Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Income tax reconciliation, amount
Expected tax (benefit) expense			$ (79,109)	$ 52,386
Adjustments:
Tax-exempt interest			(38,512)	(44,421)
Dividends received deduction			(1,407)	(772)
Effective tax rate method adjustment				15,619
Other			2,273	478
Actual tax (benefit) expense	$ 13,855	$ 20,085	$ (116,755)	$ 23,290
Income tax reconciliation, percent of income (loss) before income taxes
Expected tax (benefit) expense (as a percent)			35.00%	35.00%
Adjustments:
Tax-exempt interest (as a percent)			17.10%	(29.70%)
Dividends received deduction (as a percent)			0.60%	(0.50%)
Effective tax rate method adjustment (as a percent)				10.50%
Other (as a percent)			(1.00%)	0.30%
Actual Tax Expense (as a percent)			51.70%	15.60%

The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit that is attributable to effective tax rate method adjustment. Under the effective tax rate method, the estimated full year effective tax rate is applied to the interim year-to-date income before income taxes to determine the income tax expense for the year-to-date period.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to the application of the effective tax rate method. Under the effective tax rate method, the estimated full year effective tax rate is applied to the interim year-to-date income before income taxes to determine the income tax expense for the year-to-date period.

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

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The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to the deduction for dividends paid or received under enacted tax laws.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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The portion of the difference, between total income tax expense or benefit as reported in the Income Statement for the year/accounting period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations, that is attributable to all other items not otherwise listed in the existing taxonomy.

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The portion of the difference between total income tax expense or benefit as reported in the Income Statement for the period and the expected income tax expense or benefit computed by applying the domestic federal statutory income tax rates to pretax income from continuing operations attributable to income that is exempt from income taxes under enacted tax laws.

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