Income Taxes (Income Tax Expense Differed From Statutory Federal Income Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Statutory federal tax rate	35.00%	35.00%	35.00%
Tax exempt interest income	(6.10%)	(5.10%)	(4.80%)
Tax credits and adjustments	(0.70%)	(3.50%)
Non-taxable earnings on company owned life insurance	(1.80%)	(1.60%)	(1.60%)
State taxes, net of federal tax benefit	0.70%	(0.80%)	3.80%
Nondeductible expenses	0.30%	0.50%	0.20%
Goodwill and contingent consideration adjustments	(0.30%)
Other, net		0.20%	0.10%
Effective tax rate	27.10%	24.70%	32.70%