Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2012

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

For comparative purposes, the following table presents assets and liabilities measured at fair value on a recurring basis as of December 31, 2011:

	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
Description	(Level 1)		(Level 2)		(Level 3)		Total
Investments held in conjunction with deferred compensation plan	$	—	$	23,542	$	—	$	23,542
Total assets	$	—	$	23,542	$	—	$	23,542
Benefits payable in conjunction with deferred compensation plan	$	—	$	23,729	$	—	$	23,729
Acquisition-related contingent consideration	—		—		17,738		17,738
Total liabilities	$	—	$	23,729	$	17,738	$	41,467

The following table presents assets and liabilities measured at fair value on a recurring basis as of December 31, 2012:

	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
Description	(Level 1)		(Level 2)		(Level 3)		Total
Investments held in conjunction with deferred compensation plan	$	—	$	28,775	$	—	$	28,775
Total assets	$	—	$	28,775	$	—	$	28,775
Benefits payable in conjunction with deferred compensation plan	$	—	$	28,867	$	—	$	28,867
Acquisition-related contingent consideration	—		—		17,285		17,285
Total liabilities	$	—	$	28,867	$	17,285	$	46,152

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

The following table reconciles the changes in the acquisition-related contingent consideration payable:

Balance as of December 31, 2011	$	17,738
Fair market value of contingent consideration from acquisitions during the year	4,653
Payment of contingent consideration	(6,550		)
Change in fair market value	1,275
Impact of foreign currency translation	169
Balance as of December 31, 2012	$	17,285