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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt investment in debt security measured at fair value.

No definition available.

Name:	cwbc_DebtSecuritiesTradingAndEquitySecuritiesFVNIAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix:	cwbc_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in equity securities measured at fair value.

No definition available.

Name:	cwbc_EquitySecuritiesFVNIAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix:	cwbc_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in equity securities measured at fair value.

No definition available.

Name:	cwbc_EquitySecuritiesFVNIAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix:	cwbc_
Data Type:	xbrli:monetaryItemType
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Cost of investment in debt investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

No definition available.

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

- References

No definition available.

Name:	us-gaap_DebtSecuritiesTradingAndEquitySecuritiesFvNiCostAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=123594786&loc=SL75136599-209740

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

Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

No definition available.

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

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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 210.9-03.4)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878