Financing Receivable, Collateral Dependent

No definition available.

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Namespace Prefix:	ewbc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7)(2))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121599878&loc=SL82895884-210446

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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.

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableImpairedLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953550-111524

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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- Details

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- Details

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- Details

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- Details

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Loans Receivable and Allowance for Credit Losses (Impaired Loans) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Impaired loans disclosures
Allowance for loan losses			$ 632,071		$ 358,287
Commercial and industrial (“C&I”)
Impaired loans disclosures
Allowance for loan losses			756
HELOCs
Impaired loans disclosures
Allowance for loan losses			76
Commercial lending
Impaired loans disclosures
Collateral dependent loan			88,100
Commercial lending \| Commercial and industrial (“C&I”)
Impaired loans disclosures
Allowance for loan losses	$ 205,503	$ 205,503	380,723	$ 362,629	238,376	$ 189,757	$ 189,117
Commercial lending \| Commercial real estate (“CRE”)
Impaired loans disclosures
Allowance for loan losses	39,811	39,811	176,040	132,819	40,509	39,224	40,666
Commercial lending \| Real estate loan \| Multifamily residential
Impaired loans disclosures
Allowance for loan losses	19,280	19,280	25,058	16,530	22,826	19,169	19,885
Commercial lending \| Construction and land
Impaired loans disclosures
Allowance for loan losses	22,961	22,961	18,551	11,018	19,404	22,349	20,290
Consumer lending
Impaired loans disclosures
Collateral dependent loan			23,800
Consumer lending \| Real estate loan \| Single-family residential
Impaired loans disclosures
Allowance for loan losses	32,763	32,763	25,314	26,822	28,527	35,759	31,340
Consumer lending \| HELOCs
Impaired loans disclosures
Allowance for loan losses	6,177	6,177	3,867	3,881	5,265	7,401	5,774
Consumer lending \| Other consumer
Impaired loans disclosures
Allowance for loan losses	4,130	4,130	$ 2,518	$ 3,304	3,380	$ 4,235	$ 4,250
Non-PCI Loans
Impaired loans disclosures
Unpaid Principal Balance					266,772
Recorded Investment With No Allowance					129,748
Recorded Investment With Allowance					68,369
Total Recorded Investment					198,117
Related Allowance					5,593
Average Recorded Investment	257,108	269,604
Recognized Interest Income	1,444	2,500
Allowance for loan losses					358,287
Non-PCI Loans \| Commercial lending
Impaired loans disclosures
Unpaid Principal Balance					226,918
Recorded Investment With No Allowance					115,116
Recorded Investment With Allowance					44,699
Total Recorded Investment					159,815
Related Allowance					3,033
Average Recorded Investment	217,782	226,892
Recognized Interest Income	1,277	2,186
Non-PCI Loans \| Commercial lending \| Commercial and industrial (“C&I”)
Impaired loans disclosures
Unpaid Principal Balance					174,656
Recorded Investment With No Allowance					73,956
Recorded Investment With Allowance					40,086
Total Recorded Investment					114,042
Related Allowance					2,881
Average Recorded Investment	182,689	189,553
Recognized Interest Income	1,081	1,816
Non-PCI Loans \| Commercial lending \| Commercial real estate (“CRE”)
Impaired loans disclosures
Unpaid Principal Balance					27,601
Recorded Investment With No Allowance					20,098
Recorded Investment With Allowance					1,520
Total Recorded Investment					21,618
Related Allowance					97
Average Recorded Investment	29,241	31,456
Recognized Interest Income	135	249
Non-PCI Loans \| Commercial lending \| Real estate loan \| Multifamily residential
Impaired loans disclosures
Unpaid Principal Balance					4,965
Recorded Investment With No Allowance					1,371
Recorded Investment With Allowance					3,093
Total Recorded Investment					4,464
Related Allowance					55
Average Recorded Investment	5,852	5,883
Recognized Interest Income	61	121
Non-PCI Loans \| Commercial lending \| Construction and land
Impaired loans disclosures
Unpaid Principal Balance					19,696
Recorded Investment With No Allowance					19,691
Recorded Investment With Allowance					0
Total Recorded Investment					19,691
Related Allowance					0
Non-PCI Loans \| Commercial lending \| Total CRE
Impaired loans disclosures
Unpaid Principal Balance					52,262
Recorded Investment With No Allowance					41,160
Recorded Investment With Allowance					4,613
Total Recorded Investment					45,773
Related Allowance					152
Average Recorded Investment	35,093	37,339
Recognized Interest Income	196	370
Non-PCI Loans \| Consumer lending
Impaired loans disclosures
Unpaid Principal Balance					39,854
Recorded Investment With No Allowance					14,632
Recorded Investment With Allowance					23,670
Total Recorded Investment					38,302
Related Allowance					2,560
Average Recorded Investment	39,326	42,712
Recognized Interest Income	167	314
Non-PCI Loans \| Consumer lending \| Real estate loan \| Single-family residential
Impaired loans disclosures
Unpaid Principal Balance					23,626
Recorded Investment With No Allowance					8,507
Recorded Investment With Allowance					13,704
Total Recorded Investment					22,211
Related Allowance					35
Average Recorded Investment	23,247	24,865
Recognized Interest Income	129	258
Non-PCI Loans \| Consumer lending \| HELOCs
Impaired loans disclosures
Unpaid Principal Balance					13,711
Recorded Investment With No Allowance					6,125
Recorded Investment With Allowance					7,449
Total Recorded Investment					13,574
Related Allowance					8
Average Recorded Investment	13,564	15,321
Recognized Interest Income	38	56
Non-PCI Loans \| Consumer lending \| Total residential mortgage
Impaired loans disclosures
Unpaid Principal Balance					37,337
Recorded Investment With No Allowance					14,632
Recorded Investment With Allowance					21,153
Total Recorded Investment					35,785
Related Allowance					43
Average Recorded Investment	36,811	40,186
Recognized Interest Income	167	314
Non-PCI Loans \| Consumer lending \| Other consumer
Impaired loans disclosures
Unpaid Principal Balance					2,517
Recorded Investment With No Allowance					0
Recorded Investment With Allowance					2,517
Total Recorded Investment					2,517
Related Allowance					$ 2,517
Average Recorded Investment	2,515	2,526
Recognized Interest Income	$ 0	$ 0