Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2022

Accounting Policies [Abstract]

Schedule of Goodwill and Intangible Assets

	June 30,		December 31,
(in thousands)	2022		2021
Goodwill
Surety	$	40,816	$	40,816
Casualty		5,246		5,246
Total goodwill	$	46,062	$	46,062
Intangibles
Indefinite-lived intangibles - state insurance licenses		7,500		7,500
Total goodwill and intangibles	$	53,562	$	53,562

Schedule of Reconciliation of Numerator and Denominator of the Basic and Diluted Earnings Per Share Computations

	For the Three Months								For the Three Months
	Ended June 30, 2022								Ended June 30, 2021
	Income			Shares		Per Share			Income		Shares		Per Share
(in thousands, except per share data)	(Numerator)			(Denominator)		Amount			(Numerator)		(Denominator)		Amount
Basic EPS
Earnings (loss) available to common shareholders	$	(2,239	)		45,354	$	(0.05	)	$	81,815		45,226	$	1.81
Effect of Dilutive Securities
Stock options and restricted stock units		—			—					—		489
Diluted EPS
Earnings (loss) available to common shareholders	$	(2,239	)		45,354	$	(0.05	)	$	81,815		45,715	$	1.79
Anti-dilutive securities excluded from diluted EPS					736							169
	For the Six Months								For the Six Months
	Ended June 30, 2022								Ended June 30, 2021
	Income			Shares		Per Share			Income		Shares		Per Share
(in thousands, except per share data)	(Numerator)			(Denominator)		Amount			(Numerator)		(Denominator)		Amount
Basic EPS
Earnings (loss) available to common shareholders	$	45,684			45,330	$	1.01		$	154,827		45,202	$	3.43
Effect of Dilutive Securities
Stock options and restricted stock units		—			418					—		501
Diluted EPS
Earnings (loss) available to common shareholders	$	45,684			45,748	$	1.00		$	154,827		45,703	$	3.39
Anti-dilutive securities excluded from diluted EPS					436							169

Schedule of Changes in the Balance of Each Component of Accumulated Other Comprehensive Earnings (Loss)

(in thousands)	For the Three Months						For the Six Months
	Ended June 30,						Ended June 30,
Unrealized Gains/Losses on Available-for-Sale Securities	2022			2021			2022			2021
Beginning balance	$	(65,755	)	$	63,967		$	49,826		$	108,714
Other comprehensive earnings (loss) before reclassifications		(97,894	)		15,601			(213,636	)		(28,194	)
Amounts reclassified from accumulated other comprehensive earnings		331			(424	)		492			(1,376	)
Net current-period other comprehensive earnings (loss)	$	(97,563	)	$	15,177		$	(213,144	)	$	(29,570	)
Ending balance	$	(163,318	)	$	79,144		$	(163,318	)	$	79,144
Balance of securities for which an allowance for credit losses has been recognized in net earnings							$	1,083		$	321

Schedule of Effects of Reclassifications out of Accumulated Other Comprehensive Earnings (Loss)

	Amount Reclassified from Accumulated Other
(in thousands)	Comprehensive Earnings (Loss)
	For the Three Months						For the Six Months
Component of Accumulated	Ended June 30,						Ended June 30,						Affected line item in the
Other Comprehensive Earnings (Loss)	2022			2021			2022			2021			Statement of Earnings
Unrealized gains and losses on available-for-sale securities	$	(722	)	$	366		$	(772	)	$	1,549		Net realized gains (losses)
		303			171			149			193		Credit gains presented within net realized gains
	$	(419	)	$	537		$	(623	)	$	1,742		Earnings (loss) before income taxes
		88			(113	)		131			(366	)	Income tax (expense) benefit
	$	(331	)	$	424		$	(492	)	$	1,376		Net earnings (loss)