INVESTMENT OPERATIONS - Schedule of Amortized Cost and Fair Value of Investments Classified as Held-to-Maturity (Details) - Successor - USD ($)	11 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Investment [Line Items]
Fair Value	$ 515,000,000	$ 2,733,340,000	$ 515,000,000
Total OTTI Recognized in OCI	0	0
Fixed maturities
Investment [Line Items]
Amortized Cost	593,314,000	2,770,177,000	593,314,000
Gross Unrecognized Holding Gains	0	30,385,000	0
Gross Unrecognized Holding Losses	(78,314,000)	(67,222,000)	(78,314,000)
Fair Value	515,000,000	2,733,340,000	515,000,000
Total OTTI Recognized in OCI		0	0
Fixed maturities | Red Mountain
Investment [Line Items]
Amortized Cost	593,314,000	654,177,000	593,314,000
Gross Unrecognized Holding Gains	0	0	0
Gross Unrecognized Holding Losses	(78,314,000)	(67,222,000)	(78,314,000)
Fair Value	$ 515,000,000	586,955,000	515,000,000
Total OTTI Recognized in OCI		0	$ 0
Fixed maturities | Steel City
Investment [Line Items]
Amortized Cost		2,116,000,000
Gross Unrecognized Holding Gains		30,385,000
Gross Unrecognized Holding Losses		0
Fair Value		2,146,385,000
Total OTTI Recognized in OCI		$ 0