CONSOLIDATED CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Investment securities held to maturity - fair value	$ 655,445	$ 632,380
Loans - allowance for loan losses	$ 62,086	$ 62,453
Common Stock, stated value (in dollars per share)	$ 0.125	$ 0.125
Common Stock, Authorized (in shares)	50,000,000	50,000,000
Common Stock, Issued (in shares)	40,749,340	40,664,259
Common Stock, Outstanding (in shares)	40,749,340	40,664,259
Preferred Stock, par value (in dollars per share)	$ 1,000	$ 1,000
Preferred Stock, liquidation value per share (in dollars per share)	$ 1,000	$ 1,000
Preferred Stock, Authorized (in shares)	600	600
Preferred Stock, Issued (in shares)	125	125
Preferred Stock, Outstanding (in shares)	125	125