XML 31 R71.htm IDEA: XBRL DOCUMENT v2.4.0.6
Postretirement Benefits (Narrative) (Details) (USD $)
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]        
Office space $ 200,000 $ 200,000    
Increase in per capita health care cost rate   7.80%    
Health care claims annual rate after 2024   4.50%    
Accumulated postretirement benefit obligation discount rate   4.50% 6.10%  
Net periodic benefit cost discount rate   5.25% 6.10% 6.29%
Number of former officers of summit   2    
Defined benefit plan effect of 1% increase (decrease) on service and interest cost components   0    
Increase or decrease accumulated postretirement benefit obligation   100,000    
Maximum [Member]
        
Defined Benefit Plan Disclosure [Line Items]        
Contribution to medical benefit   1,260    
Minimum [Member]
        
Defined Benefit Plan Disclosure [Line Items]        
Contribution to medical benefit   $ 540    
Net Periodic Postretirement Benefit Costs [Member]
        
Defined Benefit Plan Disclosure [Line Items]        
Increase or decrease in health care cost trend rates   1.00%    
Accumulated Postretirement Benefit Obligation [Member]
        
Defined Benefit Plan Disclosure [Line Items]        
Increase or decrease in health care cost trend rates   1.00%