XML 115 R88.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Employee Benefit Plans - Narrative (Detail) | 12 Months Ended
--- | ---
Dec. 31, 2018 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2018 USD ($) SERP_retirement_age | Dec. 31, 2018 USD ($) year | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($)
Retirement Benefits [Abstract] |  |  |  |  |  |  |
Employers matching contribution |  |  | 50.00% |  |  |  |
Employees first contribution |  |  | 6.00% |  |  |  |
401(k) profit sharing plan, employers matching contribution amount |  | $ 2,100,000 |  |  |  | $ 1,900,000 | $ 1,600,000
SERP annual retirement benefits period (years) | 15 years |  |  |  |  |  |
SERP retirement age |  |  |  | 65 | 65 |  |
SERP target annual retirement benefit | $ 300,000 | 300,000 | $ 300,000 | $ 300,000 | $ 300,000 |  |
SERP annual rate of return |  |  | 7.00% |  |  |  |
SERP present value of the amount owed | $ 4,300,000 | $ 4,300,000 | $ 4,300,000 | $ 4,300,000 | $ 4,300,000 | $ 4,600,000 |

X
- Definition Supplemental executive retirement plans annual rate of return. + References No definition available. + Details
Name: | cubi_SupplementalExecutiveRetirementPlansAnnualRateOfReturn
Namespace Prefix: | cubi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Supplemental executive retirement plans obligation period. + References No definition available. + Details
Name: | cubi_SupplementalExecutiveRetirementPlansObligationPeriod
Namespace Prefix: | cubi_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Supplemental executive retirement plans retirement age. + References No definition available. + Details
Name: | cubi_SupplementalExecutiveRetirementPlansRetirementAge
Namespace Prefix: | cubi_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Supplemental executive retirement plans target annual retirement benefit. + References No definition available. + Details
Name: | cubi_SupplementalExecutiveRetirementPlansTargetAnnualRetirementBenefit
Namespace Prefix: | cubi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition The carrying amount of the liability as of the balance sheet date to an individual under a deferred compensation arrangement. This amount may be the result of periodic accruals made over the period of active employment, or reflect termination benefits resulting contractual terms or a death benefit. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 710 -SubTopic 10 -Section 30 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20015-108363 + Details
Name: | us-gaap_DeferredCompensationArrangementWithIndividualRecordedLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of cost for defined contribution plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage employer matches of the employee's percentage contribution matched. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration