XML 34 R23.htm IDEA: XBRL DOCUMENT v3.5.0.2
NET INCOME PER COMMON SHARE AND EQUITY PER COMMON SHARE (Details) - $ / shares
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Shares used in computing basic and diluted net income per share [Abstract]          
Weighted average common shares outstanding during the period for Basic computation (in shares) 9,112,000 8,960,000 9,090,000 8,935,000  
Dilutive effect of employee stock options (in shares) 65,000 40,000 64,000 37,000  
Weighted average common shares outstanding during the period for Diluted computation (in shares) 9,177,000 9,000,000 9,154,000 8,972,000  
Common stock excluded from calculations of diluted net income per share (in shares)     3,780    
Class A Stock [Member]          
Class of Stock [Line Items]          
Common stock, shares authorized (in shares) 15,000,000   15,000,000    
Common stock, shares issued (in shares) 8,232,645 8,119,781 8,232,645 8,119,781  
Common stock, shares outstanding (in shares) 8,232,645 8,119,781 8,232,645 8,119,781  
Common stock, par value (in dollars per share) $ 1.00   $ 1.00    
Common stock, shares issued during period (in shares) 7,352 72,200 56,432 89,104  
Equity per common share (in dollars per share)     $ 14.95   $ 14.77
Class B Stock [Member]          
Class of Stock [Line Items]          
Common stock, shares authorized (in shares) 1,040,000   1,040,000    
Common stock, shares issued (in shares) 881,452 881,452 881,452 881,452  
Common stock, shares outstanding (in shares) 881,452 881,452 881,452 881,452  
Common stock, par value (in dollars per share) $ 1.00   $ 1.00