Long-Term Debt - Schedule of Long Term Debt, Interest Rates and Maturity Dates (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	$ 42,133	$ 41,339
Truist Financial Corporation | Senior notes | Fixed rate
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	15,341	14,431
Truist Financial Corporation | Senior notes | Floating rate
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	899	1,749
Truist Financial Corporation | Subordinated notes | Fixed rate
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	1,296	1,227
Truist Financial Corporation | Capital Note
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	613	611
Truist Financial Corporation | Structured Finance
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	110	112
Truist Bank | Senior notes | Fixed rate
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	12,590	11,560
Truist Bank | Senior notes | Floating rate
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	1,752	1,554
Truist Bank | Subordinated notes | Fixed rate
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	5,176	3,872
Truist Bank | FHLB advances
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	2,634	4,141
Truist Bank | Other long-term debt
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	1,077	1,133
Nonbank | Other long-term debt
Debt Instruments [Line Items]
Long-term Debt, Carrying Amount	$ 645	$ 949