Goodwill and Intangible Assets - Additional Information (Details) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Bank Servicing Fees	$ 43,000,000us-gaap_ServicingFeesNet	$ 54,000,000us-gaap_ServicingFeesNet
Mortgage Servicing Rights, Fair Value [Member]
Bank Servicing Fees	82,000,000	79,000,000
Qualitative and Quantitative Information, Transferor's Continuing Involvement, Principal Amount Outstanding	141,800,000,000		142,100,000,000
Principal Amount Outstanding of Loans Serviced For Third Parties	115,200,000,000		115,500,000,000
Unpaid Principal Balance of Outstanding Underlying MSRs Purchased	6,100,000,000	0
Unpaid Principal Balance of Outstanding Underlying MSRs Transferred	1,200,000,000
Principal Amount Sold on Loans Serviced for Third Parties	$ 215,000,000	$ 289,000,000

Principal Amount Outstanding of Loans Serviced for Third Parties

No definition available.

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- Definition

Principal Amount Sold on Loans Serviced for Third Parties

+ References

No definition available.

+ Details

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Balance Type:	debit
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- Definition

Unpaid Principal Balance of Outstanding Underlying Mortgage Servicing Rights Purchased

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Unpaid Principal Balance of Outstanding Underlying MSRs Transferred

+ References

No definition available.

+ Details

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Namespace Prefix:	sti_
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- Definition

Principal amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=13989330&loc=d3e107314-111719

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

Amount of revenue from servicing real estate mortgages, credit cards, and other financial assets held by others. Includes premiums received in lieu of regular servicing fees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 13

-Article 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.13 (d))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

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Balance Type:	credit
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- Details

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