Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Retirement Plans and Employee Rights Upon Termination (Narrative) (Details)

v3.7.0.1
Retirement Plans and Employee Rights Upon Termination (Narrative) (Details) - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]      
Severance liabilities $ 3,700,000 $ 3,800,000  
Employee contribution percentage 4.00%    
Employer contributions matching amount $ 3,000    
Percent of employee contribution matched by the Company 50.00%    
Employer contribution amount $ 3,800,000 4,200,000 $ 2,800,000
Future benefits to employees $ 2,700,000 $ 2,700,000