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Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

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Amount of accumulated unrealized gain on investments in debt securities classified as held-to-maturity.

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Amount before allowance of loans made to policy and contract holders using their life insurance contracts' cash value or separate accounts as collateral. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums over and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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The amount by which the fair value of an investment in debt and equity securities categorized as Available-for-sale is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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INVESTMENT OPERATIONS - Additional Information (Details)	1 Months Ended	11 Months Ended	12 Months Ended
	Jan. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($) subsidiary position	Dec. 31, 2016 USD ($) subsidiary
Variable Interest Entities
Trading securities			$ 2,725,694,000	$ 2,699,591,000
Gross unrealized losses, 12 Months or More			$ 602,685,000	1,196,195,000
Number of positions in unrealized loss position \| position			1,845
Available-for-sale securities, fair value			$ 39,819,928,000	36,570,665,000
Available-for-sale securities, amortized cost			39,783,880,000	38,233,986,000
Held-to-maturity securities, unrecognized holding gain			76,600,000
Held-to-maturity securities, unrecognized holding losses			19,200,000
Non-income producing securities			17,500,000
Policy loans			$ 1,615,615,000	$ 1,650,240,000
Interest rate on collateral loans on life insurance policies			13.64%
Number of wholly owned subsidiaries that were determined to be VIEs \| subsidiary			2
Red Mountain
Variable Interest Entities
Number of wholly owned subsidiaries that were determined to be VIEs \| subsidiary				2
Ownership through an affiliate (as a percent)			100.00%
Risk of loss related to the VIE limited to the entity's investment			$ 10,000
Payments made			$ 0
Steel City
Variable Interest Entities
Ownership through an affiliate (as a percent)			100.00%
Risk of loss related to the VIE limited to the entity's investment			$ 10,000
Payments made			0
Fixed maturities
Variable Interest Entities
Trading securities			2,664,189,000	$ 2,639,860,000
Other-than-temporary impairments		$ 0	0	0
Available-for-sale securities, fair value			38,511,863,000	35,543,477,000
Available-for-sale securities, amortized cost			38,489,362,000	37,192,864,000
Held-to-maturity securities, accumulated unrecognized holding gain			76,586,000	30,385,000
Held-to-maturity securities, accumulated unrecognized holding loss			19,163,000	67,222,000
Fixed maturities \| Predecessor
Variable Interest Entities
Other-than-temporary impairments	$ 0
Equity securities
Variable Interest Entities
Trading securities			5,244,000	7,083,000
Other-than-temporary impairments		$ 0	0	0
Gross unrealized losses, 12 Months or More			7,370,000	6,412,000
Available-for-sale securities, fair value			749,116,000	747,406,000
Available-for-sale securities, amortized cost			735,569,000	761,340,000
Equity securities \| Predecessor
Variable Interest Entities
Other-than-temporary impairments	$ 0
Short-term investments
Variable Interest Entities
Trading securities			56,261,000	52,648,000
Available-for-sale securities, fair value			558,949,000	279,782,000
Available-for-sale securities, amortized cost			558,949,000	279,782,000
Residential mortgage-backed securities
Variable Interest Entities
Trading securities			259,694,000	255,027,000
Gross unrealized losses, 12 Months or More			13,362,000	4,117,000
Available-for-sale securities, fair value			2,327,212,000	1,898,483,000
Available-for-sale securities, amortized cost			2,330,832,000	1,913,413,000
Commercial mortgage-backed securities
Variable Interest Entities
Trading securities			146,804,000	149,683,000
Gross unrealized losses, 12 Months or More			21,594,000	4,013,000
Available-for-sale securities, fair value			1,889,822,000	1,811,470,000
Available-for-sale securities, amortized cost			1,914,998,000	1,850,620,000
Other asset-backed securities
Variable Interest Entities
Trading securities			138,097,000	200,084,000
Gross unrealized losses, 12 Months or More			$ 5,441,000	$ 11,407,000
Percentage of underlying collateral of student-loan backed auction rate securities guaranteed by the Federal Family Education Loan Program (at least)			97.00%	97.00%
Available-for-sale securities, fair value			$ 1,249,549,000	$ 1,211,533,000
Available-for-sale securities, amortized cost			1,234,376,000	1,210,490,000
Other government-related securities
Variable Interest Entities
Trading securities			63,925,000	63,012,000
Gross unrealized losses, 12 Months or More			4,778,000	11,890,000
Available-for-sale securities, fair value			287,282,000	239,921,000
Available-for-sale securities, amortized cost			282,767,000	253,182,000
States, municipals, and political subdivisions
Variable Interest Entities
Trading securities			326,925,000	316,519,000
Gross unrealized losses, 12 Months or More			43,874,000	41,749,000
Available-for-sale securities, fair value			1,741,645,000	1,656,503,000
Available-for-sale securities, amortized cost			1,770,299,000	1,760,837,000
Corporate securities
Variable Interest Entities
Trading securities			1,698,183,000	1,624,589,000
Gross unrealized losses, 12 Months or More			472,394,000	1,114,729,000
Available-for-sale securities, fair value			29,702,010,000	27,371,565,000
Available-for-sale securities, amortized cost			29,606,484,000	$ 28,801,768,000
Below investment grade
Variable Interest Entities
Trading securities			229,000,000
Available-for-sale securities, fair value			1,900,000,000
Available-for-sale securities, amortized cost			1,900,000,000
Securities not publicly traded			$ 311,800,000
Minimum
Variable Interest Entities
Interest rate on standard policy loans			3.00%
Maximum
Variable Interest Entities
Interest rate on standard policy loans			8.00%