Reconciliation of Policy and Contract Benefits and Reserves for Future Policy and Contract Benefits (Detail) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2020
Insurance [Abstract]
Policy and Contract Benefits	$ 1,815.9	$ 1,907.7	$ 1,890.4
Reserves for Future Policy and Contract Benefits	43,088.0	48,007.5	48,952.0
Total Policy and Contract Benefits and Reserves for Future Policy and Contract Benefits	44,903.9		50,842.4
Life Reserves for Future Policy and Contract Benefits	8,418.8		8,431.1
Accident and Health Active Life Reserves	13,287.9		12,910.4
Adjustment Related to Unrealized Investment Gains and Losses	104.2		5,386.6
Liability for Unpaid Claims and Claim Adjustment Expense	$ 23,093.0	$ 23,664.7	$ 24,114.3	$ 24,180.2

Accident and Health Active Life Reserves

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- Definition

Life Reserves for Future Policy and Contract Benefits

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Policy and contract benefits represent amounts paid and expected to be paid based on reported losses and estimates of incurred but not reported losses for non-interest sensitive life and accident and health products. For interest sensitive products, benefits are the amounts paid and expected to be paid on insured claims in excess of the policyholders' policy fund balances.

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Unrealized Adjustment to Reserves for Future Policy and Contract Benefits

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The amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before the balance sheet date, whether or not reported to the insurer at that date.

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Amount, before effect of reinsurance, of present value of future benefit to be paid to or on behalf of policyholder and related expense less present value of future net premium receivable under insurance contract.

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The aggregate amount of policy reserves (provided for future obligations including unpaid claims and claims adjustment expenses) and policy benefits (liability for future policy benefits) as of the balance sheet date; grouped amount of all the liabilities associated with the company's insurance policies.

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