Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Income tax associated with reclassification adjustment $ 3,800,000 $ 2,000,000 $ 1,800,000
Supplemental Director Retirement Plan [Member]
     
Provision for income tax associated with the reclassification adjustments on salaries and employee benefits 31,000 28,000 10,000
Long-Term Health Care Plan [Member]
     
Provision for income tax associated with the reclassification adjustments on salaries and employee benefits $ 8,000 $ 12,000 $ 6,000