Leases - Lessor, Lease Receivables and Investment in Operating Leases and their Corresponding Balance Sheet Location (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Leases [Abstract]
Lease receivables	$ 251,507	$ 190,559
Guaranteed residual assets	24,045	15,783
Unguaranteed residual assets	10,463	10,010
Deferred initial direct costs	1,352	1,213
Unearned income	(24,673)	(11,891)
Net investment in direct financing and sales-type leases	262,694	205,674
Investment in operating leases	308,993	282,208
Accumulated depreciation	(95,053)	(77,672)
Deferred initial direct costs	978	1,192
Net investment in operating leases	214,918	205,728
Total lease assets	$ 477,612	$ 411,402

Direct Financing Lease, Deferred Initial Direct Costs

No definition available.

Name:	cubi_DirectFinancingLeaseDeferredInitialDirectCosts
Namespace Prefix:	cubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Net Investment in Direct Financing and Operating Leases

+ References

No definition available.

+ Details

Name:	cubi_NetInvestmentinDirectFinancingandOperatingLeases
Namespace Prefix:	cubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Operating Lease, Deferred Initial Direct Costs

+ References

No definition available.

+ Details

Name:	cubi_OperatingLeaseDeferredInitialDirectCosts
Namespace Prefix:	cubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Operating Lease, Investment in Lease, Gross

+ References

No definition available.

+ Details

Name:	cubi_OperatingLeaseInvestmentinLeaseGross
Namespace Prefix:	cubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Operating Lease, Net Investment in Lease

+ References

No definition available.

+ Details

Name:	cubi_OperatingLeaseNetInvestmentinLease
Namespace Prefix:	cubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of deferred selling profit from direct financing lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479773/842-30-50-6

+ Details

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

- Definition

Present value of lease payments not yet received by lessor and amount expected to be derived from underlying asset, following end of lease term, guaranteed by lessee or other third party unrelated to lessor, from direct financing lease.

+ References

+ Details

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

- Definition

Amount excluding accrued interest, before allowance for credit loss, of net investment in direct financing lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

+ Details

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

- Definition

Amount of residual asset covered by residual value guarantee under direct financing lease. Excludes guarantee considered to be lease payments for lessor.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479773/842-30-50-3

+ Details

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

- Definition

Present value expected to be derived from underlying asset, following end of lease term, not guaranteed by lessee or other third party unrelated to lessor.

+ References

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amount of accumulated depreciation of lessor's underlying asset for which right to use has been conveyed to lessee under operating lease.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 840
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481501/840-20-50-4

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479773/842-30-50-13

Reference 3: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-SubTopic 20
-Topic 840
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481532/840-20-45-3

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-1

+ Details

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