Employee Benefit Plans - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Long Term Incentive Deferred Cash Expense	$ 61	$ 30	$ 157	$ 108
Share Based Compensation Arrangement By Share Based Payment Award Options Available For Additional Grant	17		17
Fair value of options granted per share				$ 7.37
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	5	5	19	17
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year			7
Defined Benefit Plan, Contributions by Employer	2	3	4	7
Contributed To Postretirement Welfare Plan	1	1	1	1
Expected Medicare Subsidy Reimbursement Amount	$ 1		$ 1
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Long Term Return on Assets	5.25%		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%		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%		6.50%