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Fair Value Measurements (Change in Fair Value of Securities Using Level 3 Inputs) (Details) - Available-for-sale Securities [Member] - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2021 | Mar. 31, 2020
Obligations of States and Political Subdivisions [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value, December 31, | $ 2,894 | $ 0
Total net (losses) gains for the period included in OCI | (99) | 0
Purchases | 0 | 0
Sales | 0 | 0
Issuances | 0 | 0
Settlements | 0 | 0
Transfers into Level 3 | 5,101 | 2,890
Transfers out of Level 3 | 0 | 0
Fair value, March 31 | 7,896 | 2,890
Period change unrealized (losses) gains in earnings for assets held at period end | 0 | 0
Period change unrealized gains (losses) in OCI for assets held at period end | (99) | 0
Corporate Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value, December 31, | 70,700 | 17,051
Total net (losses) gains for the period included in OCI | (2,388) | 1
Purchases | 21,100 | 3,002
Sales | 0 | 0
Issuances | 0 | 0
Settlements | 0 | 0
Transfers into Level 3 | 0 | 4,192
Transfers out of Level 3 | 0 | 0
Fair value, March 31 | 89,322 | 24,185
Period change unrealized (losses) gains in earnings for assets held at period end | (91) | (61)
Period change unrealized gains (losses) in OCI for assets held at period end | (2,388) | 1
Collateralized Loan Obligations and Other Asset Backed Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value, December 31, | 56,375 | 17,034
Total net (losses) gains for the period included in OCI | (1,116) | (1,756)
Purchases | 10,672 | 4,831
Sales | 0 | 0
Issuances | 0 | 0
Settlements | (412) | 0
Transfers into Level 3 | 0 | 20,107
Transfers out of Level 3 | (490) | (3,630)
Fair value, March 31 | 64,889 | 36,372
Period change unrealized (losses) gains in earnings for assets held at period end | (143) | (214)
Period change unrealized gains (losses) in OCI for assets held at period end | (1,116) | (1,756)
Investments [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Fair value, December 31, | 129,969 | 34,085
Total net (losses) gains for the period included in OCI | (3,603) | (1,755)
Purchases | 31,772 | 7,833
Sales | 0 | 0
Issuances | 0 | 0
Settlements | (412) | 0
Transfers into Level 3 | 5,101 | 27,189
Transfers out of Level 3 | (490) | (3,630)
Fair value, March 31 | 162,107 | 63,447
Period change unrealized (losses) gains in earnings for assets held at period end | (234) | (275)
Period change unrealized gains (losses) in OCI for assets held at period end | (3,603) | (1,755)
Gain (Loss) on Investments [Member] | Obligations of States and Political Subdivisions [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 | 0
Gain (Loss) on Investments [Member] | Corporate Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Total net (losses) gains for the period included in net income | (91) | (61)
Gain (Loss) on Investments [Member] | Collateralized Loan Obligations and Other Asset Backed Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Total net (losses) gains for the period included in net income | (143) | (214)
Gain (Loss) on Investments [Member] | 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 | (234) | (275)
Net Investment Income Earned [Member] | Obligations of States and Political Subdivisions [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 | 0
Net Investment Income Earned [Member] | Corporate Securities [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 | 0
Net Investment Income Earned [Member] | Collateralized Loan Obligations and Other Asset Backed Securities [Member] |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] |  |
Total net (losses) gains for the period included in net income | 3 | 0
Net Investment Income Earned [Member] | 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 | $ 4 | $ 0

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- Definition Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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