v3.3.1.900
Fair Value Measurements and Disclosures (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Fair value adjustment of marketable securities and deferred compensation plan liability      
Net gain on marketable securities $ (269) $ 397 $ 1,489
Fair Value (Level 1) [Member]      
Assets and Liabilities Reported at Fair Value      
Marketable securities [1],[2] $ 12,882 $ 11,971  
[1] Fair value calculated using Level 1 inputs based on quoted prices in active markets for identical securities.
[2] The marketable securities are held in a limited rabbi trust.