Asset Quality (Details 2) (USD $) In Millions	Jun. 30, 2011
Past due loans including current loans
Current	$ 46,415
30 To 59 Days Past Due	261
60 to 89 Days Past Due	204
Greater Than 90 Days	118
Non Accrual (NPL)	842
Total Past Due	1,425
Total Loans	47,840
Commercial, financial and agricultural [Member]
Past due loans including current loans
Current	16,599
30 To 59 Days Past Due	35
60 to 89 Days Past Due	17
Greater Than 90 Days	19
Non Accrual (NPL)	213
Total Past Due	284
Total Loans	16,883
Commercial real estate: Commercial Mortgage [Member]
Past due loans including current loans
Current	7,743
30 To 59 Days Past Due	34
60 to 89 Days Past Due	51
Greater Than 90 Days	11
Non Accrual (NPL)	230
Total Past Due	326
Total Loans	8,069
Construction [Member]
Past due loans including current loans
Current	1,437
30 To 59 Days Past Due	11
60 to 89 Days Past Due	24
Greater Than 90 Days	28
Non Accrual (NPL)	131
Total Past Due	194
Total Loans	1,631
Commercial Real Estate Loans [Member]
Past due loans including current loans
Current	9,180
30 To 59 Days Past Due	45
60 to 89 Days Past Due	75
Greater Than 90 Days	39
Non Accrual (NPL)	361
Total Past Due	520
Total Loans	9,700
Commercial Lease Financing [Member]
Past due loans including current loans
Current	5,983
30 To 59 Days Past Due	20
60 to 89 Days Past Due	40
Greater Than 90 Days	21
Non Accrual (NPL)	41
Total Past Due	122
Total Loans	6,105
Commercial Loans [Member]
Past due loans including current loans
Current	31,762
30 To 59 Days Past Due	100
60 to 89 Days Past Due	132
Greater Than 90 Days	79
Non Accrual (NPL)	615
Total Past Due	926
Total Loans	32,688
Real estate - residential mortgage [Member]
Past due loans including current loans
Current	1,713
30 To 59 Days Past Due	24
60 to 89 Days Past Due	14
Greater Than 90 Days	8
Non Accrual (NPL)	79
Total Past Due	125
Total Loans	1,838
Home Equity Key Community Bank [Member]
Past due loans including current loans
Current	9,216
30 To 59 Days Past Due	66
60 to 89 Days Past Due	32
Greater Than 90 Days	16
Non Accrual (NPL)	101
Total Past Due	215
Total Loans	9,431
Home Equity Other [Member]
Past due loans including current loans
Current	559
30 To 59 Days Past Due	13
60 to 89 Days Past Due	7
Greater Than 90 Days	5
Non Accrual (NPL)	11
Total Past Due	36
Total Loans	595
Home Equity Loans [Member]
Past due loans including current loans
Current	9,775
30 To 59 Days Past Due	79
60 to 89 Days Past Due	39
Greater Than 90 Days	21
Non Accrual (NPL)	112
Total Past Due	251
Total Loans	10,026
Consumer Marine [Member]
Past due loans including current loans
Current	1,898
30 To 59 Days Past Due	42
60 to 89 Days Past Due	14
Greater Than 90 Days	3
Non Accrual (NPL)	32
Total Past Due	91
Total Loans	1,989
Consumer others [Member]
Past due loans including current loans
Current	138
30 To 59 Days Past Due	2
60 to 89 Days Past Due	1
Greater Than 90 Days	0
Non Accrual (NPL)	1
Total Past Due	4
Total Loans	142
Consumer other - Key Community Bank [Member]
Past due loans including current loans
Current	1,129
30 To 59 Days Past Due	14
60 to 89 Days Past Due	4
Greater Than 90 Days	7
Non Accrual (NPL)	3
Total Past Due	28
Total Loans	1,157
Consumer Other [Member]
Past due loans including current loans
Current	2,036
30 To 59 Days Past Due	44
60 to 89 Days Past Due	15
Greater Than 90 Days	3
Non Accrual (NPL)	33
Total Past Due	95
Total Loans	2,131
Consumer Loans [Member]
Past due loans including current loans
Current	14,653
30 To 59 Days Past Due	161
60 to 89 Days Past Due	72
Greater Than 90 Days	39
Non Accrual (NPL)	227
Total Past Due	499
Total Loans	$ 15,152