CONSOLIDATED QUARTERLY RESULTS - UNAUDITED (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended							11 Months Ended	12 Months Ended
	Jan. 31, 2015	Mar. 31, 2015	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2014
Successor
Entity Information [Line Items]
Premiums and policy fees		$ 506,386	$ 857,864	$ 829,835	$ 853,351	$ 848,369	$ 864,806	$ 793,572	$ 828,058	$ 2,992,822	$ 3,389,419
Reinsurance ceded		(146,813)	(349,882)	(325,373)	(340,594)	(314,874)	(364,606)	(312,256)	(351,196)	(1,174,871)	(1,330,723)
Net of reinsurance ceded		359,573	507,982	504,462	512,757	533,495	500,200	481,316	476,862	1,817,951	2,058,696
Net investment income		272,211	464,633	451,818	458,783	448,229	438,894	413,544	408,147	1,532,796	1,823,463
Realized investment gains (losses)		(40,004)	(141,068)	21,376	131,364	111,000	(35,113)	37,140	(97,515)	(135,492)	122,672
Other income		49,181	73,630	76,132	71,938	67,178	72,476	74,671	75,459	271,787	288,878
Total revenues		640,961	905,177	1,053,788	1,174,842	1,159,902	976,457	1,006,671	862,953	3,487,042	4,293,709
Total benefits and expenses		616,425	972,322	959,521	914,262	924,923	867,359	850,550	898,520	3,232,854	3,771,028
Income before income tax		24,536	(67,145)	94,267	260,580	234,979	109,098	156,121	(35,567)	254,188	522,681
Income tax expense		8,116	(15,041)	20,965	87,787	76,362	33,824	42,542	(9,991)	74,491	170,073
Net income		$ 16,420	$ (52,104)	$ 73,302	$ 172,793	$ 158,617	$ 75,274	$ 113,579	$ (25,576)	$ 179,697	$ 352,608
Predecessor
Entity Information [Line Items]
Premiums and policy fees	$ 260,582											$ 3,283,069
Reinsurance ceded	(91,632)											(1,395,743)
Net of reinsurance ceded	168,950											1,887,326
Net investment income	164,605											2,098,013
Realized investment gains (losses)	102,703											184,535
Other income	23,388											294,333
Total revenues	459,646											4,464,207
Total benefits and expenses	326,799											3,725,418
Income before income tax	132,847											738,789
Income tax expense	44,325											246,838
Net income	$ 88,522											$ 491,951