Loans and Allowance for Loan Losses (Details 2) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Summary of amounts included in nonaccrual loans segregated by class of loans
Nonaccrual loans, Total	$ 20,702	$ 21,187	$ 22,469
Non-residential real estate [Member]
Summary of amounts included in nonaccrual loans segregated by class of loans
Nonaccrual loans, Total	9,711		9,235
Residential real estate [Member]
Summary of amounts included in nonaccrual loans segregated by class of loans
Nonaccrual loans, Total	4,098		5,860
Non-consumer non-real estate [Member]
Summary of amounts included in nonaccrual loans segregated by class of loans
Nonaccrual loans, Total	1,142		1,547
Consumer non-real estate [Member]
Summary of amounts included in nonaccrual loans segregated by class of loans
Nonaccrual loans, Total	140		178
Other loans [Member]
Summary of amounts included in nonaccrual loans segregated by class of loans
Nonaccrual loans, Total	1,918		4,285
Acquired loans [Member]
Summary of amounts included in nonaccrual loans segregated by class of loans
Nonaccrual loans, Total	$ 3,693		$ 1,364