Loans And Allowance For Credit Losses (Summary Of Selected Information On TDRs That Includes Recorded Investment On An Accruing And Nonaccruing Basis By Loan Class And Modification Type) (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 18	$ 7	$ 129	$ 180
1-4 family residential		6,185		6,185		$ 5,891
Construction and other consumer real estate		517		517		486
Commercial and industrial		13,368		13,368		13,452
Home equity credit line		2,638		2,638		2,645
Bankcard and other revolving plans		459		459		481
Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		14	3
Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	4
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		16	7
Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	0
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	0
Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		6,185		6,185		5,891
Construction and other consumer real estate		517		517		486
Home equity credit line		2,638		2,638		2,645
Bankcard and other revolving plans		459		459		481
Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	4
Recorded investment resulting from the following modification types		167		167		151
Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Commercial and industrial		66		66		47
Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	4
Recorded investment resulting from the following modification types		21		21		22
Accruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	4
Recorded investment resulting from the following modification types		87		87		69
Accruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5		5		8
Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Recorded investment resulting from the following modification types		18		18		17
Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Recorded investment resulting from the following modification types		23		23		25
Accruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		15		15		14
Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		40		40		42
Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		2		2		1
Accruing [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		57		57		57
Accruing [Member] | Interest Rate Below Market [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		8		8		10
Accruing [Member] | Interest Rate Below Market [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		1		1		0
Accruing [Member] | Interest Rate Below Market [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		3
Accruing [Member] | Interest Rate Below Market [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		3
Accruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Interest Rate Below Market [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5		5		4
Accruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5		5		4
Accruing [Member] | Interest Rate Below Market [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		0		0		0
Accruing [Member] | Interest Rate Below Market [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		1		1		3
Accruing [Member] | Interest Rate Below Market [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
Accruing [Member] | Interest Rate Below Market [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		3
Accruing [Member] | Maturity Or Team Extension [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		36		36		25
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		29		29		19
Accruing [Member] | Maturity Or Team Extension [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		29		29		19
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3		3		4
Accruing [Member] | Maturity Or Team Extension [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3		3		4
Accruing [Member] | Maturity Or Team Extension [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		2		2		1
Accruing [Member] | Maturity Or Team Extension [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		1		1		1
Accruing [Member] | Maturity Or Team Extension [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		1		1		0
Accruing [Member] | Maturity Or Team Extension [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		4		4		2
Accruing [Member] | Principal Forgiveness [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		18		18		17
Accruing [Member] | Principal Forgiveness [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		0		0		0
Accruing [Member] | Principal Forgiveness [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Accruing [Member] | Principal Forgiveness [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Accruing [Member] | Principal Forgiveness [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Principal Forgiveness [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Principal Forgiveness [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Principal Forgiveness [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		10		10		10
Accruing [Member] | Principal Forgiveness [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		7		7		6
Accruing [Member] | Principal Forgiveness [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
Accruing [Member] | Principal Forgiveness [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		17		17		16
Accruing [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Accruing [Member] | Payment Deferral [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		0		0		0
Accruing [Member] | Payment Deferral [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Payment Deferral [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Payment Deferral [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Payment Deferral [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Accruing [Member] | Payment Deferral [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Accruing [Member] | Payment Deferral [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		0		0		0
Accruing [Member] | Payment Deferral [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		0		0		0
Accruing [Member] | Payment Deferral [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
Accruing [Member] | Payment Deferral [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	12		12		12
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	[1]	0		0		0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	8		8		8
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	8		8		8
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	0		0		0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	2		2		2
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	2		2		2
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	[1]	0		0		0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	[1]	2		2		2
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	[1]	0		0		0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	2		2		2
Accruing [Member] | Multiple Modification Types [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	92		92		86
Accruing [Member] | Multiple Modification Types [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	[2]	36		36		28
Accruing [Member] | Multiple Modification Types [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	11		11		10
Accruing [Member] | Multiple Modification Types [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	47		47		38
Accruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	2		2		4
Accruing [Member] | Multiple Modification Types [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	10		10		10
Accruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	12		12		14
Accruing [Member] | Multiple Modification Types [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	[2]	3		3		3
Accruing [Member] | Multiple Modification Types [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	[2]	29		29		30
Accruing [Member] | Multiple Modification Types [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	[2]	1		1		1
Accruing [Member] | Multiple Modification Types [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	33		33		34
Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		18	3
Recorded investment resulting from the following modification types		298		298		251
Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		14	3
Commercial and industrial		91		91		60
Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	0
Recorded investment resulting from the following modification types		18		18		17
Nonaccruing [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Nonaccruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		16	3
Recorded investment resulting from the following modification types		110		110		78
Nonaccruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		2
Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	0
Recorded investment resulting from the following modification types		8		8		8
Nonaccruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	$ 0
Recorded investment resulting from the following modification types		10		10		10
Nonaccruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		1		1		2
Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		9		9		8
Nonaccruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		1		1		2
Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		11		11		12
Nonaccruing [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		131		131		100
Nonaccruing [Member] | Interest Rate Below Market [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		15		15		13
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		4		4		1
Nonaccruing [Member] | Interest Rate Below Market [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5		5		1
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		2
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		2
Nonaccruing [Member] | Interest Rate Below Market [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		0		0		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		0		0		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		7		7		3
Nonaccruing [Member] | Maturity Or Team Extension [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		41		41		28
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		0		0		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		1
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3		3		2
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		0		0		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		1		1		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5		5		3
Nonaccruing [Member] | Principal Forgiveness [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		35		35		20
Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		14		14		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		14		14		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		1		1		1
Nonaccruing [Member] | Principal Forgiveness [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		2		2		2
Nonaccruing [Member] | Principal Forgiveness [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3		3		3
Nonaccruing [Member] | Principal Forgiveness [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		17		17		3
Nonaccruing [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		4		4		7
Nonaccruing [Member] | Payment Deferral [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		1		1		1
Nonaccruing [Member] | Payment Deferral [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		3
Nonaccruing [Member] | Payment Deferral [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		4
Nonaccruing [Member] | Payment Deferral [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		1		1		2
Nonaccruing [Member] | Payment Deferral [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		2
Nonaccruing [Member] | Payment Deferral [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3		3		6
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	72		72		51
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	[1]	53		53		33
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	2		2		1
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	55		55		34
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	2		2		2
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	2		2		2
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	4		4		4
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	[1]	0		0		0
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	[1]	1		1		1
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	[1]	0		0		0
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	1		1		1
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	60		60		39
Nonaccruing [Member] | Multiple Modification Types [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	131		131		132
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	[2]	19		19		25
Nonaccruing [Member] | Multiple Modification Types [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	12		12		12
Nonaccruing [Member] | Multiple Modification Types [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	31		31		37
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	0		0		0
Nonaccruing [Member] | Multiple Modification Types [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	3		3		3
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	3		3		3
Nonaccruing [Member] | Multiple Modification Types [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	[2]	0		0		1
Nonaccruing [Member] | Multiple Modification Types [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	[2]	5		5		5
Nonaccruing [Member] | Multiple Modification Types [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	[2]	0		0		0
Nonaccruing [Member] | Multiple Modification Types [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	5		5		6
Nonaccruing [Member] | Multiple Modification Types [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	$ 39		$ 39		$ 46

[1] 1 Includes TDRs that resulted from other modification types including, but not limited to, a legal judgment awarded on different terms, a bankruptcy plan confirmed on different terms, a settlement that includes the delivery of collateral in exchange for debt reduction, etc.

[2] 2 Includes TDRs that resulted from a combination of any of the previous modification types.