Loans And Allowance For Loan Losses (Credit Quality Of Commercial Loan Portfolio) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	$ 5,627,227	$ 5,374,963
Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	5,311,737	4,968,667
Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	108,454	94,865
Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	159,118	243,561
Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	47,918	67,870
Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	3,098,908	2,808,265
Business [Member] | Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	2,978,076	2,669,868
Business [Member] | Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	56,130	37,460
Business [Member] | Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	50,636	75,213
Business [Member] | Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	14,066	25,724
Real Estate - Construction And Land [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	335,113	386,598
Real Estate - Construction And Land [Member] | Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	276,077	304,408
Real Estate - Construction And Land [Member] | Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	7,388	4,722
Real Estate - Construction And Land [Member] | Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	36,225	54,696
Real Estate - Construction And Land [Member] | Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	15,423	22,772
Real Estate - Business [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	2,193,206	2,180,100
Real Estate - Business [Member] | Pass [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	2,057,584	1,994,391
Real Estate - Business [Member] | Special Mention [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	44,936	52,683
Real Estate - Business [Member] | Substandard [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	72,257	113,652
Real Estate - Business [Member] | Non-Accrual [Member]
Loans And Allowance For Loan Losses [Line Items]
Carrying Amount	$ 18,429	$ 19,374