Fair Value of Outstanding Debt (Detail) $ in Thousands, € in Millions	Jun. 30, 2016 USD ($)	Jun. 30, 2016 EUR (€)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 EUR (€)
7.456% Senior Notes Due 2018
Debt Instrument [Line Items]
Fair value of senior notes	$ 556,000		$ 555,000
5.95% Senior Notes Due 2020
Debt Instrument [Line Items]
Fair value of senior notes	841,000		827,000
2.5% Senior Notes Due 2022
Debt Instrument [Line Items]
Fair value of senior notes	746,000	€ 673	705,000	€ 644
4.5% Senior Notes Due 2024
Debt Instrument [Line Items]
Fair value of senior notes	528,000		487,000
5.0% Senior Notes Due 2026
Debt Instrument [Line Items]
Fair value of senior notes	$ 778,000		$ 750,000