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Significant Accounting Policies Cash Equivalents (Details)	12 Months Ended
	Dec. 31, 2020
Cash and Cash Equivalents [Abstract]
Maturity of Federal Funds Sold Considered Cash Equivalents	one day
Maturity of Resell Agreement Considered Cash Equivalents, Minimum	one day
Maturity of Resell Agreements Considered Cash Equivalents, Maximum	30 days

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- Definition

Maturity of Federal Funds Sold Considered Cash Equivalents

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- Definition

Maturity of Resell Agreement Considered Cash Equivalents, Minimum

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No definition available.

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- Definition

Maturity of Resell Agreements Considered Cash Equivalents, Maximum

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No definition available.

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