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Federal Home Loan Bank and Federal Reserve Bank Borrowings (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Federal Home Loan Bank and Federal Reserve Bank Borrowings [Abstract]
FHLB Borrowing Capacity	$ 2,090,000	$ 1,960,000
FHLB Fixed Rate Advances, Total Amount before valuation adjustment	$ 7,000	953,000
Paycheck Protection Program Liquidity Facility (PPPLF) borrowing rate	0.35%
Federal Reserve Bank, Average balance during the year	$ 1,100	99	$ 14
Federal Reserve Bank borrowing capacity	$ 234,400	$ 209,100

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- Definition

Federal Home Loan Bank, Advances, Maturities Summary by Interest Rate Type, Fixed Rate, Before Valuation Adjustment

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- Definition

Federal Home Loan Bank and Federal Reserve Bank Borrowings [Abstract]

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- Definition

Federal Reserve Bank, Advances, Activity for the year, average balance of agreements outstanding

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- Definition

Federal Reserve Bank, Advances, Maximum Amount Available

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- Definition

Paycheck Protection Program Liquidity Facility (PPPLF) borrowing rate

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- Definition

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

+ References

Reference 1: 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 2: 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

Reference 3: 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

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