Condensed Consolidated Statements of Condition (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Available-for-sale securities, at amortized cost	$ 1,434,468	$ 1,349,416	[1]
Held-to-maturity securities, fair value	24,062	25,163
Other borrowings, fair value	$ 11,424	$ 11,847
Common Stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common Stock, shares authorized (in shares)	25,000,000	25,000,000
Common Stock, shares issued (in shares)	14,635,468	14,426,711
Treasury stock, shares (in shares)	101,055	100,054

[1] Net of other-than-temporary impairment losses recognized in earnings.