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Fair Value Measurements (Changes in Fair Value of Securities Using Level 3 Inputs) (Details) - Available-for-sale Securities [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Net Investment Income Earned [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total net (losses) gains for the period included in net income	$ (1,283)
Corporate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Beginning Balance	17,051	$ 0
Total net (losses) gains for the period included in OCI	(785)	(118)
Total net (losses) gains for the period included in net income	21
Purchases	46,150	0
Sales	0	0
Issuances	0	0
Settlements	(283)	0
Transfers into Level 3	9,592	17,169
Transfers out of Level 3	0	0
Fair Value, Ending Balance	70,700	17,051
Period change unrealized gains (losses) in earnings	(1,046)	0
Period change unrealized gains (losses) in OCI	(785)
Corporate Securities [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total net (losses) gains for the period included in net income		0
Corporate Securities [Member] | Net Investment Income Earned [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total net (losses) gains for the period included in net income	(1,046)	0
Collateralized Loan Obligations and Other Asset-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Beginning Balance	17,034	7,409
Total net (losses) gains for the period included in OCI	1,883	(261)
Total net (losses) gains for the period included in net income	6
Purchases	25,785	21,282
Sales	0	0
Issuances	0	0
Settlements	(2,638)	(279)
Transfers into Level 3	31,520	18,853
Transfers out of Level 3	(16,978)	30,215
Fair Value, Ending Balance	56,375	17,034
Period change unrealized gains (losses) in earnings	(237)	0
Period change unrealized gains (losses) in OCI	1,883
Collateralized Loan Obligations and Other Asset-Backed Securities [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total net (losses) gains for the period included in net income		0
Collateralized Loan Obligations and Other Asset-Backed Securities [Member] | Net Investment Income Earned [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total net (losses) gains for the period included in net income	(237)	245
Obligations of States and Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Beginning Balance	0
Total net (losses) gains for the period included in OCI	4
Purchases	0
Sales	0
Issuances	0
Settlements	0
Transfers into Level 3	2,890
Transfers out of Level 3	0
Fair Value, Ending Balance	2,894	0
Period change unrealized gains (losses) in earnings	0
Period change unrealized gains (losses) in OCI	4
Obligations of States and Political Subdivisions [Member] | Net Investment Income Earned [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total net (losses) gains for the period included in net income	0
Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Beginning Balance	34,085	7,409
Total net (losses) gains for the period included in OCI	1,102	(379)
Purchases	71,935	21,282
Sales	0	0
Issuances	0	0
Settlements	(2,921)	(279)
Transfers into Level 3	44,002	36,022
Transfers out of Level 3	(16,978)	30,215
Fair Value, Ending Balance	129,969	34,085
Period change unrealized gains (losses) in earnings	(1,283)	0
Period change unrealized gains (losses) in OCI	1,102
Investments [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total net (losses) gains for the period included in net income		0
Investments [Member] | Net Investment Income Earned [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total net (losses) gains for the period included in net income	$ 27	$ 245

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Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

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Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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