Derivative Financial Instruments - Dealer Counterparties and Central Clearing Parties (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Credit Derivatives [Line Items]
Cash collateral received from dealer counterparties	$ 59	$ 20
Cash collateral posted	120	344
Dealer Counterparties [Member]
Credit Derivatives [Line Items]
Cash collateral received from dealer counterparties	61	21
Derivatives in a net gain position secured by that collateral	59	22
Unsecured positions in a net gain with dealer counterparties after collateral postings	1	2
Cash collateral posted	113	172
Derivatives in a net loss position	115	171
Additional collateral that would have been posted had BB&T's credit ratings dropped below investment grade	2	0
Central Clearing Parties [Member]
Credit Derivatives [Line Items]
Cash collateral posted	21	177
Derivatives in a net loss position	7	176
Securities pledged to central clearing parties	$ 120	$ 91