Long-Term Debt And Notes Payable (Components Of Debt) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Total long-term debt	$ 398,958	$ 398,914
Short-term borrowings	794	1,112
5.50% Notes Due 2013 [Member]
Debt Instrument [Line Items]
Total long-term debt	199,789	199,753
Debt instrument interest rate	5.50%
Debt instrument due date	2013
6.55% Notes Due 2036 [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 199,169	$ 199,161
Debt instrument interest rate	6.55%
Debt instrument due date	2036