Policyholders' Liabilities (Future Policy Benefits) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Liability for Future Policy Benefit, before Reinsurance [Abstract]
Life insurance – domestic	$ 71	$ 74
Individual and group annuities and supplementary contracts	1,087,060	1,021,854
Other contract liabilities	11,845,330	8,347,058
Total future policy benefits	$ 12,932,461	$ 9,368,986

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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Amount of accrued obligation to policyholders that relates to insured events under individual and group annuities and supplementary insurance contracts.

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Amount of accrued obligation to policyholders that relates to insured events under long-term life insurance contracts.

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Amount of accrued obligation to policyholders that relates to insured events under other insurance contracts.

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