Document and Entity Information - $ / shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018	Dec. 31, 2017
Entity Registrant Name	SUNTRUST BANKS INC
Entity Central Index Key	0000750556
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		449,285,214
Entity Current Reporting Status	Yes
Common Stock, Par or Stated Value Per Share	$ 1.00		$ 1.00