MONY CLOSED BLOCK OF BUSINESS - Summary of Financial Information of the Policyholder Dividend Obligation (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2018
Closed block liabilities
Future policy benefits, policyholders’ account balances and other policyholder liabilities	$ 5,458,772	$ 5,836,815
Policyholder dividend obligation	473,380	278,505	$ 319,865	$ 0
Other liabilities	8,328	11,247
Total closed block liabilities	5,940,480	6,126,567
Closed block assets
Fixed maturities, available-for-sale, at fair value	4,827,002	4,682,731
Commercial mortgage loans	69,422	72,829
Policy loans	633,609	640,134
Cash and other invested assets	24,614	44,877
Other assets	96,865	107,177
Total closed block assets	5,651,512	5,547,748
Excess of reported closed block liabilities over closed block assets	288,968	578,819
Portion of above representing accumulated other comprehensive income:
Net unrealized gains (losses) - investments/derivatives net of policyholder dividend obligation: 2020 - $383,309 and 2019 - $167,285; and net of income tax: 2020 - $(80,495) and 2019 - $(35,130)	0	0
Future earnings to be recognized from closed block assets and closed block liabilities	288,968	578,819
Policyholder dividend obligations	383,309	167,285
Income tax expense (benefit)	$ (80,495)	$ (35,130)

Represents the amount of cash and other invested assets held by the closed block.

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Amount of unrealized gain (loss) on investments that were allocated to the closed block, net of deferred tax benefits.

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Amount of deferred income tax expense (benefit) pertaining to policyholder dividend obligation.

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Represents the amount of future policy benefits, policyholders' account balances and other to be paid as of the balance sheet date to policyholders of contracts in the closed block.

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The sum of cash, cash equivalents, investments and other assets allocated to the segregated group of participating or dividend-paying policies and contracts identified as the closed block.

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Fair value of investments in debt securities that are deemed to be available for sale that are allocated to the segregated group of participating or dividend-paying policies and contracts identified as the closed block. Change in fair of such securities is a component of change in other comprehensive income in the period, which is reflected in the closed block disclosure.

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Carrying amount of investments in mortgage loans on real estate allocated to the segregated group of participating or dividend-paying policies and contracts identified as the closed block.

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Amount of other assets held by the closed block. Excludes other investments.

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Carrying amount of loans to policy holders secured by benefits under insurance policies that are allocated to the segregated group of participating or dividend-paying policies and contracts identified as the closed block.

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The carrying amount of closed block liabilities in excess of the carrying amount of closed block assets at the date of demutualization (adjusted to eliminate the impact of related amounts in accumulated other comprehensive income).

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The net increase or decrease in the period in the fair value of the fixed maturity and equity investments designated as available for sale as of the balance sheet date that were allocated to the segregated group of participating or dividend-paying policies and contracts identified as a closed block. Also a component of change in other comprehensive income in the period, which is reflected in the closed block disclosure.

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For the segregated group of participating or dividend-paying policies and contracts along with the assets backing them (known as a closed block), the total of future policy benefits, policyholder account balance, policyholder dividend obligation and any other closed block liabilities.

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Amount of liabilities allocated to the closed block, classified as other.

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The liability as of the balance sheet date for the excess of the cumulative actual closed block earnings over the cumulative expected (actuarially determined) closed block earnings (each) for the period from the actuarial calculation date to the date of measurement. The excess will result in future dividends to closed block policyholders, unless offset by less favorable than expected future performance of the closed block. The policyholder dividend obligation, which may not have a negative balance, recognizes that a portion of earnings in certain cases will not inure to the stockholders of the insurance entity.

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The difference between the liabilities of and the assets allocated to the segregated group of participating or dividend-paying policies and contracts identified as the closed block.

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