Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2021

Accounting Policies [Abstract]

Schedule of Goodwill and Intangible Assets

	September 30,		December 31,
(in thousands)	2021		2020
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
Definite-lived intangibles, net of accumulated amortization of $4,035 at 9/30/21 and $3,878 at 12/31/20		-		157
Total intangibles	$	7,500	$	7,657
Total goodwill and intangibles	$	53,562	$	53,719

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 September 30, 2021						Ended September 30, 2020
	Income		Shares		Per Share		Income		Shares		Per Share
(in thousands, except per share data)	(Numerator)		(Denominator)		Amount		(Numerator)		(Denominator)		Amount
Basic EPS
Earnings available to common shareholders	$	29,243		45,243	$	0.65	$	42,387		45,014	$	0.94
Effect of Dilutive Securities
Stock options and restricted stock units		—		446				—		412
Diluted EPS
Earnings available to common shareholders	$	29,243		45,689	$	0.64	$	42,387		45,426	$	0.93
Anti-dilutive options excluded from diluted EPS				191						339
	For the Nine Months						For the Nine Months
	Ended September 30, 2021						Ended September 30, 2020
	Income		Shares		Per Share		Income		Shares		Per Share
(in thousands, except per share data)	(Numerator)		(Denominator)		Amount		(Numerator)		(Denominator)		Amount
Basic EPS
Earnings available to common shareholders	$	184,070		45,216	$	4.07	$	73,286		44,962	$	1.63
Effect of Dilutive Securities
Stock options and restricted stock units		—		498				—		377
Diluted EPS
Earnings available to common shareholders	$	184,070		45,714	$	4.03	$	73,286		45,339	$	1.62
Anti-dilutive options excluded from diluted EPS				191						339

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

(in thousands)	For the Three Months						For the Nine Months
	Ended September 30,						Ended September 30,
Unrealized Gains/Losses on Available-for-Sale Securities	2021			2020			2021			2020
Beginning balance	$	79,144		$	93,035		$	108,714		$	52,473
Cumulative-effect adjustment of ASU 2016-13		—			—			—			22
Adjusted beginning balance	$	79,144		$	93,035		$	108,714		$	52,495
Other comprehensive earnings (loss) before reclassifications		(12,114	)		10,412			(40,307	)		52,264
Amounts reclassified from accumulated other comprehensive earnings		(126	)		(862	)		(1,503	)		(2,174	)
Net current-period other comprehensive earnings (loss)	$	(12,240	)	$	9,550		$	(41,810	)	$	50,090
Ending balance	$	66,904		$	102,585		$	66,904		$	102,585
Balance of securities for which an allowance for credit losses has been recognized in net earnings							$	426		$	795

Schedule of Effects of Reclassifications out of Accumulated Other Comprehensive Earnings

	Amount Reclassified from Accumulated Other
(in thousands)	Comprehensive Earnings
	For the Three Months						For the Nine Months
Component of Accumulated	Ended September 30,						Ended September 30,								Affected line item in the
Other Comprehensive Earnings	2021			2020			2021				2020				Statement of Earnings
Unrealized gains and losses on available-for-sale securities	$	182		$	738			$	1,731			$	3,356		Net realized gains
		(22	)		353				171				(604	)	Credit losses presented within net realized gains
	$	160		$	1,091			$	1,902			$	2,752		Earnings before income taxes
		(34	)		(229	)			(399	)			(578	)	Income tax expense
	$	126		$	862			$	1,503			$	2,174		Net earnings