Securities (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 security	Dec. 31, 2011
Schedule of Securities [Line Items]
Securities pledged to secure public deposits, trust deposits, and for other purposes, carrying value	$ 587,865	$ 547,727
Securities pledged as collateral for short-term borrowings, carrying value	747,289	680,212
Number of pooled issue securities	29
Recover rate of banks	10.00%
Recover rate of insurance companies	15.00%
Number of single issue securities	6
Estimated fair value of single-issue trust preferred securities	7,786
Percent of municipal bond portfolio, general obligation bonds	99.50%
Estimated fair value of pooled trust preferred securities	24,192
Number of non-performing investments	9
Number of performing investments	3
Municipal bond portfolio, value	182,881
Purchase of non-agency collateralized mortgage obligations from 2003 through 2005	161,151
Purchase of additional non-agency collateralized mortgage obligations	42,870
Retained non-agency collateralized mortgage obligations	4,298
Sale of non-agency collateralized mortgage obligations	38,572
Book value of non-agency collateralized mortgage obligations	23,518
Percent of municipal bond portfolio rated A or better	99.80%
Percent of municipal bonds from Pennsylvania	76.80%
Average holding size of municipal bond	1,010
Percent of portfolio with credit support	77.40%
Non-agency collateralized mortgage obligations paydown balance on maturity	2,704
Annualized payout rate	37.70%
Original credit score	724
Ratio of original average loan-to-value	66.10%
Credit-related loss recognized	226
Accreted income	133
U.S. Treasury And Other U.S. Government Agencies And Corporations [Member]
Schedule of Securities [Line Items]
Securities with unrealized losses for less than 12 months	10
Residential Mortgage-Backed Securities [Member]
Schedule of Securities [Line Items]
Securities with unrealized losses for less than 12 months	15
Securities with unrealized losses of greater than 12 months	1
Agency Mortgage-Backed Securities [Member]
Schedule of Securities [Line Items]
Securities with unrealized losses for less than 12 months	10
Agency Collateralized Mortgage Obligations [Member]
Schedule of Securities [Line Items]
Securities with unrealized losses for less than 12 months	1
Non-Agency Collateralized Mortgage Obligations [Member]
Schedule of Securities [Line Items]
Securities with unrealized losses for less than 12 months	4
Book value of non-agency collateralized mortgage obligations sold	$ 2,848
Senior Tranche [Member]
Schedule of Securities [Line Items]
Number of single issue securities	2
States Of The U.S. And Political Subdivisions [Member]
Schedule of Securities [Line Items]
Securities with unrealized losses for less than 12 months	3
Collateralized Debt Obligations [Member]
Schedule of Securities [Line Items]
Securities with unrealized losses for less than 12 months	8
Securities with unrealized losses of greater than 12 months	13
Other Debt Securities [Member]
Schedule of Securities [Line Items]
Securities with unrealized losses of greater than 12 months	5
Equity Securities [Member]
Schedule of Securities [Line Items]
Securities with unrealized losses for less than 12 months	2
Mezzanine Tranches [Member]
Schedule of Securities [Line Items]
Number of pooled issue securities	27
Maximum [Member]
Schedule of Securities [Line Items]
Deferral rates after the deferral period ends maximum	90.00%
Range of credit loss	7.00%
Range of grown percentage of credit support due to paydowns and good credit performance	20.50%
Minimum [Member]
Schedule of Securities [Line Items]
Deferral rates after the deferral period ends	10.00%
Range of credit loss	2.00%
Range of grown percentage of credit support due to paydowns and good credit performance	4.00%