MORTGAGE LOANS - Impaired Loans (Details) - Commercial mortgage loans - Successor - USD ($) $ in Thousands	11 Months Ended	12 Months Ended
Dec. 31, 2015	Dec. 31, 2016
Recorded Investment
With no related allowance recorded, recorded investment	$ 1,694	$ 0
With an allowance recorded, recorded investment	0	1,819
Unpaid Principal Balance
With no related allowance recorded, unpaid principal balance	1,728	0
With an allowance recorded, unpaid principal balance	0	1,819
Related Allowance
With an allowance recorded, related allowance	0	724
Average Recorded Investment
With no related allowance recorded, average recorded investment	847	0
With an allowance recorded, average recorded investment	0	1,819
Interest Income Recognized
With no related allowance recorded, interest income recognized	104	0
With an allowance recorded, interest income recognized	0	96
Cash Basis Interest Income
With no related allowance recorded, cash basis interest income	117	0
With an allowance recorded, cash basis interest income	$ 0	$ 96

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-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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