Financial Instruments - Summarization for Foreign Currency Forward Purchase and Sale Contracts (Detail) - Dec. 31, 2015 - Foreign Exchange Forward ¥ in Millions, $ in Millions	USD ($)	JPY (¥)
Long [Member] | Australia, Dollars
Derivative, Notional Amount	$ (1)
Long [Member] | United Kingdom, Pounds
Derivative, Notional Amount	(45)
Long [Member] | South Africa, Rand
Derivative, Notional Amount	(80)
Long [Member] | United States of America, Dollars
Derivative, Notional Amount	(93)
Short [Member] | United Kingdom, Pounds
Derivative, Notional Amount	(43)
Short [Member] | Canada, Dollars
Derivative, Notional Amount	(2)
Short [Member] | Euro Member Countries, Euro
Derivative, Notional Amount	(16)
Short [Member] | Japan, Yen
Derivative, Notional Amount	(50)	¥ (1,153)
Short [Member] | United States of America, Dollars
Derivative, Notional Amount	$ (71)