CERTAIN NONTRADITIONAL LONG-DURATION CONTRACTS - Account Balances and Deferred Sales Inducement Asset (Details) - USD ($) $ in Thousands	1 Months Ended	11 Months Ended	12 Months Ended
	Jan. 31, 2015	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2014
Successor
Activity in the Company's deferred sales inducement asset
Deferred asset, beginning of period		$ 0	$ 11,756
Amounts deferred		14,557	16,212
Amortization		(2,801)	(5,471)
Deferred asset, end of period	$ 0	11,756	22,497
Successor | Annuity account
Certain Nontraditional Long-duration Contracts
Account balances of variable annuities with guarantees invested in variable annuity separate accounts		12,660,894	13,157,068
Successor | Equity mutual funds | Annuity account
Certain Nontraditional Long-duration Contracts
Account balances of variable annuities with guarantees invested in variable annuity separate accounts		5,476,366	8,071,204
Successor | Fixed income mutual funds | Annuity account
Certain Nontraditional Long-duration Contracts
Account balances of variable annuities with guarantees invested in variable annuity separate accounts		7,184,528	$ 5,085,864
Predecessor
Activity in the Company's deferred sales inducement asset
Deferred asset, beginning of period	155,150	$ 154,093		$ 146,651
Amounts deferred	82			18,302
Amortization	(1,139)			(9,803)
Deferred asset, end of period	$ 154,093			$ 155,150