Investments - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Long-term Investments	$ 16,388	$ 14,145
U.S. Non-Qualified Deferred Compensation Plan [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Aggregate cost basis for investments	13,100	11,100
Fair Value, Inputs, Level 1 [Member] | U.S. Non-Qualified Deferred Compensation Plan [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Long-term Investments	$ 16,400	$ 14,100