Sale Of Vision Bank (Details) (USD $)	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Dec. 31, 2009
Sale Of Subsidiary Bank [Line Items]
Deposits	$ 5,089,187,000		$ 5,095,420,000
Allowance for loan losses	107,310,000	120,174,000	143,575,000	117,405,000	120,676,000	116,717,000
Recognized pre-tax gain, net of expenses related to sale	22,000,000
Vision Bank [Member]
Sale Of Subsidiary Bank [Line Items]
Performing loans sold	354,000,000
Deposits	520,000,000
Fixed assets	12,500,000
Other miscellaneous assets and liabilities for purchase price	27,900,000
Performing Loans [Member]
Sale Of Subsidiary Bank [Line Items]
Allowance for loan losses	22,000,000
Non-Performing Loans [Member]
Sale Of Subsidiary Bank [Line Items]
Allowance for loan losses	$ 88,000,000