Shareholders' Equity And Earnings Per Share (Narrative) (Details) (USD $)	0 Months Ended	6 Months Ended			12 Months Ended	6 Months Ended	3 Months Ended	12 Months Ended
	Feb. 15, 2011	Jun. 30, 2011		Jun. 30, 2010	Dec. 31, 2010	Jun. 30, 2011 Equity Component [Member]	Mar. 31, 2010 Common Stock [Member]	Dec. 31, 2010 Common Stock Offering Additional Series [Member]	Jun. 30, 2011 Series A Preferred Stock [Member]	Dec. 31, 2010 Series A Preferred Stock [Member]	Jun. 30, 2010 Series A Preferred Stock [Member]	Jun. 30, 2011 Series B Preferred Stock [Member]	Dec. 31, 2010 Series B Preferred Stock [Member]	Jun. 30, 2010 Series B Preferred Stock [Member]
Common stock, shares issued		$ 34,988,000		$ 31,084,000	$ 34,864,000		$ 6,700,000	$ 3,700,000
Sale of Stock, Price Per Share							$ 33.25	$ 30.00
Net proceeds from issuance of common stock				210,417,000			210,300,000	104,800,000
Tangible equity units sold					4,600,000
Percentage of tangible equity units sold					7.50%
Tangible equity unit public offering price per unit		50.000000			50.00	40.271818
Tangible equity unit, quarterly cash payments in percentage					222,700,000
Percentage of fair value of debt component quarterly cash payments		7.50%
Debt component marurity date		Dec. 15, 2013
Discount rate on debt component		9.50%
Risk-free rate			[1]	2.80%		0.95%
Expected stock price volatility minimum						35.00%
Expected stock price volatility maximum						(45.00%)
Percent of dividend yield plus stock borrow cost						0.85%
Equity term			[1]	6.2		3.02
Junior subordinated amortizing note, initial principal amount		9.728182
Junior subordinated amortizing note, bearing interest		9.50%
Junior subordinated amortizing note, scheduled final installment payment date		Dec. 15, 2013
Quarterly installments on amortizing note	0.989583	(0.9375)
Extended installment period on amortizing note		Dec. 15, 2015
Non-cumulative perpetual convertible preferred stock, issued		50,000
Preferred stock, liquidation value									$ 1,000	$ 1,000	$ 1,000	$ 1,000	$ 1,000	$ 1,000
Liquidation of preference shares, private transactions		50,000,000
Preferred stock, dividend rate, percentage		8.00%
Preferred Stock is convertible into common stock, option of holder at a conversion rate		$ 38.88
Treasury issued under capital purchase program		$ 250,000,000
Cumulative perpetual convertible preferred stock, issued		250,000
Warrant to purchase of shares		1,643,295
Exercise price of common stock		$ 22.82
Warrant termination period		10
Preferred stock, cumulative dividend at a coupon rate		5.00%
Warrants holders common stock purchase price per share		$ 30.50
Warrants outstanding		19,000			19,000
Warrants expiration date		Feb. 01, 2013

[1] No options were granted in the six months ending June 30, 2011.