Investments in Equity Securities (Investments in Equity Securities Available for Sale) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Fair Value
Debt Securities, Available-for-sale [Line Items]
Cost	$ 1,115,328	$ 870,045
Gross unrealized gains	193,218	100,275
Gross unrealized losses	(122,652)	(29,077)
Equity securities	1,185,894	941,243
Fair Value \| Common stocks
Debt Securities, Available-for-sale [Line Items]
Cost	855,987	619,896
Gross unrealized gains	192,165	92,401
Gross unrealized losses	(65,401)	(16,894)
Equity securities	982,751	695,403
Fair Value \| Preferred stocks
Debt Securities, Available-for-sale [Line Items]
Cost	259,341	250,149
Gross unrealized gains	1,053	7,874
Gross unrealized losses	(57,251)	(12,183)
Equity securities	203,143	245,840
Carrying Value
Debt Securities, Available-for-sale [Line Items]
Equity securities	1,185,894	941,243
Carrying Value \| Common stocks
Debt Securities, Available-for-sale [Line Items]
Equity securities	982,751	695,403
Carrying Value \| Preferred stocks
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 203,143	$ 245,840

Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=123594786&loc=SL75136599-209740

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Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

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Amount of unrealized gain on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123583765&loc=SL75117546-209714

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Amount of unrealized loss on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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