Loans And Allowance For Loan Losses (Credit Quality Of Commercial Loan Portfolio) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Total	$ 5,374,963	$ 5,483,733
Business [Member]
Total	2,808,265	2,957,043
Real Estate - Construction And Land [Member]
Total	386,598	460,853
Real Estate - Business [Member]
Total	2,180,100	2,065,837
Pass [Member]
Total	4,968,667	5,006,500
Pass [Member] | Business [Member]
Total	2,669,868	2,801,328
Pass [Member] | Real Estate - Construction And Land [Member]
Total	304,408	327,167
Pass [Member] | Real Estate - Business [Member]
Total	1,994,391	1,878,005
Special Mention [Member]
Total	94,865	174,014
Special Mention [Member] | Business [Member]
Total	37,460	67,142
Special Mention [Member] | Real Estate - Construction And Land [Member]
Total	4,722	29,345
Special Mention [Member] | Real Estate - Business [Member]
Total	52,683	77,527
Substandard [Member]
Total	243,561	225,292
Substandard [Member] | Business [Member]
Total	75,213	79,640
Substandard [Member] | Real Estate - Construction And Land [Member]
Total	54,696	51,589
Substandard [Member] | Real Estate - Business [Member]
Total	113,652	94,063
Non-Accrual [Member]
Total	67,870	77,927
Non-Accrual [Member] | Business [Member]
Total	25,724	8,933
Non-Accrual [Member] | Real Estate - Construction And Land [Member]
Total	22,772	52,752
Non-Accrual [Member] | Real Estate - Business [Member]
Total	$ 19,374	$ 16,242