Document and Entity Information - USD ($) $ / shares in Units, $ in Billions	12 Months Ended
	Dec. 31, 2017	Feb. 16, 2018	Jun. 30, 2017	Dec. 31, 2016
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-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		468,300,176
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Common Stock, Par or Stated Value Per Share	$ 1.00			$ 1.00
Entity Public Float			$ 26.8