OFFSETTING OF ASSETS AND LIABILITIES - Offsetting of Derivative Liabilities (Details) - Successor - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Offsetting of Derivative Liabilities:
Gross Amounts of Recognized Liabilities	$ 748,821	$ 629,555
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	748,821	629,555
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	171,384	42,382
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Paid	5,595	1,617
Net Amount	571,842	585,556
Repurchase agreements
Gross Amounts of Recognized Liabilities	797,721	438,185
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	797,721	438,185
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Paid	0	0
Net Amount	797,721	438,185
Total Liabilities
Gross Amounts of Recognized Liabilities	1,546,542	1,067,740
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	1,546,542	1,067,740
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	171,384	42,382
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Paid	5,595	1,617
Net Amount	1,369,563	1,023,741
Derivatives not subject to a master netting arrangement or similar arrangement
Offsetting of Derivative Liabilities:
Gross Amounts of Recognized Liabilities	176,979	43,999
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	176,979	43,999
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	171,384	42,382
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Paid	5,595	1,617
Net Amount	0	0
Free-Standing derivatives
Offsetting of Derivative Liabilities:
Gross Amounts of Recognized Liabilities	176,979	43,999
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	176,979	43,999
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	171,384	42,382
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Paid	5,595	1,617
Net Amount	0	0
Total derivatives, not subject to a master netting arrangement or similar arrangement
Offsetting of Derivative Liabilities:
Gross Amounts of Recognized Liabilities	571,842	585,556
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	571,842	585,556
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Paid	0	0
Net Amount	571,842	585,556
Embedded derivative - Modco reinsurance treaties
Offsetting of Derivative Liabilities:
Gross Amounts of Recognized Liabilities	141,301	178,362
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	141,301	178,362
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Paid	0	0
Net Amount	141,301	178,362
Embedded derivative - GLWB
Offsetting of Derivative Liabilities:
Gross Amounts of Recognized Liabilities	237,122	277,236
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	237,122	277,236
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Paid	0	0
Net Amount	237,122	277,236
Embedded derivative—FIA
Offsetting of Derivative Liabilities:
Gross Amounts of Recognized Liabilities	147,368	100,329
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	147,368	100,329
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Paid	0	0
Net Amount	147,368	100,329
Embedded derivative—IUL
Offsetting of Derivative Liabilities:
Gross Amounts of Recognized Liabilities	46,051	29,629
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	46,051	29,629
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Paid	0	0
Net Amount	$ 46,051	$ 29,629