Parent Only Financial Information Parent Only Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
ASSETS
Interest-Bearing Deposits at Banks	$ 14,331	$ 16,252
Available-for-Sale	346,996	402,309
Held-to-Maturity (Approximate Fair Value of $343,751 at December 31, 2016, and $325,930 at December 31, 2015)	345,427	320,611
Other Assets	56,789	53,027
Total Assets	2,605,242	2,446,188
LIABILITIES
Junior Subordinated Obligations Issued to Unconsolidated Subsidiary Trusts	20,000	20,000
Other Liabilities	22,008	21,621
Total Liabilities	2,372,390	2,232,217
Equity [Abstract]
Stockholders' Equity Attributable to Parent	232,852	213,971	$ 200,926	$ 192,154
Total Liabilities and Stockholders' Equity	2,605,242	2,446,188
Parent Company [Member]
ASSETS
Interest-Bearing Deposits at Banks	3,593	3,441
Available-for-Sale	1,382	1,232
Held-to-Maturity (Approximate Fair Value of $343,751 at December 31, 2016, and $325,930 at December 31, 2015)	1,000	1,000
Equity Method Investments	243,031	225,934
Other Assets	7,951	7,390
Total Assets	256,957	238,997
LIABILITIES
Junior Subordinated Obligations Issued to Unconsolidated Subsidiary Trusts	20,000	20,000
Other Liabilities	4,105	5,026
Total Liabilities	24,105	25,026
Equity [Abstract]
Stockholders' Equity Attributable to Parent	232,852	213,971
Total Liabilities and Stockholders' Equity	$ 256,957	$ 238,997