Deposits (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Maturities of Time Deposits [Abstract]
Within one year	$ 454,235,000
After one but within two years	326,502,000
After two but within three years	109,348,000
After three but within four years	49,222,000
After four but within five years	35,972,000
After five years	7,982,000
Total	983,261,000	933,127,000
Time Deposits, $100,000 or More [Abstract]
Time deposits of $100,000 or more	$ 352,300,000	$ 305,700,000