Document and Entity Information
Oct. 21, 2020
Entity Information [Line Items]  
Document Type 8-K
Document Period End Date Oct. 21, 2020
Entity Registrant Name Customers Bancorp, Inc.
Entity Incorporation, State or Country Code PA
Entity File Number 001-35542
Entity Tax Identification Number 27-2290659
Entity Address, Address Line One 701 Reading Avenue
Entity Address, City or Town West Reading
Entity Address, State or Province PA
Entity Address, Postal Zip Code 19611
City Area Code 610
Local Phone Number 933-2000
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company false
Entity Central Index Key 0001488813
Amendment Flag false
Voting Common Stock, par value $1.00 per share | New York Stock Exchange  
Entity Information [Line Items]  
Title of 12(b) Security Voting Common Stock, par value $1.00 per share
Trading Symbol CUBI
Security Exchange Name NYSE
Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series C, par value $1.00 per share | New York Stock Exchange  
Entity Information [Line Items]  
Title of 12(b) Security Fixed-to-Floating Rate Non-Cumulative PerpetualPreferred Stock, Series C, par value $1.00 per share
Trading Symbol CUBI/PC
Security Exchange Name NYSE
Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series D, par value $1.00 per share | New York Stock Exchange  
Entity Information [Line Items]  
Title of 12(b) Security Fixed-to-Floating Rate Non-Cumulative PerpetualPreferred Stock, Series D, par value $1.00 per share
Trading Symbol CUBI/PD
Security Exchange Name NYSE
Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series E, par value $1.00 per share | New York Stock Exchange  
Entity Information [Line Items]  
Title of 12(b) Security Fixed-to-Floating Rate Non-Cumulative PerpetualPreferred Stock, Series E, par value $1.00 per share
Trading Symbol CUBI/PE
Security Exchange Name NYSE
Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series F, par value $1.00 per share | New York Stock Exchange  
Entity Information [Line Items]  
Title of 12(b) Security Fixed-to-Floating Rate Non-Cumulative PerpetualPreferred Stock, Series F, par value $1.00 per share
Trading Symbol CUBI/PF
Security Exchange Name NYSE
5.375% Subordinated Notes due 2034 | New York Stock Exchange  
Entity Information [Line Items]  
Title of 12(b) Security 5.375% Subordinated Notes due 2034
Trading Symbol CUBB
Security Exchange Name NYSE