Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Mortgage Loans:
Mortgages Held-for-sale, Fair Value Disclosure	$ 15,327	$ 9,263
Investment Securities:
Available for sale securities, pledged	$ 662,515	$ 568,553
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	102,003,046
Treasury stock, shares	276,968	364,711