Annual report pursuant to Section 13 and 15(d)

Deferred Compensation (Narrative) (Details)

v3.8.0.1
Deferred Compensation (Narrative) (Details) - Former Officers [Member] - USD ($)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]    
Minimum period of deferred compensation benefits (years) 10 years  
Minimum deferred compensation benefit age (years) 65 years  
Estimate of Fair Value, Fair Value Disclosure [Member]    
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]    
Present value of vested future deferred compensation payments $ 159,080 $ 171,015