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Federal Income Taxes (Reconciliation of Federal Income Tax on Income at the Corporate Rate to the Effective Tax Rate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Tax at statutory rate	$ 58,839	$ 106,115	$ 63,627
Tax-advantaged interest	(4,087)	(4,514)	(4,730)
Dividends received deduction	(469)	(558)	(514)
Executive compensation	1,848	2,469	2,246
Stock-based compensation	(893)	(693)	(1,846)
Other	62	(1,346)	(2,150)
Total federal income tax expense	55,300	101,473	56,633
Income available to common stockholders, before federal income tax	$ 270,986	$ 495,957	$ 302,988
Effective Income Tax Rate Reconciliation, Percent	20.40%	20.50%	18.70%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%

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The federal income tax expense (benefit) related to executive compensation.

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Amount of income (loss) from continuing operations available to common stockholders, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest

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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 investment income that is tax advantaged. Tax advantaged investment securities generally are, by statute, tax-reduced, tax-deferred, or tax-free.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for award under share-based payment arrangement. Includes, but is not limited to, expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other adjustments.

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