Long-Term Debt - FHLB Advances (Details) - Subsidiaries - FHLB Advances Due 2021 to 2047	Dec. 31, 2022 USD ($)
Debt Instrument
Loans and securities serving as FHLB collateral	$ 18,600,000,000
FHLB advances	21,000,000
FHLB maturing in 2023	9,000,000
FHLB maturing in 2024	0
FHLB maturing in 2025	5,000,000
FHLB maturing in 2026	0
FHLB maturing in 2027	0
FHLB maturing thereafter	$ 7,000,000
Weighted-Average
Debt Instrument
Interest rate (as a percent)	3.81%

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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Amount of advance from Federal Home Loan Bank (FHLBank) maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of advance from Federal Home Loan Bank (FHLBank) maturing in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of advance from Federal Home Loan Bank (FHLBank) maturing in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of advance from Federal Home Loan Bank (FHLBank) maturing in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of advance from Federal Home Loan Bank (FHLBank) maturing in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of advance from Federal Home Loan Bank (FHLBank) maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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