Derivative Instruments (Details) - Schedule of derivative instruments designated as hedges of the net investment in a foreign operation (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Derivatives Disclosure [Abstract]
Weighted average of U.S. dollar equivalent of foreign denominated net assets	$ 1,872,407		$ 1,656,083		$ 1,882,904		$ 1,542,979
Derivative gains (losses)	$ 56,777	[1]	$ (27,797)	[1]	$ 18,905	[1]	$ (69,206)	[1]

[1] Derivative gains (losses) from derivative instruments designated as hedges of the net investment in a foreign operation are recorded in the cumulative translation adjustment account within AOCI for each period.