Income Taxes - Reconciliation of Effective Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Expected federal tax on income	$ 33,512	$ 49,654	$ 4,103
Add (deduct) tax effects of:
Tax-exempt interest	(4,203)	(4,159)	(3,726)
Dividend received deduction	(1,475)	(1,392)	(412)
Goodwill impairment	187	5,885	0
CARES Act net operating loss carryback	(2,792)	0	0
Employee share-based compensation	(541)	272	(1,134)
Compensation deduction limitation	663	680	1,754
Prior year adjustments	(219)	(716)	300
Other, net	1,136	1,782	309
Total income tax expense	$ 26,268	$ 52,006	$ 1,194

Effective Income Tax Rate Reconciliation, CARES Act Net Operating Loss Carryback, Amount

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Effective Tax Rate Reconciliation, Nondeductible Expense, Compensation Deduction Limitation, Amount

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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 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 deduction for dividend.

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