Curtailment and special termination benefits		0	0
Impact of commodity chemicals transaction		0	(165)
Other		(5)	0
Projected benefit obligation, End of year		1,196	1,070
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Funded Status		(1,196)	(1,070)
Amounts recognized in the Consolidated Balance Sheet:
Other assets (long-term)		0	0
Accounts payable and accrued liabilities		(64)	(63)
Accrued pensions		0	0
Other postretirement benefits		(1,132)	(1,007)
Net liability recognized		$ (1,196)	$ (1,070)