OPERATING SEGMENTS (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								11 Months Ended	12 Months Ended
	Jan. 31, 2015	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Summarized financial information for the company's segments
Revenues		$ 1,142,040	$ 1,084,388	$ 1,087,067	$ 1,105,297	$ 1,116,987	$ 1,123,646	$ 1,116,401	$ 1,126,913	$ 3,710,669	$ 4,418,792	$ 4,483,947
Pre-tax Adjusted Operating Income (Loss)										484,440	506,892	503,369
Nonoperating Gains (Losses)										(84,598)	(71,835)	90,628
Income before income tax	$ 1,182	86,090	110,850	125,768	112,349	120,415	133,079	168,661	171,842	399,842	435,057	593,997
Income tax (benefit) expense		778,218	(28,308)	(41,500)	(36,935)	(48,148)	(39,785)	(56,541)	(56,494)	(131,543)	671,475	(200,968)
Net income		864,308	82,542	84,268	75,414	72,267	93,294	112,120	115,348	268,299	1,106,532	393,029
Adjusted operating income tax benefit (expense)										(161,153)	646,333	(169,247)
After-tax adjusted operating income										323,287	1,153,225	334,122
Income tax (expense) benefit on adjustments										29,610	25,142	(31,721)
Realized investment (losses) gains:
Derivative financial instruments										29,997	(305,828)	(40,288)
Realized gains (losses) on investments and derivatives										(166,886)	121,428	90,659
Net impairment losses recognized in earnings		(853)	(273)	(2,785)	(7,831)	(10,856)	(3,308)	(967)	(2,617)	(26,993)	(11,742)	(17,748)
Less: related amortization										(8,726)	(39,480)	24,360
Less: VA GLWB economic cost										(70,558)	(84,827)	(82,365)
Net investment income		529,490	$ 507,914	$ 507,771	$ 506,413	496,150	$ 482,729	$ 488,460	$ 475,117	1,632,948	2,051,588	1,942,456
Amortization of deferred policy acquisition costs and value of business acquired										94,056	78,221	149,064
Operating Segment Assets
Investments and other assets		75,973,148				71,501,997					75,973,148	71,501,997
Deferred policy acquisition costs and value of business acquired		2,199,577				2,019,829				1,558,808	2,199,577	2,019,829
Other intangibles		663,572				688,083					663,572	688,083
Goodwill		793,470				793,470					793,470	793,470
Total assets		79,629,767				75,003,379					79,629,767	75,003,379
Life Marketing
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired										107,811	120,753	130,708
Operating Segment Assets
Deferred policy acquisition costs and value of business acquired		1,320,776				1,218,944				1,119,515	1,320,776	1,218,944
Acquisitions
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired										2,035	(6,939)	8,178
Operating Segment Assets
Deferred policy acquisition costs and value of business acquired		74,862				106,532				(178,662)	74,862	106,532
Annuities
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired										(41,071)	(54,471)	(11,031)
Operating Segment Assets
Deferred policy acquisition costs and value of business acquired		772,633				655,618				578,742	772,633	655,618
Stable Value Products
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired										43	2,354	1,176
Operating Segment Assets
Deferred policy acquisition costs and value of business acquired		6,864				5,455				2,357	6,864	5,455
Asset Protection
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired										25,211	16,524	20,033
Operating Segment Assets
Deferred policy acquisition costs and value of business acquired		24,442				33,280				36,856	24,442	33,280
Corporate and Other
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired										27	0	0
Operating Segment Assets
Deferred policy acquisition costs and value of business acquired		0				0				0	0	0
Operating
Summarized financial information for the company's segments
Revenues										3,710,669	4,418,792	4,483,947
Pre-tax Adjusted Operating Income (Loss)										484,440	506,892	503,369
Realized investment (losses) gains:
Net investment income										1,632,948	2,051,588	1,942,456
Amortization of deferred policy acquisition costs and value of business acquired										94,056	78,221	149,064
Operating | Life Marketing
Summarized financial information for the company's segments
