ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Reclassifications Out of AOCI (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, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Successor
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Benefits and settlement expenses, net of reinsurance ceded										$ (2,535,388)
Realized investment gains (losses): All other investments										(166,935)
Net impairment losses recognized in earnings										(26,993)
Income before income tax		$ 24,536	$ 109,098	$ 156,121	$ (35,567)					254,188
Tax (expense) or benefit		$ (8,116)	$ (33,824)	$ (42,542)	$ 9,991					(74,491)
Predecessor
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Benefits and settlement expenses, net of reinsurance ceded	$ (266,575)										$ (2,786,463)	$ (2,473,988)
Realized investment gains (losses): All other investments	81,153										205,302	(121,537)
Net impairment losses recognized in earnings	(481)										(7,275)	(22,400)
Income before income tax	132,847					$ 230,443	$ 184,120	$ 172,615	$ 151,611		738,789	422,499
Tax (expense) or benefit	(44,325)					$ (78,917)	$ (62,287)	$ (56,572)	$ (49,062)		(246,838)	(130,897)
Gains and losses on derivative instruments | Amount Reclassified from Accumulated Other Comprehensive Income (Loss) | Successor
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Benefits and settlement expenses, net of reinsurance ceded										(131)
Income before income tax										(131)
Tax (expense) or benefit										45
Net of tax										(86)
Gains and losses on derivative instruments | Amount Reclassified from Accumulated Other Comprehensive Income (Loss) | Predecessor
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Benefits and settlement expenses, net of reinsurance ceded	(36)										(1,777)	(2,349)
Income before income tax	(36)										(1,777)	(2,349)
Tax (expense) or benefit	13										622	822
Net of tax	(23)										(1,155)	(1,527)
Unrealized gains and losses on available-for-sale securities | Amount Reclassified from Accumulated Other Comprehensive Income (Loss) | Successor
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Realized investment gains (losses): All other investments										271
Net impairment losses recognized in earnings										(26,992)
Income before income tax										(26,721)
Tax (expense) or benefit										9,352
Net of tax										$ (17,369)
Unrealized gains and losses on available-for-sale securities | Amount Reclassified from Accumulated Other Comprehensive Income (Loss) | Predecessor
Reclassifications Out of Accumulated Other Comprehensive Income (Loss)
Realized investment gains (losses): All other investments	6,891										75,569	66,437
Net impairment losses recognized in earnings	(481)										(7,275)	(22,447)
Income before income tax	6,410										68,294	43,990
Tax (expense) or benefit	(2,244)										(23,903)	(15,396)
Net of tax	$ 4,166										$ 44,391	$ 28,594