Term Deposits with Various Banks Outstanding (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Term deposits outstanding	$ 309,830	$ 413,700
Short term investments
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Term deposits outstanding	309,600	413,600
Non current assets
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Term deposits outstanding	$ 230	$ 100