Revenues										1,426,090	1,667,118	1,627,848
Pre-tax Adjusted Operating Income (Loss)										57,414	50,778	39,745
Realized investment (losses) gains:
Net investment income										446,439	553,999	525,495
Amortization of deferred policy acquisition costs and value of business acquired										107,811	120,753	130,708
Operating Segment Assets
Investments and other assets		14,914,418				14,050,170					14,914,418	14,050,170
Deferred policy acquisition costs and value of business acquired		1,320,776				1,218,944					1,320,776	1,218,944
Other intangibles		282,361				301,399					282,361	301,399
Goodwill		200,274				200,274					200,274	200,274
Total assets		16,717,829				15,770,787					16,717,829	15,770,787
Operating | Acquisitions
Summarized financial information for the company's segments
Revenues										1,333,430	1,569,083	1,676,017
Pre-tax Adjusted Operating Income (Loss)										194,654	249,749	260,511
Realized investment (losses) gains:
Net investment income										639,422	752,520	764,571
Amortization of deferred policy acquisition costs and value of business acquired										2,035	(6,939)	8,178
Operating Segment Assets
Investments and other assets		19,588,133				19,679,690					19,588,133	19,679,690
Deferred policy acquisition costs and value of business acquired		74,862				106,532					74,862	106,532
Other intangibles		34,548				37,103					34,548	37,103
Goodwill		14,524				14,524					14,524	14,524
Total assets		19,712,067				19,837,849					19,712,067	19,837,849
Operating | Annuities
Summarized financial information for the company's segments
Revenues										443,419	450,306	574,934
Pre-tax Adjusted Operating Income (Loss)										180,231	213,080	213,293
Realized investment (losses) gains:
Net investment income										297,114	321,844	322,608
Amortization of deferred policy acquisition costs and value of business acquired										(41,071)	(54,471)	(11,031)
Operating Segment Assets
Investments and other assets		20,938,409				20,243,333					20,938,409	20,243,333
Deferred policy acquisition costs and value of business acquired		772,634				655,618					772,634	655,618
Other intangibles		170,117				183,449					170,117	183,449
Goodwill		336,677				336,677					336,677	336,677
Total assets		22,217,837				21,419,077					22,217,837	21,419,077
Operating | Stable Value Products
Summarized financial information for the company's segments
Revenues										79,670	190,006	114,580
Pre-tax Adjusted Operating Income (Loss)										56,581	105,261	61,294
Realized investment (losses) gains:
Net investment income										78,459	186,576	107,010
Amortization of deferred policy acquisition costs and value of business acquired										43	2,354	1,176
Operating Segment Assets
Investments and other assets		4,569,639				3,373,646					4,569,639	3,373,646
Deferred policy acquisition costs and value of business acquired		6,864				5,455					6,864	5,455
Other intangibles		8,056				8,722					8,056	8,722
Goodwill		113,813				113,813					113,813	113,813
Total assets		4,698,372				3,501,636					4,698,372	3,501,636
Operating | Asset Protection
Summarized financial information for the company's segments
Revenues										261,693	327,573	269,145
Pre-tax Adjusted Operating Income (Loss)										20,627	24,356	16,487
Realized investment (losses) gains:
Net investment income										17,459	27,325	22,082
Amortization of deferred policy acquisition costs and value of business acquired										25,211	16,524	20,033
Operating Segment Assets
Investments and other assets		918,952				1,013,399					918,952	1,013,399
Deferred policy acquisition costs and value of business acquired		24,441				33,280					24,441	33,280
Other intangibles		133,234				143,865					133,234	143,865
Goodwill		128,182				128,182					128,182	128,182
Total assets		1,204,809				1,318,726					1,204,809	1,318,726
Operating | Corporate and Other
Summarized financial information for the company's segments
Revenues										166,367	214,706	221,423
Pre-tax Adjusted Operating Income (Loss)										(25,067)	(136,332)	(87,961)
Realized investment (losses) gains:
