Loans Receivable and Allowance for Credit Losses (Composition of Loans Held-for-Investment-Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Accrued interest receivable	$ 107,400	$ 107,500
Loans receivable pledged to secure borrowings and to provide additional borrowing capacity from the FHLB and the FRBSF	27,672,561	23,263,517
Commercial Lending
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Collateral dependent loans	37,000	97,200
Consumer Lending
LOANS RECEIVABLE AND ALLOWANCE FOR LOAN LOSSES
Collateral dependent loans	$ 14,000	$ 17,300

Financing Receivable, Collateral Dependent

No definition available.

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- Definition

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.

+ References

No definition available.

+ Details

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- Definition

Amount, before allowance for credit loss, of accrued interest on financing receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 3B
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447

+ Details

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- Definition

Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=123577603&loc=d3e5086-111524

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