MORTGAGE LOANS - Impaired Loans (Details) - Commercial mortgage loans - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2017	Dec. 31, 2016
Commercial mortgage loans:
Maximum number of days accrued interest on impaired loans	90 days
Recorded Investment
With no related allowance recorded	$ 1,235	$ 0
With an allowance recorded	9,573	1,819
Unpaid Principal Balance
With no related allowance recorded	1,186	0
With an allowance recorded	9,562	1,819
Related Allowance
With no allowance recorded	5,087	724
Average Recorded Investment
With no related allowance recorded	1,235	0
With an allowance recorded	9,573	1,819
Interest Income Recognized
With no related allowance recorded	0	0
With an allowance recorded	101	96
Cash Basis Interest Income
With no related allowance recorded	0	0
With an allowance recorded	$ 101	$ 96

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The maximum number of days of accrued interest that can be carried on an impaired loan.

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Amount of allowance for credit losses related to recorded investment.

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-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

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-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 15
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Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses.

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of interest income, recognized on accrual basis, on financing receivables that are recognized as impaired, for which there is no related allowance for credit losses.

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Amount of interest income, recognized on cash basis, on financing receivables, for which there is no related allowance for credit losses and are recognized as impaired.

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Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

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Amount of unpaid principal balance of impaired financing receivables for which there is no related allowance for credit losses.

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Amount of average investment of impaired financing receivables for which there is a related allowance for credit losses.

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Amount of interest income, recognized on accrual basis, on financing receivables, for which there is a related allowance for credit losses and are recognized as impaired.

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Amount of interest income on financing receivables, for which there is a related allowance for credit losses, recognized on a cash-basis method of accounting that the financing receivables were impaired.

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Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

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