Loan Servicing - Summary of Residential Mortgage Banking Activities (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Transfers and Servicing [Abstract]
UPB of residential mortgage and home equity loan servicing portfolio	$ 118,424	$ 121,639	$ 122,169
UPB of residential mortgage loans serviced for others, primarily agency conforming fixed rate	89,124	90,325	91,132
Mortgage loans sold with recourse	490	578	702
Maximum recourse exposure from mortgage loans sold with recourse liability	251	282	326
Indemnification, recourse and repurchase reserves	37	40	79
UPB of residential mortgage loans sold	12,423	15,675	14,764
Pre-tax gains recognized on mortgage loans sold and held for sale	153	139	148
Servicing fees recognized from mortgage loans serviced for others	$ 261	$ 268	$ 273
Approximate weighted average servicing fee on the outstanding balance of residential mortgage loans serviced for others	0.28%	0.28%	0.29%
Weighted average interest rate on mortgage loans serviced for others	4.00%	4.03%	4.12%

Represents the total exposure to the Registrant from residential mortgage loans sold with recourse liability.

No definition available.

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- Definition

Difference between the sale price and the carrying value when a financial asset transferred in a securitization or asset-backing financing arrangement is accounted for as a sale.

+ References

No definition available.

+ Details

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- Definition

Represents the reserve recorded for expected losses related to indemnification, recourse and representations & warranties residential mortgage loans sold.

+ References

No definition available.

+ Details

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- Definition

Represents the carrying amount of residential mortgage loans sold with recourse.

+ References

No definition available.

+ Details

Name:	bbt_ResidentialMortgageLoansSoldWithRecourse
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Data Type:	xbrli:monetaryItemType
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- Definition

Represents the weighted average servicing fee earned from servicing residential mortgage loans. The amount is presented as the percentage of fee income divided by the outstanding balances of the residential mortgage loans being serviced.

+ References

No definition available.

+ Details

Name:	bbt_ResidentialMortgageLoansWeightedAverageServicingFeePercentage
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- Definition

Represents the unpaid principal balance of total residential mortgage servicing portfolio. This includes the unpaid principal balances held for investment included on the balance sheet as well as the portion serviced for others representing the balances sold to third-party investors.

+ References

No definition available.

+ Details

Name:	bbt_TotalResidentialMortgageServicingPortfolio
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Definition

Reflects the unpaid principal balances of residential mortgage loans sold to third-party investors during the period.

+ References

No definition available.

+ Details

Name:	bbt_UnpaidPrincipalBalanceOfResidentialmortgageloanssold
Namespace Prefix:	bbt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the unpaid principal balance of residential mortgage loans serviced for others that were previously sold to third-party investors.

+ References

No definition available.

+ Details

Name:	bbt_UnpaidPrincipalBalancesOfResidentialMortgageLoansServicedForOthers
Namespace Prefix:	bbt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the weighted average interest rate on the portfolio of residential mortgage loans serviced for others.

+ References

No definition available.

+ Details

Name:	bbt_WeightedAverageInterestRateServicedForOthers
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Data Type:	num:percentItemType
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Period Type:	instant

- 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 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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- References

No definition available.

+ Details

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