Shareholders' Equity (Narrative) (Details) $ / shares in Units, $ in Millions		1 Months Ended	12 Months Ended
	Aug. 17, 2006 $ / shares $ / right shares	Dec. 31, 2006 shares	Dec. 31, 2007 USD ($)	Dec. 31, 2015 USD ($) shares	Dec. 24, 2008 shares
Dividends:
Amount of additional dividends the bank could have declared | $				$ 194.3
Amended and Restated Dividend Reinvestment and Stock Purchase Plan [Member]
Reserved Shares:
Reserved shares available for grant					607,500
2006 Rights Agreement [Member]
Shareholder Rights Plan:
Number of rights per outstanding share of common stock	1
Number of securities called by rights	1
Exercise price of shares | $ / shares	$ 100
Days after an acquiring person acquired beneficial ownership causing rights to become exercisable	10 days
Percentage acquistion of company's common stock causing rights to become exercisable	15.00%
Exercise price per right available to company prior to expiration | $ / right	0.01
Exercise price percentage per right in event a party becomes an acquiring person	200.00%
Exercise price percentage per right in event company is acquired	200.00%
Reserved Shares:
Reserved shares available for grant				2,292,840
2006 Stock Repurchase Plan [Member]
Stock Repurchase Program:
Authorized amount (in shares)		400,000
Authorized amount as a percentage of total common stock		3.00%
Cumulative amount of shares purchased				185,400
Shares repurchased, value | $			$ 4.8