INVESTMENT OPERATIONS - Summary of Change in Unrealized Gains (Losses), Net of Income Tax, on Fixed Maturity and Equity Securities, Classified as Available-for-Sale (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		5 Months Ended	6 Months Ended
	Jan. 31, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2015	Jun. 30, 2016
Successor | Fixed maturities
Investment Holdings [Line Items]
Change in unrealized gains (losses), net of income tax		$ 848,995	$ (1,040,143)	$ (1,383,342)	$ 1,481,680
Successor | Equity securities
Investment Holdings [Line Items]
Change in unrealized gains (losses), net of income tax		$ 9,509	$ (9,048)	$ (7,537)	$ 9,439
Predecessor | Fixed maturities
Investment Holdings [Line Items]
Change in unrealized gains (losses), net of income tax	$ 670,229
Predecessor | Equity securities
Investment Holdings [Line Items]
Change in unrealized gains (losses), net of income tax	$ 10,226