Commitments, Contingencies and Related Party Transactions (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Guarantees
Letters of credit	$ 1,796,647	$ 1,655,897
Other Commitments
Unfunded commitments for investments in AHP and other tax credit investments	160,992
Accrued Expenses and Other Liabilities
Guarantees
Allowance for unfunded credit reserves	12,400	12,700
Other Commitments
Unfunded commitments for investments in AHP and other tax credit investments	161,000	169,200
Standby Letters of Credit
Guarantees
Letters of credit	1,710,000
Commercial Letters Of Credit
Guarantees
Letters of credit	81,900
Loans sold or securitized with recourse \| Single Family Residential and Multi-Family Residential \| Loans Sold or Securitized with Recourse
Guarantees
Carrying value of loans sold or securitized	86,674	113,717
Maximum potential future payments	33,758	38,722
Loans sold or securitized with recourse \| Single Family Residential and Multi-Family Residential \| Loans Sold or Securitized with Recourse \| Accrued Expenses and Other Liabilities
Guarantees
Allowance for unfunded credit reserves	$ 123	$ 214

Reflects the Allowance for Unfunded Loan Commitments and Letters of Credit

No definition available.

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248

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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248

+ Details

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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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

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

+ References

No definition available.

+ Details

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- References

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