Shareholders' Equity And Earnings Per Share (Aggregate Fair Values Assigned To Each Component Of Tangible Equity Units) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2011
Units issued	4,600	[1]
Unit price	50.000000
Gross proceeds	$ 230,000
Carrying Value of Tangible Equity Units, Issuance Costs, Including Discount	7,353
Carrying Value Of Tangible Equity Units Net Proceeds	222,647
Other Borrowings [Member]
Carrying Value Of Tangible Equity Units Net Proceeds	43,331
Other Borrowings [Member] | Debt Component [Member]
Carrying Value Of Tangible Equity Units Net Proceeds	43,331
Equity Component [Member] | Surplus [Member]
Carrying Value Of Tangible Equity Units Net Proceeds	179,316
Surplus [Member]
Carrying Value Of Tangible Equity Units Net Proceeds	179,316
Equity Component [Member]
Units issued	4,600	[1]
Unit price	40.271818
Gross proceeds	185,250
Carrying Value of Tangible Equity Units, Issuance Costs, Including Discount	5,934
Carrying Value Of Tangible Equity Units Net Proceeds	179,316
Debt Component [Member]
Units issued	4,600	[1]
Unit price	9.728182
Gross proceeds	44,750
Carrying Value of Tangible Equity Units, Issuance Costs, Including Discount	1,419
Carrying Value Of Tangible Equity Units Net Proceeds	$ 43,331

[1] Each TEU consists of two components: 4.6 million units of the equity component and 4.6 million units of the debt component.