Loans And Allowance For Loan Losses (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Loans And Allowance For Loan Losses [Abstract]
Loans pledged at the Federal Home Loan Bank as collateral for borrowings and letters of credit obtained to secure public deposits	$ 3,700,000,000		$ 3,700,000,000
Loans Pledged to the Federal Reserve Bank as collateral for discount window borrowings	1,600,000,000		1,600,000,000
Troubled Debt Restructured Loans	61,500,000		61,500,000
Accruing Restructured Loans	46,669,000		46,669,000		$ 38,739,000
Restructured Loans NonAccrual	14,800,000		14,800,000
Restructured commercial loans performing under their modified terms	30,300,000		30,300,000
Aggregate restructured credit card loans held	7,700,000		7,700,000
Restructured Loans Due to Bankruptcy Proceeding	8,300,000		$ 8,300,000
Period after which loans are deemed in default (in days)			90 days
Effect on Interest Income Resulting From Modification to Credit Card Loans			$ (970,000)
Commitments to lend additional funds to customers with restructured loans	11,600,000		11,600,000
Fair Value of Personal Real Estate Loans Held for Sale	7,100,000		7,100,000
Unpaid Principal Balance on Personal Real Estate Loans Held for Sale	6,800,000		6,800,000
Student Loans Held for Sale, Lower of Cost or Fair Value	5,300,000		5,300,000
Auto loans designated as held for sale		$ 50,400,000	50,360,000	$ 0
Percentage of Held-For-Sale Loans to Total Auto Loan Portfolio		5.00%
Cost of Auto Loans Sold	21,800,000
Gain (Loss) on Sales of Loans, Net			114,000
Auto loans held for sale	20,800,000		20,800,000
Non-accrual HFS loans	0		0
Loans HFS 90 Days Past Due and Still Accruing	22,000		22,000
Foreclosed real estate	1,600,000		1,600,000		2,800,000
Personal property acquired in repossession	$ 2,800,000		$ 2,800,000		$ 3,300,000