Rollforward of Credit Losses Recognized in Earnings Related to Securities (Parenthetical) (Detail) (USD $) In Millions	6 Months Ended
Jun. 30, 2010
Schedule of Available-for-sale Securities [Line Items]
Recognized OTTI on debt securities in which no portion of the OTTI loss remained in AOCI at any time during the period	$ 2

Name:

sti_OtherThanTemporaryImpairmentLossesDebtSecurities

Namespace Prefix:

sti

Data Type:

xbrli:monetaryItemType

Balance Type:

credit

Period Type:

duration