XML 83 R71.htm IDEA: XBRL DOCUMENT
v3.21.1

Disclosures About Fair Value of Financial Instruments - Narrative (Detail) | 3 Months Ended
--- | ---
Mar. 31, 2021
Fair Value Disclosures [Abstract] |
Loans held for sale, average life from purchase to sale | 30 days

X
- Definition Loans Held For Sale Average Life From Purchase To Sale + References No definition available. + Details
Name: | cubi_LoansHeldForSaleAverageLifeFromPurchaseToSale
Namespace Prefix: | cubi_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_FairValueDisclosuresAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration