Represents the cost to execute trading of available-for-sale securities by a third party manager engaged by the entity.

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Debt Securities, Held-To-Maturity, Allowance For Credit Loss To Date

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Represents the number of shares acquired in the equity security investment.

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Represents the percentage ownership in the equity security investment.

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Represents the fair value balance of the investment securities before consolidation of the VIEs.

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Represents the fair value balance of the investment securities before consolidation of the VIEs that is eliminated against VIE liabilities.

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Represents the unpaid principal balance of the investment securities before consolidation of the VIEs.

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Represents the amount of investment securities bearing variable interest rates.

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Represents the percentage of investment securities bearing variable interest rates.

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Number of securities with unrealized losses.

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Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity).

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

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Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value of securitized, pay-through debt securities collateralized by real estate mortgage loans classified as available-for-sale.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Investment Securities - Narrative (Details)	3 Months Ended		12 Months Ended
Investment Securities - Narrative (Details)	Mar. 31, 2023 USD ($) security	Mar. 31, 2022 USD ($)	Dec. 31, 2012 shares	Dec. 31, 2022 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Cost of third party management	$ 200,000	$ 300,000
Number of securities with unrealized losses \| security	11			10
Credit loss allowance	$ 10,240,000			$ 3,182,000
Amortized Cost Basis	642,979,000			676,652,000
SEREF
Debt Securities, Available-for-sale [Line Items]
Number of shares acquired (in shares) \| shares			9,140,000
Equity security, fair value	$ 10,100,000			9,800,000
Ownership percentage	2.00%
Fair value option
Debt Securities, Available-for-sale [Line Items]
Fair value of mortgage backed securities	$ 1,700,000,000
VIE eliminations
Debt Securities, Available-for-sale [Line Items]
Fair value of investment securities before consolidation of VIEs eliminated against VIE liabilities	18,900,000
RMBS
Debt Securities, Available-for-sale [Line Items]
Portion of securities with variable rate	$ 97,700,000
RMBS \| Available-for-sale
Debt Securities, Available-for-sale [Line Items]
Portion of securities with variable rate (as a percent)	88.00%
RMBS \| Fair value option
Debt Securities, Available-for-sale [Line Items]
Portion of securities with variable rate	$ 0
Fair value of investment securities before consolidation of VIEs	427,600,000
Unpaid principal balance of investment securities before consolidation of VIEs	326,300,000
CMBS
Debt Securities, Available-for-sale [Line Items]
Credit loss allowance	154,000			172,000
Amortized Cost Basis	581,525,000			577,681,000
CMBS \| Fair value option
Debt Securities, Available-for-sale [Line Items]
Portion of securities with variable rate	97,200,000
Fair value of investment securities before consolidation of VIEs	1,200,000,000
Unpaid principal balance of investment securities before consolidation of VIEs	2,800,000,000
Infrastructure bonds
Debt Securities, Available-for-sale [Line Items]
Credit loss allowance	10,086,000			3,010,000
Amortized Cost Basis	30,927,000			$ 69,214,000
Infrastructure bonds \| Credit deteriorated \| Infrastructure Portfolio Segment \| Choctaw, Mississippi
Debt Securities, Available-for-sale [Line Items]
Credit loss allowance	7,200,000
Allowance for credit loss to date	10,000,000
Amortized Cost Basis	$ 19,200,000