Borrowings and Subordinated Debentures - Interest Rates and Maturity Dates of FHLB Secured Advances (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Rate	0.04%	1.64%
FHLB secured advances \| Federal Home Loan Bank of San Francisco
Debt Instrument [Line Items]
Balance	$ 10,000	$ 1,318,000
Rate	0.00%	1.66%
More Than Twelve (12) Months but Less Than Eighteen Months (18) [Member] \| Federal Home Loan Bank of San Francisco
Debt Instrument [Line Items]
Balance	$ 5,000	$ 0
More Than Twelve (12) Months but Less Than Eighteen Months (18) [Member] \| FHLB secured advances \| Federal Home Loan Bank of San Francisco
Debt Instrument [Line Items]
Rate	0.00%	0.00%
Maturity Overnight [Member] \| Federal Home Loan Bank of San Francisco
Debt Instrument [Line Items]
Balance	$ 0	$ 1,318,000
Maturity Overnight [Member] \| FHLB secured advances \| Federal Home Loan Bank of San Francisco
Debt Instrument [Line Items]
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.00%
Rate		1.66%
2020 \| Federal Home Loan Bank of San Francisco
Debt Instrument [Line Items]
Balance	$ 5,000	$ 0
2020 \| FHLB secured advances \| Federal Home Loan Bank of San Francisco
Debt Instrument [Line Items]
Short-term Debt, Percentage Bearing Fixed Interest Rate	0.00%	0.00%

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.

No definition available.

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- Definition

The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: 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(19))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate.

+ References

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(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The portion of the carrying amount of short-term borrowings outstanding as of the balance sheet date which accrues interest at a set, unchanging rate.

+ References

No definition available.

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