FAIR VALUE OF FINANCIAL INSTRUMENTS (Carrying Value and Estimated Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale, at fair value (amortized cost $150 in 2019 and $150 in 2018)	$ 1,719,607	$ 1,749,488
Investments
Trading securities	15,256	13,240
Equity securities:	299,203	248,361
Mortgage loans	42,448	25,782
Fair Value
Investments
Equity securities:	299,203	248,361
Mortgage loans	43,992	26,021
Other long-term investments	78,410	37,077
Short-term investments	175	175
Cash and cash equivalents	120,722	64,454
Corporate-owned life insurance	6,777	4,907
Fair Value \| Fixed maturities:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale, at fair value (amortized cost $150 in 2019 and $150 in 2018)	1,719,607	1,749,488
Investments
Trading securities	15,256	13,240
Carrying Value
Investments
Equity securities:	299,203	248,361
Mortgage loans	42,448	25,782
Other long-term investments	78,410	37,077
Short-term investments	175	175
Cash and cash equivalents	120,722	64,454
Corporate-owned life insurance	6,777	4,907
Carrying Value \| Fixed maturities:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale, at fair value (amortized cost $150 in 2019 and $150 in 2018)	1,719,607	1,749,488
Investments
Trading securities	$ 15,256	$ 13,240

Other Long-term Investments, Fair Value Disclosure

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Short-term Investments, Fair Value Disclosure

+ References

No definition available.

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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
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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Fair value portion of the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

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- Definition

Amount of 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 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740

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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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The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(c))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

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- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.4)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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