Statements of Condition (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Available-for-sale securities pledged as collateral that may be repledged	$ 0	$ 3,025
Held-to-maturity securities - pledged as collateral that may be repledged (a)	92	3,456
Allowance for credit losses	500	500
Fair value of held-to-maturity securities	$ 1,035,410	$ 1,528,929
Common Class B [Member]
Common Stock, Class B, putable shares issued	18,691	25,289
Common Stock, Class B, putable par value per share	$ 100	$ 100
Common Stock, Class B, putable shares outstanding	18,691	25,289

Financial Instruments Owned And Pledged As Collateral

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Face amount or stated value per share of common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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The fair value as of the balance sheet date of financial instruments and other positions owned by the entity and pledged to counterparties as collateral, including: (1) mortgages, mortgage-backed and asset backed securities; (2) US government and agency obligations; (3) state and municipal government obligations; (4) other sovereign government debt; (5) corporate obligations; (6) corporate equities; (7) principal investments; (8) derivative contracts; and (9) physical commodities.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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