Common And Preferred Stock (Details) (USD $)	12 Months Ended					12 Months Ended					12 Months Ended		12 Months Ended			12 Months Ended							12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Nov. 14, 2008	Dec. 31, 2011 Parent Company [Member]	Dec. 31, 2010 Parent Company [Member]	Dec. 31, 2009 Parent Company [Member]	Dec. 31, 2008 Parent Company [Member]	Dec. 31, 2007 Parent Company [Member]	Dec. 31, 2009 Senior Preferred Shares [Member]	Nov. 14, 2008 Senior Preferred Shares [Member]	Dec. 31, 2009 Warrants [Member]	Dec. 31, 2009 TARP Capital Purchase Program [Member]	Nov. 14, 2008 TARP Capital Purchase Program [Member]	Dec. 31, 2009 TARP Capital Purchase Program [Member] Parent Company [Member]	Dec. 31, 2011 TARP Capital Purchase Program [Member] Senior Preferred Shares [Member]	Dec. 31, 2011 TARP Capital Purchase Program [Member] Warrants [Member]	Dec. 31, 2011 Dividend Reinvestment Plan [Member]	Dec. 31, 2010 Dividend Reinvestment Plan [Member]	Dec. 31, 2009 Dividend Reinvestment Plan [Member]	Jun. 29, 2009 Dividend Reinvestment Plan [Member] Parent Company [Member]	Dec. 31, 2009 At-The-Market Common Equity Offering [Member]	Dec. 31, 2011 Registered Direct Offering [Member]
Common Equity Offering Program [Line Items]
Preferred stock, shares issued	0	0			300,000							300,000
Liquidation preference of preferred stock, per share					$ 1,000							$ 1,000
Number of shares repurchased						49,000	31,000				300,000		2,500,000
Aggregate purchase price of preferred stock			$ 300,000,000					$ 300,000,000			$ 300,000,000
Proceeds from common equity offerings	8,027,000	8,391,000	140,008,000			8,027,000	8,391,000	140,008,000						300,000,000			291,400,000	8,600,000					71,600,000	63,700,000
Estimated life of preferred stock, years															5
Discount on senior preferred shares			(300,000,000)											8,600,000		8,500,000
Number of shares authorized to repurchase										4,500,000
Average price of shares purchased						$ 12.13	$ 12.60
Warrants issued									918,000
Amount of shares each warrant entitles buyer to				1.05				1.1576
Exercise price of warrants								$ 16.42					$ 16.92
Common stock offerings, newly issued common stock	8,213,000	8,430,000	139,754,000																				6,300,000	5,500,000
Common stock, shares authorized	220,974,508	220,974,508																				10,000,000
Maximum voluntary optional cash payments made by shareholders to purchase common shares	100,000
Number of shares reissued from treasury stock																			657,000	649,000	409,000
Proceeds from treasury stock reissued																			$ 8,300,000	$ 8,400,000	$ 4,500,000