Loans and Leases (Troubled debt restructurings on financing receivables) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013 loans	Sep. 30, 2012 loans	Sep. 30, 2013 loans	Sep. 30, 2012 loans
Financing Receivable, Modifications [Line Items]
Number of loans	1	1	11	6
Pre-modification recorded investment	$ 65	$ 87	$ 21,377	$ 2,911
Post-modification recorded investment	65	87	21,377	2,911
Commercial
Financing Receivable, Modifications [Line Items]
Number of loans	0	0	3	0
Pre-modification recorded investment	0	0	17,873	0
Post-modification recorded investment	0	0	17,873	0
Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Number of loans	0	0	0	2
Pre-modification recorded investment	0	0	0	1,396
Post-modification recorded investment	0	0	0	1,396
Commercial and Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Number of loans	0	0	3	2
Pre-modification recorded investment	0	0	17,873	1,396
Post-modification recorded investment	0	0	17,873	1,396
Agricultural and Agricultural Real Estate
Financing Receivable, Modifications [Line Items]
Number of loans	0	0	3	2
Pre-modification recorded investment	0	0	2,576	276
Post-modification recorded investment	0	0	2,576	276
Residential Real Estate
Financing Receivable, Modifications [Line Items]
Number of loans	1	1	4	1
Pre-modification recorded investment	65	87	762	87
Post-modification recorded investment	65	87	762	87
Consumer
Financing Receivable, Modifications [Line Items]
Number of loans	0	0	1	1
Pre-modification recorded investment	0	0	166	1,152
Post-modification recorded investment	$ 0	$ 0	$ 166	$ 1,152