INVESTMENT OPERATIONS - Schedule of Investments' Gross Unrealized Losses and Fair Value of the Company's Investments that are Not Deemed to be Other-than-Temporarily Impaired (Details) - Successor - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Fair Value
Less Than 12 Months	$ 2,753,880	$ 30,237,469
12 Months or More	15,257,802	0
Total	18,011,682	30,237,469
Unrealized Loss
Less Than 12 Months	(134,986)	(2,929,180)
12 Months or More	(994,530)	0
Total	(1,129,516)	(2,929,180)
Residential mortgage-backed securities
Fair Value
Less Than 12 Months	192,301	977,433
12 Months or More	152,965	0
Total	345,266	977,433
Unrealized Loss
Less Than 12 Months	(3,103)	(17,112)
12 Months or More	(6,150)	0
Total	(9,253)	(17,112)
Commercial mortgage-backed securities
Fair Value
Less Than 12 Months	43,965	1,232,495
12 Months or More	194,550	0
Total	238,515	1,232,495
Unrealized Loss
Less Than 12 Months	(283)	(41,852)
12 Months or More	(3,443)	0
Total	(3,726)	(41,852)
Other asset-backed securities
Fair Value
Less Than 12 Months	90,316	633,274
12 Months or More	550,860	0
Total	641,176	633,274
Unrealized Loss
Less Than 12 Months	(1,188)	(18,763)
12 Months or More	(34,867)	0
Total	(36,055)	(18,763)
U.S. government-related securities
Fair Value
Less Than 12 Months	1,283	1,291,476
12 Months or More	57,372	0
Total	58,655	1,291,476
Unrealized Loss
Less Than 12 Months	(5)	(34,532)
12 Months or More	(200)	0
Total	(205)	(34,532)
Other government-related securities
Fair Value
Less Than 12 Months	0	17,740
12 Months or More	0	0
Total	0	17,740
Unrealized Loss
Less Than 12 Months	0	(743)
12 Months or More	0	0
Total	0	(743)
States, municipals, and political subdivisions
Fair Value
Less Than 12 Months	34,112	1,566,752
12 Months or More	718,798	0
Total	752,910	1,566,752
Unrealized Loss
Less Than 12 Months	(274)	(126,814)
12 Months or More	(21,320)	0
Total	(21,594)	(126,814)
Corporate securities
Fair Value
Less Than 12 Months	2,336,766	24,235,121
12 Months or More	13,476,384	0
Total	15,813,150	24,235,121
Unrealized Loss
Less Than 12 Months	(128,908)	(2,681,020)
12 Months or More	(923,016)	0
Total	(1,051,924)	(2,681,020)
Preferred Stock
Fair Value
Less Than 12 Months	0	34,685
12 Months or More	19,271	0
Total	19,271	34,685
Unrealized Loss
Less Than 12 Months	0	(1,867)
12 Months or More	(1,667)	0
Total	(1,667)	(1,867)
Equity securities
Fair Value
Less Than 12 Months	55,137	248,493
12 Months or More	87,602	0
Total	142,739	248,493
Unrealized Loss
Less Than 12 Months	(1,225)	(6,477)
12 Months or More	(3,867)	0
Total	$ (5,092)	$ (6,477)