Loans and Allowance for Loan Losses (Allowance for Loan Losses and Related Loan Balance Disaggregated on the Basis of Impairment Methodology) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Impaired loans	$ 10,461	$ 9,370
All other loans	181,077	188,168
Impaired loans	149,597	145,360
All other loans		9,265,622
Allowance for Loan Losses [Member]
Impaired loans	10,461
Allowance for Loan Losses [Member] | Commercial [Member]
Impaired loans	6,862
Allowance for Loan Losses [Member] | Personal Banking [Member]
Impaired loans	3,599
Loans Outstanding [Member]
Impaired loans	149,597
All other loans	9,087,481
Loans Outstanding [Member] | Commercial [Member]
Impaired loans	119,133
All other loans	5,333,578
Loans Outstanding [Member] | Personal Banking [Member]
Impaired loans	30,464
All other loans	3,753,903
Commercial [Member]
Impaired loans		6,127
All other loans	120,401	113,819
Impaired loans		118,532
All other loans		5,365,201
Personal Banking [Member]
Impaired loans		3,243
All other loans	60,676	74,349
Impaired loans		26,828
All other loans		$ 3,900,421