Employee Benefit Plans - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Long Term Incentive Deferred Cash Expense	$ 45	$ 39
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	21
Share Based Compensation Arrangement By Share Based Payment Award Options Available For Additional Grant	17
Fair value of options granted per share		$ 7.37
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	9	8
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year	7
Defined Benefit Plan, Contributions by Employer	1
Contributed To Postretirement Welfare Plan	1
Expected Medicare Subsidy Reimbursement Amount	$ 1
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Long Term Return on Assets	5.25%
Suntrust Retirement Plan [Member] | Pension Plans, Defined Benefit
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Long Term Return on Assets	7.00%
NCF Retirement Plan [Member] | Pension Plans, Defined Benefit
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Long Term Return on Assets	6.50%
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	17
Share Based Compensation Arrangement By Share Based Payment Award Options Available For Additional Grant	6