Impaired Loans, Measurement Input

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- Definition

Restricted Stock Amortization

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- Definition

Vesting period of time-based restricted stock, higher limit

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- Definition

Vesting period of time-based restricted stock, lower limit

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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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- Definition

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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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

Percentage of vesting of award under share-based payment arrangement.

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Stock-Based Compensation - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($) shares	Mar. 31, 2020 USD ($)	Dec. 31, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Amortization \| $	$ 6,400	$ 6,500
Unvested restricted shares (shares)	2,189,181		1,608,126
Vesting period of time-based restricted stock, lower limit	three
Vesting period of time-based restricted stock, higher limit	4 years
Discount From Appraisals \| Other real estate and foreclosed assets \| Level 3 \| Fair Value, Measurements, Nonrecurring \| Measurement Input, Discount Rate \| Third party appraisals
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Discount rates	13.00
Discount From Appraisals \| Weighted Average \| Other real estate and foreclosed assets \| Level 3 \| Fair Value, Measurements, Nonrecurring \| Measurement Input, Discount Rate \| Third party appraisals
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Discount rates	0.1300
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted shares (shares)	531,333
Vesting term	3 years
Performance Shares \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	0.00%
Performance Shares, One \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	150.00%
Performance Shares, Two \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	200.00%
PacWest 2017 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (shares)	4,000,000
Number of shares available for grant (shares)	990,570
Unrecognized share based compensation expense \| $	$ 67,200
PacWest 2017 Stock Incentive Plan [Member] \| Time-Based Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted shares (shares)	2,189,181