Basis of Presentation (Detail)	Sep. 30, 2015 State
IBERIABANK
Schedule Of Significant Accounting Policies
Number of states with operations	7
IMC
Schedule Of Significant Accounting Policies
Number of states with operations	10

The number of states the entity operates in as of the balance sheet date.

No definition available.

Name:	us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant