RELATED PARTY TRANSACTIONS (Details) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($)
Related party transactions [Roll Forward]
Loans outstanding at beginning of period	$ 16,166
New loans	6,141
Changes in directors and executive officers	(70)
Loans outstanding end of period	$ 22,237

Reflects the amount of changes in loans outstanding to related parties from changes in directors and executive officers, that eliminated the related party relationship.

No definition available.

+ Details

Name:	bxs_LoansAndLeasesReceivableRelatedPartiesChangesInDirectorsAndExecutiveOfficers
Namespace Prefix:	bxs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts due from related parties at the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(e))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

Name:	us-gaap_LoansAndLeasesReceivableRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the amount of new advances made to related parties in the form of loan and lease receivables.

+ References

+ Details

Name:	us-gaap_LoansAndLeasesReceivableRelatedPartiesAdditions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

Name:	us-gaap_LoansAndLeasesReceivableRelatedPartiesRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration