Other Borrowings - Textual (Details) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances [Line Items]
Average balance during the period	$ 989,000	$ 1,849,000
Maximum month-end balance during the period	$ 0	$ 25,000,000
Weighted average rate during the period	0.41%	3.29%
Credit facility with the FHLB	$ 898,500,000
FHLB advances outstanding	0	$ 0
Maximum federal funds purchases	140,000,000.0
Federal funds purchased	0	0
Federal Reserve Bank Advances
Federal Home Loan Bank, Advances [Line Items]
Credit facility with the Federal Reserve Bank of San Francisco	74,000,000.0
Borrowings outstanding	$ 0	$ 0
Minimum
Federal Home Loan Bank, Advances [Line Items]
Unencumbered collateral in amount equal to varying percentages	100.00%
Maximum
Federal Home Loan Bank, Advances [Line Items]
Unencumbered collateral in amount equal to varying percentages	160.00%

Advance Line Maintained to Purchase Federal Funds

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- Definition

Federal Home Loan Bank Advances Activity For Period Maximum Outstanding At Any Month End

+ References

No definition available.

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- Definition

Unencumbered collateral in amount equal to varying percentages

+ References

No definition available.

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- Definition

Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

+ References

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- Definition

The calculated average balance outstanding for the year for all Federal Home Loan Bank advances as of the Balance Sheet date.

+ References

+ Details

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- Definition

The calculated weighted average interest rate for Federal Home Loan Bank advances for the period ended as of the Balance Sheet date.

+ References

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- Definition

Amount of advances 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 470
-Section 45
-Paragraph 1
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- Definition

Amount of maximum 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
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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.

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No definition available.

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- Definition

Fair value of the amount outstanding under the credit facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-SubTopic 10
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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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