SCHEDULE III - SUPPLEMENTARY INSURANCE INFORMATION (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
Supplementary insurance information
Deferred Policy Acquisition Costs and Value of Businesses Acquired		$ 2,199,577				$ 2,019,829				$ 1,558,808	$ 2,199,577	$ 2,019,829
Future Policy Benefits and Claims		30,957,592				30,511,085				29,703,897	30,957,592	30,511,085
Unearned Premiums		875,405				848,495				723,536	875,405	848,495
Stable Value Products, Annuity Contracts and Other Policyholders' Funds		16,886,759				15,309,500				13,921,256	16,886,759	15,309,500
Net Premiums and Policy Fees		516,965	$ 529,968	$ 525,241	$ 544,510	517,089	$ 512,315	$ 521,343	$ 542,468	1,853,072	2,116,684	2,093,215
Net Investment Income										1,632,948	2,051,588	1,942,456
Benefits and Settlement Expenses										2,539,943	2,957,270	2,880,435
Amortization of deferred policy acquisition costs and value of business acquired										94,056	78,221	149,064
Other Operating Expenses										676,828	948,244	860,451
Premiums Written										167,292	176,900	154,450
Life Marketing
Supplementary insurance information
Deferred Policy Acquisition Costs and Value of Businesses Acquired		1,320,776				1,218,944				1,119,515	1,320,776	1,218,944
Future Policy Benefits and Claims		15,438,739				14,595,370				13,869,102	15,438,739	14,595,370
Unearned Premiums		107				119				135	107	119
Stable Value Products, Annuity Contracts and Other Policyholders' Funds		424,204				426,422				371,618	424,204	426,422
Net Premiums and Policy Fees										882,171	1,011,911	972,247
Net Investment Income										446,439	553,999	525,495
Benefits and Settlement Expenses										1,109,840	1,319,138	1,267,844
Amortization of deferred policy acquisition costs and value of business acquired										107,811	120,753	130,708
Other Operating Expenses										165,317	178,792	177,498
Premiums Written										148	111	122
Acquisitions
Supplementary insurance information
Deferred Policy Acquisition Costs and Value of Businesses Acquired		74,862				106,532				(178,662)	74,862	106,532
Future Policy Benefits and Claims		14,323,713				14,693,744				14,508,877	14,323,713	14,693,744
Unearned Premiums		2,423				2,734				3,082	2,423	2,734
Stable Value Products, Annuity Contracts and Other Policyholders' Funds		4,377,020				4,247,081				4,254,579	4,377,020	4,247,081
Net Premiums and Policy Fees										690,741	785,188	832,083
Net Investment Income										639,422	752,520	764,571
Benefits and Settlement Expenses										1,067,482	1,204,084	1,232,141
Amortization of deferred policy acquisition costs and value of business acquired										2,035	(6,939)	8,178
Other Operating Expenses										89,960	110,607	118,056
Premiums Written										32,134	15,964	18,818
Annuities
Supplementary insurance information
Deferred Policy Acquisition Costs and Value of Businesses Acquired		772,633				655,618				578,742	772,633	655,618
Future Policy Benefits and Claims		1,080,629				1,097,973				1,196,131	1,080,629	1,097,973
Unearned Premiums		0				0				0	0	0
Stable Value Products, Annuity Contracts and Other Policyholders' Funds		7,308,354				7,059,060				7,090,171	7,308,354	7,059,060
Net Premiums and Policy Fees										138,146	152,701	146,458
Net Investment Income										297,114	321,844	322,608
Benefits and Settlement Expenses										226,824	216,629	214,100
Amortization of deferred policy acquisition costs and value of business acquired										(41,071)	(54,471)	(11,031)
Other Operating Expenses										125,946	149,181	140,409
Premiums Written										0	0	0
Stable Value Products
Supplementary insurance information
Deferred Policy Acquisition Costs and Value of Businesses Acquired		6,864				5,455				2,357	6,864	5,455
Future Policy Benefits and Claims		0				0				0	0	0
Unearned Premiums		0				0				0	0	0
Stable Value Products, Annuity Contracts and Other Policyholders' Funds		4,698,371				3,501,636				2,131,822	4,698,371	3,501,636
Net Premiums and Policy Fees										0	0	0
