Derivative Instruments and Hedging Activities (Tables)

12 Months Ended

Dec. 31, 2011

Derivative Instruments And Hedging Activities [Abstract]

Fair value of derivative instruments in the Balance Sheet

			Fair Value as of December  31,
Liability Derivatives	Balance Sheet Location		2011		2010
Derivatives designated as hedging instruments:
Interest rate swaps		Other long-term liabilities	$	(9,039)	$	(6,666)

Summary of Cash Flow Hedges

Derivatives in Cash Flow Hedging Relationships	Amount of Gain or (Loss)  Recognized in OCI on Derivatives, net of tax (Effective Portion)
	Year Ended December 31,
	2011		2010
Interest rate swaps	$	(1,484)	$	(2,264)

Changes in fair value of foreign exchange contracts

Derivatives Not Designated as Hedging Instruments	Location of Gain or (Loss) Recognized in		Amount of Gain or (Loss) Recognized in Income on Derivatives
	Income on		Year Ended December 31,
	Derivatives		2011		2010		2009
Foreign exchange derivative instruments		Other, net	$	(484)	$	(772)	$	(4,932)