Fair Value of Financial Instruments (Schedule of Effective Portion of the Pre-tax Loss Reclassified from AOCL into Interest Expense on the Condensed Consolidated Statements of Income) (Details) (Interest Expense [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-Tax Loss Reclassified from AOCL into Income (Effective Portion)	$ 33,606	$ 53,758	$ 110,532	$ 160,331