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	Mar. 31, 2016	Dec. 31, 2015
Fair Value
Less Than 12 Months	$ 11,715,895	$ 30,237,469
12 Months or More	13,482,787	0
Total	25,198,682	30,237,469
Unrealized Loss
Less Than 12 Months	(1,016,888)	(2,929,180)
12 Months or More	(1,093,311)	0
Total	(2,110,199)	(2,929,180)
Residential mortgage-backed securities
Fair Value
Less Than 12 Months	352,723	977,433
12 Months or More	148,132	0
Total	500,855	977,433
Unrealized Loss
Less Than 12 Months	(6,366)	(17,112)
12 Months or More	(3,666)	0
Total	(10,032)	(17,112)
Commercial mortgage-backed securities
Fair Value
Less Than 12 Months	380,635	1,232,495
12 Months or More	455,075	0
Total	835,710	1,232,495
Unrealized Loss
Less Than 12 Months	(6,994)	(41,852)
12 Months or More	(5,095)	0
Total	(12,089)	(41,852)
Other asset-backed securities
Fair Value
Less Than 12 Months	664,648	633,274
12 Months or More	104,692	0
Total	769,340	633,274
Unrealized Loss
Less Than 12 Months	(22,415)	(18,763)
12 Months or More	(6,988)	0
Total	(29,403)	(18,763)
U.S. government-related securities
Fair Value
Less Than 12 Months	42,995	1,291,476
12 Months or More	150,137	0
Total	193,132	1,291,476
Unrealized Loss
Less Than 12 Months	(106)	(34,532)
12 Months or More	(2,130)	0
Total	(2,236)	(34,532)
Other government-related securities
Fair Value
Less Than 12 Months	8,000	17,740
12 Months or More	6,231	0
Total	14,231	17,740
Unrealized Loss
Less Than 12 Months	(29)	(743)
12 Months or More	(42)	0
Total	(71)	(743)
States, municipals, and political subdivisions
Fair Value
Less Than 12 Months	549,109	1,566,752
12 Months or More	945,325	0
Total	1,494,434	1,566,752
Unrealized Loss
Less Than 12 Months	(27,255)	(126,814)
12 Months or More	(44,014)	0
Total	(71,269)	(126,814)
Corporate securities
Fair Value
Less Than 12 Months	9,482,043	24,235,121
12 Months or More	11,632,533	0
Total	21,114,576	24,235,121
Unrealized Loss
Less Than 12 Months	(946,300)	(2,681,020)
12 Months or More	(1,029,261)	0
Total	(1,975,561)	(2,681,020)
Preferred Stock
Fair Value
Less Than 12 Months	22,800	34,685
12 Months or More	19,512	0
Total	42,312	34,685
Unrealized Loss
Less Than 12 Months	(368)	(1,867)
12 Months or More	(1,427)	0
Total	(1,795)	(1,867)
Equity securities
Fair Value
Less Than 12 Months	212,942	248,493
12 Months or More	21,150	0
Total	234,092	248,493
Unrealized Loss
Less Than 12 Months	(7,055)	(6,477)
12 Months or More	(688)	0
Total	$ (7,743)	$ (6,477)