Consolidated Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Mortgage Loans:
Mortgages Held-for-sale, Fair Value Disclosure	$ 6,480,000	$ 15,327,000
Investment Securities:
Available-for-sale Securities Pledged as Collateral	$ 659,378,000	$ 662,515,000
Stockholders' Equity:
Preferred stock, par value	$ 1.00	$ 1.00
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	6,000	6,000
Common stock, par value	$ 5.00	$ 5.00
Common Stock, Shares Authorized	120,000,000	120,000,000
Common stock, shares issued	107,081,397	107,081,397
Treasury stock, shares	272,802	276,968