Securities Sold under Agreement to Repurchase and Other Borrowings (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary of balances and interest rates
Average daily balance during the year	$ 90,608	$ 94,477	$ 97,717
Average interest rate during the year	4.01%	3.90%	3.55%
Maximum month end balance during the year	$ 90,616	$ 100,446	$ 98,815
Weighted average interest rate at year end	4.01%	4.01%	3.79%