Net Investment Income										78,459	186,576	107,010
Benefits and Settlement Expenses										19,348	74,578	41,736
Amortization of deferred policy acquisition costs and value of business acquired										43	2,354	1,176
Other Operating Expenses										2,620	4,407	3,033
Premiums Written										0	0	0
Asset Protection
Supplementary insurance information
Deferred Policy Acquisition Costs and Value of Businesses Acquired		24,442				33,280				36,856	24,442	33,280
Future Policy Benefits and Claims		55,847				60,790				61,291	55,847	60,790
Unearned Premiums		872,600				844,919				719,516	872,600	844,919
Stable Value Products, Annuity Contracts and Other Policyholders' Funds		0				0				0	0	0
Net Premiums and Policy Fees										128,338	154,166	128,687
Net Investment Income										17,459	27,325	22,082
Benefits and Settlement Expenses										101,881	126,459	106,668
Amortization of deferred policy acquisition costs and value of business acquired										25,211	16,524	20,033
Other Operating Expenses										113,974	160,235	125,957
Premiums Written										121,427	148,093	121,821
Corporate and Other
Supplementary insurance information
Deferred Policy Acquisition Costs and Value of Businesses Acquired		0				0				0	0	0
Future Policy Benefits and Claims		58,664				63,208				68,496	58,664	63,208
Unearned Premiums		275				723				803	275	723
Stable Value Products, Annuity Contracts and Other Policyholders' Funds		$ 78,810				$ 75,301				73,066	78,810	75,301
Net Premiums and Policy Fees										13,676	12,718	13,740
Net Investment Income										154,055	209,324	200,690
Benefits and Settlement Expenses										14,568	16,382	17,946
Amortization of deferred policy acquisition costs and value of business acquired										27	0	0
Other Operating Expenses										179,011	345,022	295,498
Premiums Written										$ 13,583	$ 12,732	$ 13,689
Predecessor
Supplementary insurance information
Net Premiums and Policy Fees	$ 171,910
Net Investment Income	175,180
Benefits and Settlement Expenses	267,287
Amortization of deferred policy acquisition costs and value of business acquired	4,072
Other Operating Expenses	68,368
Premiums Written	13,663
Predecessor | Life Marketing
Supplementary insurance information
Net Premiums and Policy Fees	84,926
Net Investment Income	47,460
Benefits and Settlement Expenses	123,179
Amortization of deferred policy acquisition costs and value of business acquired	4,813
Other Operating Expenses	18,705
Premiums Written	12
Predecessor | Acquisitions
Supplementary insurance information
Net Premiums and Policy Fees	62,343
Net Investment Income	71,088
Benefits and Settlement Expenses	101,926
Amortization of deferred policy acquisition costs and value of business acquired	5,033
Other Operating Expenses	9,041
Premiums Written	2,133
Predecessor | Annuities
Supplementary insurance information
Net Premiums and Policy Fees	12,473
Net Investment Income	37,189
Benefits and Settlement Expenses	30,613
Amortization of deferred policy acquisition costs and value of business acquired	(7,706)
Other Operating Expenses	9,926
Premiums Written	0
Predecessor | Stable Value Products
Supplementary insurance information
Net Premiums and Policy Fees	0
Net Investment Income	6,888
Benefits and Settlement Expenses	2,255
Amortization of deferred policy acquisition costs and value of business acquired	25
Other Operating Expenses	79
Premiums Written	0
Predecessor | Asset Protection
Supplementary insurance information
Net Premiums and Policy Fees	10,825
Net Investment Income	1,878
Benefits and Settlement Expenses	7,592
Amortization of deferred policy acquisition costs and value of business acquired	1,820
Other Operating Expenses	10,121
Premiums Written	10,172
Predecessor | Corporate and Other
Supplementary insurance information
Net Premiums and Policy Fees	1,343
Net Investment Income	10,677
Benefits and Settlement Expenses	1,722
Amortization of deferred policy acquisition costs and value of business acquired	87
Other Operating Expenses	20,496
Premiums Written	$ 1,346