Derivatives (Schedule Of Interest Rate Swaps) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Derivative [Line Items]
Estimated fair value of liability	$ 13,531	$ 9,492	$ 14,263
Interest Rate Swap Hedging Variable Rate Exposure On Trust Preferred Securities 2006-2011 [Member]
Derivative [Line Items]
Notional amount for all periods	115,000	115,000	115,000
Estimated fair value of liability	0	2,873	4,304
Interest Rate Swap Hedging Variable Rate Exposure On Trust Preferred Securities 2011-2016 [Member]
Derivative [Line Items]
Notional amount for all periods	115,000	115,000	115,000
Estimated fair value of liability	$ 13,531	$ 6,619	$ 9,959

Aggregate notional amount of all interest rate derivatives designated as hedging instruments in cash flow hedges. Notional amount refers to the monetary amount specified in the interest rate derivative contract.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5579245-113959

Name:	us-gaap_NotionalAmountOfInterestRateCashFlowHedgeDerivatives
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant