Investment Assets (Excluding Equity and Cost Method Investments) and Derivatives Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Derivative Financial Instruments, Liabilities | Interest rate derivatives
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of liabilities, recurring basis	$ (7,991)	$ (9,006)
Derivative Financial Instruments, Liabilities | Foreign currency contracts
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of liabilities, recurring basis	(9,292)	(3,671)
Derivative Financial Instruments, Assets | Interest rate derivatives
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	7,906	7,860
Derivative Financial Instruments, Assets | Foreign currency contracts
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	273	7,369
Certificates of deposit (foreign)
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	12,644	87,372
Corporate bonds
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	26,112	34,133
Short-term bond fund
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis		5,046
Corporate obligations
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	4	3
Money markets
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	54	54
Mutual funds
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	111	101
Other Investments
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	5,138	4,235
Level 1 | Short-term bond fund
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis		5,046
Level 1 | Money markets
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	54	54
Level 1 | Mutual funds
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	111	101
Level 2 | Derivative Financial Instruments, Liabilities | Interest rate derivatives
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of liabilities, recurring basis	(7,991)	(9,006)
Level 2 | Derivative Financial Instruments, Liabilities | Foreign currency contracts
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of liabilities, recurring basis	(9,292)	(3,671)
Level 2 | Derivative Financial Instruments, Assets | Interest rate derivatives
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	7,906	7,860
Level 2 | Derivative Financial Instruments, Assets | Foreign currency contracts
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	273	7,369
Level 2 | Certificates of deposit (foreign)
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	12,644	87,372
Level 2 | Corporate bonds
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	26,112	34,133
Level 2 | Corporate obligations
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	4	3
Level 2 | Other Investments
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]
Fair value of assets, recurring basis	$ 5,138	$ 4,235