Fair Value Accounting - Schedule of Measure at Fair Value on Recurring Basis (Detail) - Measured at Fair Value on Recurring Basis - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure
Short-term investments	$ 21,849	$ 75,143
Interest rate derivatives	0	5
Net asset	21,849	75,148
Level 1
Defined Benefit Plan Disclosure
Short-term investments	1	666
Interest rate derivatives	0	0
Net asset	1	666
Level 2
Defined Benefit Plan Disclosure
Short-term investments	21,848	74,477
Interest rate derivatives	0	5
Net asset	$ 21,848	$ 74,482