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, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Closed block liabilities
Future policy benefits, policyholders’ account balances and other policyholder liabilities	$ 5,579,389	$ 5,679,732
Policyholder dividend obligation	319,865	0	$ 0	$ 160,712
Other liabilities	11,366	22,505
Total closed block liabilities	5,910,620	5,702,237
Closed block assets
Fixed maturities, available-for-sale, at fair value	4,694,274	4,257,437
Mortgage loans on real estate	73,563	75,838
Policy loans	648,805	672,213
Cash	75,828	116,225
Other assets	106,481	136,388
Total closed block assets	5,598,951	5,258,101
Excess of reported closed block liabilities over closed block assets	311,669	444,136
Portion of above representing accumulated other comprehensive income:
Net unrealized investment gains (losses) net of policyholder dividend obligation: $198,285 and $(141,128); and net of income tax: $(41,640) and $61,676	0	(120,528)
Future earnings to be recognized from closed block assets and closed block liabilities	311,669	323,608
Policyholder dividend obligations	198,285	(141,128)
Deferred income tax expense (benefit)	$ (41,640)	$ 61,676