Investments in Securities - Unrealized Gain or Loss Position and Components of Carrying Value of Available for Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Weighted average coupon rate	4.34%	3.83%
Principal Amount	$ 245,902	$ 1,248,910
Amortized Cost	251,160	1,280,872
Gross Unrealized Loss	(14,615)	(45)
Gross Unrealized Gain	0	107,018
Fair Value	236,545	1,387,845
Fannie Mae
Debt Securities, Available-for-sale [Line Items]
Principal Amount	110,870	1,063,403
Amortized Cost	113,889	1,088,209
Gross Unrealized Loss	(7,008)	(21)
Gross Unrealized Gain	0	99,138
Fair Value	106,881	1,187,326
Freddie Mac
Debt Securities, Available-for-sale [Line Items]
Principal Amount	134,952	172,550
Amortized Cost	137,187	179,385
Gross Unrealized Loss	(7,602)	(4)
Gross Unrealized Gain	0	7,797
Fair Value	129,585	187,178
Ginnie Mae
Debt Securities, Available-for-sale [Line Items]
Principal Amount	80	12,957
Amortized Cost	84	13,278
Gross Unrealized Loss	(5)	(20)
Gross Unrealized Gain	0	83
Fair Value	$ 79	$ 13,341

Agency Securities, fixed rate securities, weighted average coupon.

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- Definition

Debt Securities, Available-for-sale, Principal Amount

+ References

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- Definition

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (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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