Derivative Financial Instruments - FGL's Exposure to Credit Loss on Call Options Held (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Fair Value	$ 611	$ 575
Not Designated as Hedging Instrument \| Call options
Derivatives, Fair Value [Line Items]
Notional Amount	18,515	15,909
Fair Value	580	548
Collateral	582	491
Maximum amount of loss due to credit risk	40	58
Not Designated as Hedging Instrument \| Call options \| Merrill Lynch
Derivatives, Fair Value [Line Items]
Notional Amount	2,180	1,932
Fair Value	67	75
Collateral	27	32
Maximum amount of loss due to credit risk	40	43
Not Designated as Hedging Instrument \| Call options \| Morgan Stanley
Derivatives, Fair Value [Line Items]
Notional Amount	2,051	1,503
Fair Value	61	40
Collateral	67	41
Maximum amount of loss due to credit risk	0	0
Not Designated as Hedging Instrument \| Call options \| Barclay's Bank
Derivatives, Fair Value [Line Items]
Notional Amount	5,508	4,639
Fair Value	154	180
Collateral	165	169
Maximum amount of loss due to credit risk	0	11
Not Designated as Hedging Instrument \| Call options \| Canadian Imperial Bank of Commerce
Derivatives, Fair Value [Line Items]
Notional Amount	2,499	2,276
Fair Value	87	86
Collateral	94	85
Maximum amount of loss due to credit risk	0	1
Not Designated as Hedging Instrument \| Call options \| Wells Fargo
Derivatives, Fair Value [Line Items]
Notional Amount	2,575	2,900
Fair Value	87	106
Collateral	90	105
Maximum amount of loss due to credit risk	0	1
Not Designated as Hedging Instrument \| Call options \| Goldman Sachs
Derivatives, Fair Value [Line Items]
Notional Amount	383	634
Fair Value	11	15
Collateral	13	15
Maximum amount of loss due to credit risk	0	0
Not Designated as Hedging Instrument \| Call options \| Credit Suisse
Derivatives, Fair Value [Line Items]
Notional Amount	2,184	1,373
Fair Value	78	27
Collateral	89	25
Maximum amount of loss due to credit risk	0	2
Not Designated as Hedging Instrument \| Call options \| Truist
Derivatives, Fair Value [Line Items]
Notional Amount	1,135	652
Fair Value	35	19
Collateral	37	19
Maximum amount of loss due to credit risk	$ 0	$ 0

Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets.

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