Income Taxes (Details)	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Schedule of reconciliation of the United States federal statutory tax rate to the effective tax rate
Tax at U.S. statutory rate	35.00%	35.00%	35.00%	35.00%
Increase (decrease) in taxes resulting from:
Tax-exempt interest income	(7.58%)	(7.93%)	(8.41%)	(7.71%)
BOLI income	(4.18%)	(2.44%)	(3.30%)	(2.66%)
Investment tax credits, net of amortization	(2.19%)	(0.56%)	(0.72%)	(0.54%)
State income taxes, net of federal benefit	0.31%	(0.77%)	(0.03%)	(0.16%)
(Decrease)/increase to valuation allowance	(10.76%)	(1.30%)	(4.21%)	0.54%
Other items, net	0.21%	4.17%	0.81%	3.47%
Effective tax rate	10.81%	26.17%	19.14%	27.94%

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A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 47

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

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-Section 50

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

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-Subparagraph (SX 210.4-08.(h)(2))

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- Definition

The domestic federal statutory tax rate applicable under enacted tax laws to the Company's pretax income from continuing operations for the period. The "statutory" tax rate is the regular tax rate if there are alternative tax systems.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 47

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Subparagraph (SAB TOPIC 6.I)

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to changes in the valuation allowance for deferred tax assets.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to nondeductible life insurance premiums under enacted tax laws.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to all other items not otherwise listed in the existing taxonomy.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by investment tax credits generated or utilized under enacted tax laws during the period.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to income that is exempt from income taxes under enacted tax laws.

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The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate attributable to state and local income tax settlements during the period.

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