FAIR VALUE OF FINANCIAL INSTRUMENTS - Determination of Fair Values Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) primary_source	Dec. 31, 2016 USD ($) quote	Dec. 31, 2016 USD ($) input_method	Dec. 31, 2015 USD ($)
Determination of fair values
Number of primary sources of information used for determining fair value | primary_source				1
Total number of primary sources of information available for determining fair value				3		3
Minimum percentage of the Company's fixed maturity securities priced by third party pricing services		91.00%
Number of independent non-binding broker quotes obtained per security | quote					1
Other asset-backed securities | Level 3
Determination of fair values
Financial instruments that are valued using broker quotes	$ 93,900	$ 93,900	$ 93,900	$ 93,900	$ 93,900	$ 93,900
Embedded derivative - GLWB
Determination of fair values
Discount rate curve, base rate	LIBOR
Embedded derivative - GLWB | Minimum
Determination of fair values
Mortality (as a percent)		91.10%
Embedded derivative - GLWB | Maximum
Determination of fair values
Mortality (as a percent)		106.60%
Embedded derivative—FIA
Determination of fair values
Discount rate curve, base rate	LIBOR
Embedded derivative—FIA | Level 3 | Annuity account | Actuarial cash flow model | Minimum
Determination of fair values
Mortality (as a percent)		46.00%
Embedded derivative—FIA | Level 3 | Annuity account | Actuarial cash flow model | Maximum
Determination of fair values
Mortality (as a percent)		113.00%
Embedded derivative—IUL | Annuity account
Determination of fair values
Discount rate curve, base rate	LIBOR
Embedded derivative—IUL | Level 3 | Actuarial cash flow model | Minimum
Determination of fair values
Mortality (as a percent)		38.00%
Embedded derivative—IUL | Level 3 | Actuarial cash flow model | Maximum
Determination of fair values
Mortality (as a percent)		153.00%
Successor
Determination of fair values
Transfers from Level 1 to Level 2	$ 100	$ 100	100	100	100	100
Percentage of derivatives excluding embedded derivatives that were priced using exchange prices or independent broker quotations		100.00%
Fair value, liabilities	748,821	$ 748,821	748,821	748,821	748,821	748,821	$ 629,555
Successor | Level 3
Determination of fair values
Financial instruments that are valued using broker quotes	128,200	128,200	128,200	128,200	128,200	128,200	200,500
Financial instruments with book value approximating fair value	65,900	65,900	65,900	65,900	65,900	65,900	66,700
Successor | Other asset-backed securities | Level 2
Determination of fair values
Fair value, assets	4,900,000	4,900,000	4,900,000	4,900,000	4,900,000	4,900,000
Successor | Other asset-backed securities | Level 3
Determination of fair values
Fair value, assets	647,200	$ 647,200	647,200	647,200	647,200	647,200
Successor | Other asset-backed securities
Determination of fair values
Percentage of underlying collateral of student-loan backed auction rate securities guaranteed by the Federal Family Education Loan Program (at least)		97.00%
Successor | Other asset-backed securities | Level 3
Determination of fair values
Fair value, assets	553,308	$ 553,308	553,308	553,308	553,308	553,308
Financial instruments that are valued using broker quotes							152,900
Successor | Other asset-backed securities | Level 3 | Available-for-sale securities
Determination of fair values
Fair value, assets	562,600	$ 562,600	562,600	562,600	562,600	562,600
Percentage of underlying collateral of student-loan backed auction rate securities guaranteed by the Federal Family Education Loan Program (at least)		97.00%
Successor | Other asset-backed securities | Level 3 | Trading securities
Determination of fair values
Fair value, assets	84,600	$ 84,600	84,600	84,600	84,600	84,600
Successor | Corporate securities | Level 3
Determination of fair values
Fair value, assets	638,279	638,279	638,279	638,279	638,279	638,279
Financial instruments that are valued using broker quotes	31,300	31,300	31,300	31,300	31,300	31,300	44,500
Successor | Corporate Bonds, U.S. Government-Related Securities, and Other Government Related Securities | Level 2
Determination of fair values
Fair value, assets	30,900,000	30,900,000	30,900,000	30,900,000	30,900,000	30,900,000
Successor | Corporate Bonds, U.S. Government-Related Securities, and Other Government Related Securities | Level 3
Determination of fair values
Fair value, assets	669,500	669,500	669,500	669,500	669,500	669,500
Successor | Embedded derivative - GLWB
Determination of fair values
Fair value, liabilities	2,400,000	2,400,000	2,400,000	2,400,000	2,400,000	2,400,000
Unrealized gain (loss) of securities			147,300
Successor | Embedded derivative - GLWB | Level 3
Determination of fair values
Fair value, liabilities	115,370	$ 115,370	115,370	115,370	115,370	115,370
Successor | Embedded derivative - GLWB | Level 3 | Actuarial cash flow model | Minimum
Determination of fair values
Mortality (as a percent)		91.10%
Successor | Embedded derivative - GLWB | Level 3 | Actuarial cash flow model | Maximum
Determination of fair values
Mortality (as a percent)		106.60%
Successor | Equity securities | Level 2 and Level 3
Determination of fair values
Fair value, assets	69,000	$ 69,000	69,000	69,000	69,000	69,000
Federal home loan bank stock	65,700	65,700	65,700	65,700	65,700	65,700
Successor | Equity securities | Level 3
Determination of fair values
Financial instruments that are valued using broker quotes	3,100	3,100	3,100	3,100	3,100	3,100	$ 3,100
Successor | Embedded derivative—FIA | Level 3
Determination of fair values
Fair value, liabilities	147,368	147,368	147,368	147,368	147,368	147,368
Successor | Embedded derivative—IUL | Level 3
Determination of fair values
Fair value, liabilities	46,051	$ 46,051	46,051	46,051	46,051	46,051
Successor | Embedded derivative—IUL | Level 3 | Actuarial cash flow model | Minimum
Determination of fair values
Mortality (as a percent)		38.00%
Successor | Embedded derivative—IUL | Level 3 | Actuarial cash flow model | Maximum
Determination of fair values
Mortality (as a percent)		153.00%
Measured at fair value on a recurring basis | Successor | Level 2
Determination of fair values
Fair value, assets	36,110,555	$ 36,110,555	36,110,555	36,110,555	36,110,555	36,110,555
Measured at fair value on a recurring basis | Successor | Level 3
Determination of fair values
Fair value, assets	1,510,043	1,510,043	1,510,043	1,510,043	1,510,043	1,510,043
Annuity account balances	87,616	87,616	87,616	87,616	87,616	87,616
Other liabilities | Successor
Determination of fair values
Transfers from Level 1 to Level 2	120,000	120,000	120,000	120,000	120,000	120,000
Other liabilities | Measured at fair value on a recurring basis | Successor
Determination of fair values
Transfers from Level 1 to Level 2	120,000	120,000	120,000	120,000	120,000	120,000
Other long-term investments | Successor
Determination of fair values
Transfers from Level 1 to Level 2	169,400	169,400	169,400	169,400	169,400	169,400
Other long-term investments | Measured at fair value on a recurring basis | Successor
Determination of fair values
Transfers from Level 1 to Level 2	$ 169,400	$ 169,400	$ 169,400	$ 169,400	$ 169,400	$ 169,400