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Profit Sharing Plan - Additional Information (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Compensation And Retirement Disclosure [Abstract]      
Employer matching contribution, percent of match 50.00%    
Employer matching contribution, percent of employees' gross pay 15.00%    
Matching contribution amounts $ 4.4 $ 4.3 $ 4.6