Comprehensive Income (Schedule Of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010	Dec. 31, 2009
Comprehensive Income
AOCI, Unrealized gains on available-for-sale securities	$ 50,055	$ 35,465	$ 31,962	$ 19,789
Other Comprehensive Income, Unrealized gains on available-for-sale securities	18,093	15,676
AOCI, Unrealized losses on securities for which other-than-temporary-impairment has been recognized	(28,926)	(28,173)	(28,173)	(27,501)
Other Comprehensive Income, Unrealized losses on securities for which other-than-temporary-impairment has been recognized	(753)	(672)
AOCI, Unrealized gains (losses) on held to maturity securities	5,087	6,172	5,667	812
Other Comprehensive Income, Unrealized gains (losses) on held-to-maturity securities	(580)	5,360
AOCI, Unrecognized gain (loss) on cash flow hedges	568	868	846	187
Other Comprehensive Income, Unrecognized gain (loss) on cash flow hedges	(278)	681
AOCI, Defined benefit pension plans	(10,382)	(13,172)	(11,571)	(13,653)
Comprehensive income	1,189	481
Accumulated other comprehensive income (loss), net of tax	16,402	1,160	(1,269)	(20,366)
Other Comprehensive Income, Accumulated other comprehensive income (loss)	$ 17,671	$ 21,526

Other Comprehensive Income Temporary Impairment

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Other Comprehensive Income Unrealized Gains Losses On Available For Sale Of Securities

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Other Comprehensive Income Unrealized Gains Losses On Cash Flow Hedges

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Other Comprehensive Income Unrealized Gains Losses On Held To Maturity

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Other Comprehensive Plan Benefit Plans

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The after-tax amount of other than temporary impairment (OTTI) loss on a debt security, categorized as Held-to-maturity, related to factors other than credit losses when the entity does not intend to sell the security and it is not more likely than not that the entity will be required to sell the security before recovery of its amortized cost basis. This amount of other than temporary losses on Held-to-maturity Securities, net of applicable taxes, is the portion attributable to the parent.

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Amount of unrealized gain (loss) related to the increase or decrease in fair value of interest rate derivatives designated as cash flow hedging instruments, which was recorded in accumulated other comprehensive income to the extent that the cash flow hedge was determined to be effective.

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Unrealized Gains(Losses) on Held to maturity Securities

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Accumulated appreciation or loss, net of tax, in value of the total of unsold securities at the end of an accounting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 130
-Paragraph 26

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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at fiscal year-end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, and unrealized gains and losses on certain investments in debt and equity securities as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 12
-Paragraph 10

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 31
-Article 5

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Net changes to accumulated comprehensive income during the period related to benefit plans, after tax, attributable to the parent entity.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 38
-Subparagraph c(3)

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
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Tax effect of the change in accumulated other comprehensive income, that is, the tax effect on items included in other comprehensive income during the period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-Subparagraph b

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-Name Accounting Research Bulletin (ARB)
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-Name Accounting Principles Board Opinion (APB)
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-Name Statement of Financial Accounting Standard (FAS)
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
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