Derivative Financial Instruments (Contractual And Weighted-Average Interest Rates, Which Include The Effects Of Hedges Related To Financial Instruments) (Details) (Long-Term Debt [Member])	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Long-Term Debt [Member]
Derivative [Line Items]
Contractual Rates	3.93%	3.55%
Rate Including Impact of Hedges	3.23%	3.20%