INVESTMENT OPERATIONS - Summary of Net Realized Investment Gains (Losses) for All Other Investments (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Fixed maturities	$ 2,681	$ 15,686	$ 44,298	$ 21,885
Equity securities	16,918	6,117	(652)	44,292
Modco trading portfolios	44,918	67,674	108,223	252,147
Net credit losses recognized in earnings	(38,459)		(120,540)
Net impairment losses recognized in operations		(10,818)		(14,658)
Commercial mortgage loans	(2,174)	(1,575)	(101,256)	(1,435)
Other investments	(1,065)	315	(2,825)	365
Realized gains (losses) - investments	22,819	77,399	(72,752)	302,596
Realized gains (losses) - derivatives	15,337	42,286	92,899	(86,288)
Realized gains (losses) - investments/derivatives	$ 38,156	$ 119,685	$ 20,147	$ 216,308

Realized Investment Gains (Losses), All Investments

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Represents the total realized gain (loss) included in earnings during the period as a result of investments other than derivative financial instruments, net of the amount recognized in earnings for other than temporary impairments (OTTI) of investments in debt and equity securities.

+ References

No definition available.

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- Definition

Amount of expense for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), for which no credit loss was previously recorded.

+ References

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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in net income (trading).

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Amount of unrealized and realized gain (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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- Definition

Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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The gains (losses) included in earnings that represent the difference between the sale price and the carrying value of loans made to finance real estate acquisitions. This element refers to the gain (loss) and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

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Amount of gain (loss) included in earnings for investments classified as other.

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Amount of realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI).

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Amount of other-than-temporary impairment (OTTI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), recognized in earnings and other comprehensive loss (OCI).

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