INCOME TAXES - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Line Items]
Japan Tax Rate		28.00%	28.00%	28.00%
U.S. federal statutory corporate income tax rate		21.00%	21.00%	21.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax Asset (Liability)	$ (1,400)
Non-life operating loss carryforwards, limitations		only 35% of non-life operating losses can be offset against life insurance taxable income each year
Non-life operating loss carryforwards		$ 56
Unrecognized tax benefit, deductibility highly certain, timing uncertain		0	$ 15
Unrecognized tax benefits, permanent uncertainties		5
Unrecognized tax benefits, interest and penalties expense		1
Unrecognized tax benefits, accrued interest and penalties		0	$ 3
Capital Loss Carryforward
Income Taxes [Line Items]
Tax credit carryforward, amount		0
Foreign Tax Credit
Income Taxes [Line Items]
Tax credit carryforward, amount		31
Tax Year 2030 | Foreign Tax Credit
Income Taxes [Line Items]
Tax credit carryforward, amount		3
Tax Year 2031 | Foreign Tax Credit
Income Taxes [Line Items]
Tax credit carryforward, amount		$ 28