DESCRIPTION OF BUSINESS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended		36 Months Ended
	Sep. 30, 2012 countries	Dec. 31, 2011 region	Sep. 30, 2011	Sep. 30, 2012 segments countries	Sep. 30, 2011	Dec. 31, 2001 acquisition
Schedule Of Segment Reporting Information By Segment, Gross Margin [Line Items]
Gross margin, from external customer	$ 67,666		$ 92,992	$ 217,942	$ 269,657
Number of acquisitions (in acquisitions)						67
Number of countries in which entity operates (in countries)	20			20
Number of reportable segments (in segments)		3		3
Gross margin, percent of total	100.00%		100.00%	100.00%	100.00%
Minimum
Schedule Of Segment Reporting Information By Segment, Gross Margin [Line Items]
Number of employees (in employees)	2,000			2,000
Hudson Americas
Schedule Of Segment Reporting Information By Segment, Gross Margin [Line Items]
Gross margin, from external customer	9,587		13,662	33,776	37,040
Gross margin, percent of total	14.00%		15.00%	15.00%	14.00%
Hudson Asia Pacific
Schedule Of Segment Reporting Information By Segment, Gross Margin [Line Items]
Gross margin, from external customer	29,852		41,201	91,067	113,323
Gross margin, percent of total	44.00%		44.00%	42.00%	42.00%
Hudson Europe
Schedule Of Segment Reporting Information By Segment, Gross Margin [Line Items]
Gross margin, from external customer	$ 28,227		$ 38,129	$ 93,099	$ 119,294
Gross margin, percent of total	42.00%		41.00%	43.00%	44.00%