Financial Instruments - Summarization for Foreign Currency Forward Purchase and Sale Contracts (Detail) - Dec. 31, 2016 - Foreign Exchange Forward ¥ in Millions, $ in Millions	USD ($)	JPY (¥)
Long [Member] | United Kingdom, Pounds
Derivative, Notional Amount	$ 9
Long [Member] | Euro Member Countries, Euro
Derivative, Notional Amount	21
Long [Member] | Japan, Yen
Derivative, Notional Amount	388
Long [Member] | South Africa, Rand
Derivative, Notional Amount	131
Long [Member] | United States of America, Dollars
Derivative, Notional Amount	5
Short [Member] | Canada, Dollars
Derivative, Notional Amount	2
Short [Member] | Euro Member Countries, Euro
Derivative, Notional Amount	3
Short [Member] | Japan, Yen
Derivative, Notional Amount | ¥		¥ 60
Short [Member] | South Africa, Rand
Derivative, Notional Amount | ¥		¥ 17
Short [Member] | United States of America, Dollars
Derivative, Notional Amount	$ 45