Debt (Interest Rates On Outstanding Borrowings Under Term Loans) (Details) (USD $) In Thousands, unless otherwise specified			12 Months Ended			9 Months Ended			9 Months Ended			9 Months Ended
	Sep. 30, 2012	Dec. 31, 2011	Dec. 31, 2011 U.S. Term Loans Loans Payable	Sep. 30, 2012 U.S. Term Loans Loans Payable	Nov. 14, 2011 U.S. Term Loans Loans Payable	Sep. 30, 2012 U.S. Term Loans Swapped To Fixed Rate January Two Thousand Fourteen BasisPoints		Jan. 17, 2012 U.S. Term Loans Swapped To Fixed Rate January Two Thousand Fourteen	Sep. 30, 2012 U.S. Term Loans Swapped To Fixed Rate March Two Thousand Fourteen BasisPoints		Mar. 19, 2012 U.S. Term Loans Swapped To Fixed Rate March Two Thousand Fourteen	Sep. 30, 2012 U.S. Term Loans Floating Rate	Sep. 30, 2012 U.S. Term Loans Swapped to Fixed Rate Two Thousand Sixteen BasisPoints	Jun. 19, 2012 U.S. Term Loans Swapped to Fixed Rate Two Thousand Sixteen
Debt Instrument [Line Items]
Outstanding	$ 4,444,688		$ 1,250,000	$ 1,179,688		$ 500,000	[1]		$ 350,000	[1]		$ 329,688
Basis			LIBOR + 2.00%			Fixed	[1]		Fixed	[1]		LIBOR + 2.00%
Rate			2.34%			2.60%	[1]		2.45%	[1]		2.22%
Long term debt	$ 4,941,764	$ 5,168,226	$ 1,250,000	$ 1,179,688	$ 1,250,000			$ 500,000			$ 350,000			$ 750,000
Fixed interest rate on derivative								0.60%			0.45%			0.91%
Debt instrument basis spread on fixed rate						200			200				200

[1] (1) Effective January 2012, $500 million of the U.S. Term Loans have been swapped to a fixed rate of 0.60% plus the specified spread under the Senior Credit Agreement, through January 2014. Effective March 2012, an additional $350 million of the U.S. Term Loans have been swapped to a fixed rate of 0.45% plus the specified spread under the Senior Credit Agreement, through March 2014. Effective June 2012, $750 million of the currently effective swaps have been extended to maturities ranging from March 2016 to November 2016, thereby fixing a rate of 0.91% plus the specified spread on the underlying U.S. Term Loans, for the extension period. As of September 30, 2012, the specified spread under the Senior Credit Agreement was 200 basis points. These swaps have been designated as cash flow hedges of the variability in interest expense related to our variable rate debt.At September 30, 2012, the fair value of the Senior Notes was approximately $2.60 billion,