Benefit Plans - Schedule of Fair Value of Pension Plan Assets by Three Level Fair Value Hierarchy (Details) - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 15,824	$ 14,352
Cash and cash-equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		212	290
U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	5,452	6,424
International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2,378	2,281
Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		7,782	5,357
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		3,216	4,018
Level 1 | Cash and cash-equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		212	290
Level 1 | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	2,744	3,368
Level 1 | International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		260	360
Level 1 | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		12,608	10,334
Level 2 | Cash and cash-equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	0
Level 2 | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	2,708	3,056
Level 2 | International equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2,118	1,921
Level 2 | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 7,782	$ 5,357
Minimum | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	[1]	23.00%
Minimum | International equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		7.00%
Minimum | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		45.00%
Maximum | U.S. equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	[1]	33.00%
Maximum | International equity securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		17.00%
Maximum | Fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage		55.00%

[1] The plan may hold up to 10% of its assets in Truist common stock.