Expected Cash Flows for the Pension Benefit and Other Postretirement Benefit Plans (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Pension Plans, Defined Benefit
Expected Benefit Payments
2013	$ 164	[1],[2]
2014	162	[1],[2]
2015	159	[1],[2]
2016	157	[1],[2]
2017	158	[1],[2]
2018-2022	793	[1],[2]
Pension Plans, Defined Benefit | Plan Participants
Employer Contributions
2013 (expected)	8	[1],[2]
Other Postretirement Benefit Plans, Defined Benefit
Expected Benefit Payments
2013	15	[3]
2014	15	[3]
2015	14	[3]
2016	14	[3]
2017	13	[3]
2018-2022	54	[3]
Other Postretirement Benefit Plans, Defined Benefit | Plan Participants
Employer Contributions
2013 (expected)	1	[3]
Medicare Part D
Expected Benefit Payments
2013	(3)
2014	(1)
2015	(1)
2016	(1)
2017	(1)
2018-2022	(6)
Medicare Part D | Plan Participants
Employer Contributions
2013 (expected)	$ (3)

[1] 2The expected benefit payments for the SERP will be paid directly from SunTrust corporate assets.

[2] 1At this time, SunTrust anticipates contributions to the Retirement Plan will be permitted (but not required) during 2013 based on the funded status and contribution limitations under the ERISA.

[3] 3The 2013 expected contribution for the Other Postretirement Benefits Plans represents the Medicare Part D subsidy only. Note that expected benefits under Other Postretirement Benefits Plans are shown net of participant contributions.