Net investment income										154,055	209,324	200,690
Amortization of deferred policy acquisition costs and value of business acquired										$ 27	0	0
Operating Segment Assets
Investments and other assets		15,043,597				13,141,759					15,043,597	13,141,759
Deferred policy acquisition costs and value of business acquired		0				0					0	0
Other intangibles		35,256				13,545					35,256	13,545
Goodwill		0				0					0	0
Total assets		$ 15,078,853				$ 13,155,304					$ 15,078,853	$ 13,155,304
Predecessor
Summarized financial information for the company's segments
Revenues	340,909
Pre-tax Adjusted Operating Income (Loss)	28,485
Nonoperating Gains (Losses)	(27,303)
Income before income tax	1,182
Income tax (benefit) expense	327
Net income	1,509
Adjusted operating income tax benefit (expense)	(9,228)
After-tax adjusted operating income	19,257
Income tax (expense) benefit on adjustments	9,555
Realized investment (losses) gains:
Derivative financial instruments	(123,274)
Realized gains (losses) on investments and derivatives	81,153
Net impairment losses recognized in earnings	(481)
Less: related amortization	(9,143)
Less: VA GLWB economic cost	(6,156)
Net investment income	175,180
Amortization of deferred policy acquisition costs and value of business acquired	4,072
Predecessor | Life Marketing
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired	4,813
Predecessor | Acquisitions
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired	5,033
Predecessor | Annuities
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired	(7,706)
Predecessor | Stable Value Products
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired	25
Predecessor | Asset Protection
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired	1,820
Predecessor | Corporate and Other
Realized investment (losses) gains:
Amortization of deferred policy acquisition costs and value of business acquired	87
Predecessor | Operating
Summarized financial information for the company's segments
Revenues	340,909
Pre-tax Adjusted Operating Income (Loss)	28,485
Realized investment (losses) gains:
Net investment income	175,180
Amortization of deferred policy acquisition costs and value of business acquired	4,072
Predecessor | Operating | Life Marketing
Summarized financial information for the company's segments
Revenues	145,595
Pre-tax Adjusted Operating Income (Loss)	(1,618)
Realized investment (losses) gains:
Net investment income	47,460
Amortization of deferred policy acquisition costs and value of business acquired	4,813
Predecessor | Operating | Acquisitions
Summarized financial information for the company's segments
Revenues	139,761
Pre-tax Adjusted Operating Income (Loss)	20,134
Realized investment (losses) gains:
Net investment income	71,088
Amortization of deferred policy acquisition costs and value of business acquired	5,033
Predecessor | Operating | Annuities
Summarized financial information for the company's segments
Revenues	7,884
Pre-tax Adjusted Operating Income (Loss)	13,164
Realized investment (losses) gains:
Net investment income	37,189
Amortization of deferred policy acquisition costs and value of business acquired	(7,706)
Predecessor | Operating | Stable Value Products
Summarized financial information for the company's segments
Revenues	8,181
Pre-tax Adjusted Operating Income (Loss)	4,529
Realized investment (losses) gains:
Net investment income	6,888
Amortization of deferred policy acquisition costs and value of business acquired	25
Predecessor | Operating | Asset Protection
Summarized financial information for the company's segments
Revenues	21,953
Pre-tax Adjusted Operating Income (Loss)	2,420
Realized investment (losses) gains:
Net investment income	1,878
Amortization of deferred policy acquisition costs and value of business acquired	1,820
Predecessor | Operating | Corporate and Other
Summarized financial information for the company's segments
Revenues	17,535
Pre-tax Adjusted Operating Income (Loss)	(10,144)
Realized investment (losses) gains:
Net investment income	10,677
Amortization of deferred policy acquisition costs and value of business acquired	$ 87