Fair Value Measurements - Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Assets:
Fair Value	$ 282,855	$ 217,151
Equity securities at fair value	37,649	22,328
U.S. Governments
Assets:
Fair Value	16,195	13,679
States, territories, and possession
Assets:
Fair Value	3,186	2,445
Political subdivisions
Assets:
Fair Value	2,397	1,942
Special revenue excluding mortgage/asset-backed securities
Assets:
Fair Value	28,898	18,436
Industrial and miscellaneous
Assets:
Fair Value	158,767	129,013
Mortgage/asset-backed securities
Assets:
Fair Value	73,412	51,636
Fair Value, Measurements, Recurring
Assets:
Equity securities at fair value	37,649	22,328
Cash, cash equivalents, and restricted cash	109,942	33,349
Total assets	430,446	272,828
Fair Value, Measurements, Recurring \| U.S. Governments
Assets:
Fair Value	16,195	13,679
Fair Value, Measurements, Recurring \| States, territories, and possession
Assets:
Fair Value	3,186	2,445
Fair Value, Measurements, Recurring \| Political subdivisions
Assets:
Fair Value	2,397	1,942
Fair Value, Measurements, Recurring \| Special revenue excluding mortgage/asset-backed securities
Assets:
Fair Value	28,898	18,436
Fair Value, Measurements, Recurring \| Industrial and miscellaneous
Assets:
Fair Value	158,767	129,013
Fair Value, Measurements, Recurring \| Mortgage/asset-backed securities
Assets:
Fair Value	73,412	51,636
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 1
Assets:
Equity securities at fair value	37,649
Cash, cash equivalents, and restricted cash	109,942	28,350
Total assets	147,591	28,350
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2
Assets:
Equity securities at fair value		22,328
Cash, cash equivalents, and restricted cash		4,999
Total assets	282,855	242,978
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| U.S. Governments
Assets:
Fair Value	16,195	13,679
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| States, territories, and possession
Assets:
Fair Value	3,186	2,445
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| Political subdivisions
Assets:
Fair Value	2,397	1,942
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| Special revenue excluding mortgage/asset-backed securities
Assets:
Fair Value	28,898	18,436
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| Industrial and miscellaneous
Assets:
Fair Value	158,767	129,013
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 2 \| Mortgage/asset-backed securities
Assets:
Fair Value	73,412	50,136
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 3
Assets:
Total assets		1,500
Fair Value, Measurements, Recurring \| Fair Value, Inputs, Level 3 \| Mortgage/asset-backed securities
Assets:
Fair Value	$ 0	$ 1,500

Fair value portion of cash, cash equivalents and restricted cash.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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