Foreign Currency Sale Contracts (Detail) - Foreign Exchange Contract	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2016 EUR (€)	Dec. 31, 2016 CAD	Dec. 31, 2016 NZD
Euros
Derivative [Line Items]
Total transaction amount	$ 118,000,000		€ 100,000,000
Change in fair value gain (loss)	$ 5,000,000	$ 13,000,000
Euros | Minimum
Derivative [Line Items]
Transaction Date Range	2014-05
Forward purchase date range	2017-05
Euros | Maximum
Derivative [Line Items]
Transaction Date Range	2016-01
Forward purchase date range	2018-01
Canadian Dollars
Derivative [Line Items]
Transaction Date Range	2016-11
Total transaction amount	$ 19,000,000			CAD 25,000,000
Forward purchase date range	2018-11
Change in fair value gain (loss)		$ 3,000,000
New Zealand Dollars
Derivative [Line Items]
Transaction Date Range	2016-11
Total transaction amount	$ 32,000,000				NZD 45,000,000
Forward purchase date range	2017-02
Change in fair value gain (loss)	$ 1,000,000