DERIVATIVE FINANCIAL INSTRUMENTS - Realized Investment Gains and Losses for the Modco Trading Portfolio that is Included in Realized Investment Gains (Losses) - All Other Investments (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		8 Months Ended	9 Months Ended
	Jan. 31, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2016
Successor
Realized investment gains (losses) - all other investments
Modco trading portfolio		$ 23,995	$ 8,377	$ (133,524)	$ 178,353
Predecessor
Realized investment gains (losses) - all other investments
Modco trading portfolio	$ 73,062