Derivative Financial Instruments (Notional Value Of Outstanding Cash Flow Hedge Contracts By Year Of Maturity And Net Unrealized (Loss) Gain Included In Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Derivative [Line Items]
Notional value of contracts outstanding	$ 3,015,000	$ 2,160,000
Net unrealized (loss) gain included in accumulated other comprehensive income (loss), net of taxes	(55,474)	30,723
2011 [Member]
Derivative [Line Items]
Notional value of contracts outstanding	225,000	780,000
2012 [Member]
Derivative [Line Items]
Notional value of contracts outstanding	990,000	780,000
2013 [Member]
Derivative [Line Items]
Notional value of contracts outstanding	960,000	600,000
2014 [Member]
Derivative [Line Items]
Notional value of contracts outstanding	600,000
2015 [Member]
Derivative [Line Items]
Notional value of contracts outstanding	$ 240,000