Borrowings (Summary Of Advances Payable To The Federal Home Loan Bank) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Maturity, Rolling Year [Abstract]
FHLB advances maturing within 1 year, Weighted-Average Contractual Coupon Rate (as a percent)	0.38%	1.79%
FHLB advances maturing after 1 but within 2 years, Weighted-Average Contractual Coupon Rate (as a percent)	0.00%	2.53%
FHLB advances maturing after 2 but within 3 years, Weighted-Average Contractual Coupon Rate (as a percent)	2.95%	0.00%
FHLB advances maturing after 3 but within 4 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.59%	2.95%
FHLB advances maturing after 4 but within 5 years, Weighted-Average Contractual Coupon Rate (as a percent)	1.42%	1.59%
FHLB advances maturing after 5 years, Weighted-Average Contractual Coupon Rate (as a percent)	2.66%	2.66%
Federal Home Loan Bank, Advances, Weighted Average Interest Rate (as a percent)	1.36%	1.87%
Aggregate carrying value of assets pledged as collateral	$ 7,387,054	$ 7,318,748
Remaining borrowing capacity	4,689,642	2,937,644
FHLB advances maturing within 1 year, Total Outstanding	25,000	1,690,000
FHLB advances maturing after 1 but within 2 years, Total Outstanding	110	200,000
FHLB advances maturing after 2 but within 3 years, Total Outstanding	215	130
FHLB advances maturing after 3 but within 4 years, Total Outstanding	50,000	229
FHLB advances maturing after 4 but within 5 years, Total Outstanding	50,000	50,000
FHLB advances maturing after 5 years, Total Outstanding	7,839	8,117
FHLB advances	$ 133,164	$ 1,948,476

Amount of advances from the Federal Home Loan Bank (FHLB).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22 (b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13(3)(a))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

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Amount of advances from Federal Home Loan Bank (FHLBank) maturing after the fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of advances from Federal Home Loan Bank (FHLBank) maturing in the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of advances from Federal Home Loan Bank (FHLBank) maturing in the fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of advances from Federal Home Loan Bank (FHLBank) maturing in the fourth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of advances from Federal Home Loan Bank (FHLBank) maturing in the third rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of advances from Federal Home Loan Bank (FHLBank) maturing in the second rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Weighted average interest rate on advances made and reported by Federal Home Loan Bank (FHLBank).

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Weighted average interest rate on advances made and reported by Federal Home Loan Bank (FHLBank) maturing after the fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Weighted average interest rate on advances made and reported by Federal Home Loan Bank (FHLBank) maturing in the next rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Weighted average interest rate on advances made and reported by Federal Home Loan Bank (FHLBank) maturing in the fifth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Weighted average interest rate on advances made and reported by Federal Home Loan Bank (FHLBank) maturing in the fourth rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Weighted average interest rate on advances made and reported by Federal Home Loan Bank maturing in the third rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Weighted average interest rate on advances made and reported by Federal Home Loan Bank (FHLBank) maturing in the second rolling twelve months following the latest balance sheet. For interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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The carrying amount, as of the date of the latest financial statement presented, of loans receivable which are owned but transferred to serve as collateral for the payment of FHLB debt obligations, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729

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