Consolidated Condensed Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Securities available-for-sale, amortized cost	$ 1,067,835	$ 1,099,658
Securities held-to-maturity, fair value	$ 238,519	$ 410,705
Common stock no par value
Common stock shares authorized	20,000,000	20,000,000
Common stock shares issued	16,150,966	16,150,987
Treasury stock shares	738,989	738,989