- Foreign Exchange Forward Contracts Fair Value on Gross Basis (Detail) (Foreign Exchange Forward, USD $) In Millions, unless otherwise specified	Dec. 31, 2014
Long [Member] | Australia, Dollars
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 3
Long [Member] | United Kingdom, Pounds
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1
Long [Member] | Euro Member Countries, Euro
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	(1)
Long [Member] | South Africa, Rand
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	112
Long [Member] | United States of America, Dollars
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	14
Short [Member] | Canada, Dollars
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	2
Short [Member] | Euro Member Countries, Euro
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4
Short [Member] | Japan, Yen
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	(1,268)
Short [Member] | United States of America, Dollars
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 10