Taxes On Income (Reconciliation from the Expected Tax Expense (Benefit) Using the U.S. Federal Income Tax Rate) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Taxes On Income [Abstract]      
Computed tax (benefit) expense at statutory rates $ 11,777 $ 9,867 $ 9,124
Increase (decrease) in income taxes results from:      
Benefit of income not subject to U.S. Federal income tax (209) (213) (213)
Expenses not deductible for U.S. Federal income tax 129 96 150
State income taxes, net of Federal income tax benefit 907 749 476
Texas tax refund (federally tax affected)     50
Other 13 181 296
Income Tax Expense (Benefit), Total 12,617 10,756 9,883
Tax Credit Recapture   $ 76