Fair Value of Pension Plan Assets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,666		$ 1,691
Equity Securities [Member] | US All Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	76	[1]	90	[1]
Equity Securities [Member] | US Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	76		72
Equity Securities [Member] | US Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22
Equity Securities [Member] | EAFE Composite [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	139		155
Equity Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	78		76
Fixed Income Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	69		81
Fixed Income Securities [Member] | US Corporate Bonds and US Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	132	[2]	203	[2]
Fixed Income Securities [Member] | Corporate Bond Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	500		494
Fixed Income Securities [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	263		207
Fixed Income Securities [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25		11
Alternative Investment [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	87	[3]	83	[3]
Alternative Investment [Member] | Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	[4]	11	[4]
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	50		48
Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(3)	[5]	(28)	[5]
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	142		188
United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,622		1,649		1,734
Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44		42		42
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	388		393
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | US All Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	76	[1]	90	[1]
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | US Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	76		72
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | US Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | EAFE Composite [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	139		155
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	75		76
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | US Corporate Bonds and US Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[2]
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Corporate Bond Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Alternative Investment [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[3]
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Alternative Investment [Member] | Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[4]
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[5]
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 1 [Member] | Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3
Fair Value, Inputs, Level 1 [Member] | Foreign Pension Plan [Member] | Equity Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3
Fair Value, Inputs, Level 1 [Member] | Foreign Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,097		1,125
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | US Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | EAFE Composite [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	69		81
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | US Corporate Bonds and US Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	132	[2]	203	[2]
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Corporate Bond Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	500		494
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	263		207
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Alternative Investment [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[3]
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Alternative Investment [Member] | Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[4]
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(3)	[5]	(34)	[5]
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Other securities [Member] | Interest Rate Contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	(3)	[3]	(34)	[3]
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	136		174
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	31		31
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Equity Securities [Member] | US Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Equity Securities [Member] | EAFE Composite [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Equity Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | US Corporate Bonds and US Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[2]
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | Corporate Bond Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	25		11
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Alternative Investment [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[3]
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Alternative Investment [Member] | Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[4]
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		[5]	6	[5]
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6		14
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	137		131
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | US Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | EAFE Composite [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | US Corporate Bonds and US Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[2]
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Corporate Bond Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Alternative Investment [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	87	[3]	83	[3]
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Alternative Investment [Member] | Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[4]
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	50		48
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[5]
Fair Value, Inputs, Level 3 [Member] | United States Pension Plan of US Entity [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10		11
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Equity Securities [Member] | US Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Equity Securities [Member] | EAFE Composite [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Equity Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | US Corporate Bonds and US Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[2]
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | Corporate Bond Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Alternative Investment [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[3]
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Alternative Investment [Member] | Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	[4]	11	[4]
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[5]
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets

[1] This category comprises a combination of small-, mid- and large-cap equity stocks that are allocated at the investment manager's discretion. Investments include common and preferred securities as well as equity funds that invest in these instruments.

[2] This category represents a combination of investment grade corporate bonds, sovereign bonds, Yankee bonds, asset backed securities and U.S. government bonds. Investments include fixed income funds that invest in these instruments.

[3] This category includes fund managers that invest in a well-diversified group of hedge funds where strategies include, but are not limited to, event driven, relative value, long/short market neutral, multistrategy and global macro. Investments may be made directly or through pooled funds.

[4] This category comprises contracts placed with insurance companies where the underlying assets are invested in fixed interest securities.

[5] Other assets in the U.S. represent interest rate derivatives which had a market value of $(3) at December 31, 2014 and $(34) at December 31, 2013.