Mortgage Loans (Mortgage Loans Held For Portfolio by Collateral or Guarantee Type) (Details) - Residential Portfolio Segment [Member] - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Residential Mortgage Loans [Line Items]
Total unpaid principal balance	$ 8,648,632	$ 8,283,151
Government Loans [Member]
Residential Mortgage Loans [Line Items]
Total unpaid principal balance	327,448	329,527
Conventional Loans [Member]
Residential Mortgage Loans [Line Items]
Total unpaid principal balance	$ 8,321,184	$ 7,953,624

Amortized cost excluding accrued interest, before allowance for credit loss, fee, and loan in process, of financing receivable. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481598/310-20-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant