Investment Securities (Components Of Investment Securities) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Schedule of Investments [Line Items]
Debt Securities, Trading	$ 67,251,000		$ 62,228,000
Debt Securities, Trading and Available-for-sale	$ 71,325,000		66,348,000
Future Prepayment Rate Assumption Of Investment Portfolio	8.30%	7.70%
Mortgage Credit Investment Fund Limited Partnership	$ 63,000		64,000
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	15,000		15,000
Debt Securities, Trading and Available-for-sale	15,000		15,000
Commercial Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	212,000		236,000
Debt Securities, Trading and Available-for-sale	212,000		236,000
Credit Risk Transfer Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	640,000		633,000
Debt Securities, Trading and Available-for-sale	640,000		633,000
Agency Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading	66,384,000		61,344,000
Debt Securities, Trading and Available-for-sale	70,458,000		65,464,000
Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Available For Sale Securities Par	4,313,000		4,447,000
Debt Securities, Available-for-Sale, Unamortized discount	1,000		1,000
Debt Securities, Available-for-Sale, Unamortized premium	260,000		265,000
Debt Securities, Available-for-sale, Amortized Cost	4,572,000		4,711,000
Debt Securities, Available-for-Sale, Gross Unrealized Losses	499,000		591,000
Debt Securities, Available-for-Sale	4,074,000		4,120,000
Debt Securities, Available-for-Sale, Gross Unrealized Gains	1,000		0
Available-for-sale Securities [Member] \| Agency Securities [Member]
Schedule of Investments [Line Items]
Available For Sale Securities Par	4,313,000		4,447,000
Debt Securities, Available-for-Sale, Unamortized discount	1,000		1,000
Debt Securities, Available-for-Sale, Unamortized premium	260,000		265,000
Debt Securities, Available-for-sale, Amortized Cost	4,572,000		4,711,000
Debt Securities, Available-for-Sale, Gross Unrealized Losses	499,000		591,000
Debt Securities, Available-for-Sale	4,074,000		4,120,000
Debt Securities, Available-for-Sale, Gross Unrealized Gains	1,000		0
Trading Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading Securities, Gross Unrealized Gains	424,000		147,000
Debt Securities, Trading Securities, Gross Unrealized Losses	1,749,000		2,654,000
Trading Securities Par	67,817,000		63,984,000
Debt Securities, Trading Securities, Unamortized discount	399,000		396,000
Debt Securities, Trading Securities, Unamortized Premium	1,158,000		1,147,000
Debt Securities, Trading, Amortized Cost	68,576,000		64,735,000
Trading Securities [Member] \| Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading Securities, Gross Unrealized Gains	0		0
Debt Securities, Trading Securities, Gross Unrealized Losses	2,000		2,000
Trading Securities Par	19,000		19,000
Debt Securities, Trading Securities, Unamortized discount	3,000		3,000
Debt Securities, Trading Securities, Unamortized Premium	1,000		1,000
Debt Securities, Trading, Amortized Cost	17,000		17,000
Trading Securities [Member] \| Commercial Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading Securities, Gross Unrealized Gains	3,000		4,000
Debt Securities, Trading Securities, Gross Unrealized Losses	26,000		32,000
Trading Securities Par	238,000		270,000
Debt Securities, Trading Securities, Unamortized discount	5,000		8,000
Debt Securities, Trading Securities, Unamortized Premium	2,000		2,000
Debt Securities, Trading, Amortized Cost	235,000		264,000
Trading Securities [Member] \| Credit Risk Transfer Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading Securities, Gross Unrealized Gains	45,000		50,000
Debt Securities, Trading Securities, Gross Unrealized Losses	0		0
Trading Securities Par	586,000		576,000
Debt Securities, Trading Securities, Unamortized discount	11,000		11,000
Debt Securities, Trading Securities, Unamortized Premium	20,000		18,000
Debt Securities, Trading, Amortized Cost	595,000		583,000
Trading Securities [Member] \| Agency Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading Securities, Gross Unrealized Gains	376,000		93,000
Debt Securities, Trading Securities, Gross Unrealized Losses	1,721,000		2,620,000
Trading Securities Par	66,974,000		63,119,000
Debt Securities, Trading Securities, Unamortized discount	380,000		374,000
Debt Securities, Trading Securities, Unamortized Premium	1,135,000		1,126,000
Debt Securities, Trading, Amortized Cost	67,729,000		63,871,000
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading and Available-for-sale	15,000		15,000
Commercial Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading and Available-for-sale	212,000		236,000
Credit Risk Transfer Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading and Available-for-sale	640,000		633,000
Credit Risk Transfer Securities [Member] \| Securities Remeasured at Fair Value [Member]
Schedule of Investments [Line Items]
Debt Securities, Trading and Available-for-sale	640,000		633,000
Non-Agency [Member] \| Trading Securities [Member] \| Interest-Only-Strip
Schedule of Investments [Line Items]
Trading Securities Par	$ 93,000		$ 93,000

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Inerest in a Mortgage Credit Investment Fund Limited Partnership

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