Nonperforming Assets (Parenthetical) (Detail) (Federal Housing Administration Loan, USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Federal Housing Administration Loan
OREO	$ 124	$ 132

Amounts not included in OREO because they represent receivables on federally insured FHA/VA foreclosures.

No definition available.

Name:	sti_ExcludedAmountsRelatedToForeclosuresOfCertainInsuredLoans
Namespace Prefix:	sti_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant