Earnings Per Share - Additional Information (Detail)	3 Months Ended
Mar. 31, 2015
Earnings Per Share [Abstract]
Percentage of stock dividend declared	10.00%cubi_PercentageOfStockDividendDeclared
Dividend declared date	May 15, 2014
Dividend issued date	Jun. 30, 2014

Date the dividend to be paid was declared, in CCYY-MM-DD format.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

Name:	us-gaap_DividendsPayableDateDeclaredDayMonthAndYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration