Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Cost [Abstract]
Beginning balance	$ 256,842
Foreign currency translation	(2,716)
Ending balance	254,126		256,842
Accumulated impairment [Abstract]
Beginning balance	(44,939)
Foreign currency translation	1,788
Ending balance	(43,151)		(44,939)
Net book value [Abstract]
Beginning balance	211,903
Ending balance	210,975		211,903
Other intangible assets subject to amortization [Abstract]
Weighted Average Life	12 years 10 months 24 days		13 years
Cost	61,599		62,632
Accumulated Amortization	(33,510)		(32,989)
Net	28,089		29,643
Period over which acquired companies have had key relationships with fortune 500 companies, minimum	15 years
Amortization expense related to other intangible assets	1,049	1,355
Finite-Lived Intangible Assets, Future Amortization Expense [Abstract]
Future amortization expense, 2014	4,031
Future amortization expense, 2015	3,991
Future amortization expense, 2016	3,851
Future amortization expense, 2017	3,774
Future amortization expense, 2018	3,543
Customer relationships [Member]
Other intangible assets subject to amortization [Abstract]
Weighted Average Life	13 years 8 months 12 days		13 years 8 months 12 days
Cost	56,908		57,904
Accumulated Amortization	(29,396)		(28,894)
Net	27,512		29,010
Digital images [Member]
Other intangible assets subject to amortization [Abstract]
Weighted Average Life	5 years		5 years
Cost	450		450
Accumulated Amortization	(450)		(450)
Net	0		0
Developed technologies [Member]
Other intangible assets subject to amortization [Abstract]
Weighted Average Life	3 years		3 years
Cost	712		712
Accumulated Amortization	(712)		(712)
Net	0		0
Non-compete agreements [Member]
Other intangible assets subject to amortization [Abstract]
Weighted Average Life	3 years 7 months 6 days		3 years 7 months 6 days
Cost	868		877
Accumulated Amortization	(816)		(821)
Net	52		56
Trade names [Member]
Other intangible assets subject to amortization [Abstract]
Weighted Average Life	3 years 10 months 24 days		3 years 10 months 24 days
Cost	1,441		1,469
Accumulated Amortization	(916)		(892)
Net	525		577
Contract acquisition cost [Member]
Other intangible assets subject to amortization [Abstract]
Weighted Average Life	3 years		3 years
Cost	1,220		1,220
Accumulated Amortization	(1,220)		(1,220)
Net	0		0
Americas [Member]
Cost [Abstract]
Beginning balance	203,987
Foreign currency translation	(446)
Ending balance	203,541
Accumulated impairment [Abstract]
Beginning balance	(14,540)
Foreign currency translation	105
Ending balance	(14,435)
Net book value [Abstract]
Beginning balance	189,447
Ending balance	189,106
Europe [Member]
Cost [Abstract]
Beginning balance	43,025
Foreign currency translation	(2,235)
Ending balance	40,790
Accumulated impairment [Abstract]
Beginning balance	(29,129)
Foreign currency translation	1,689
Ending balance	(27,440)
Net book value [Abstract]
Beginning balance	13,896
Ending balance	13,350
Asia Pacific [Member]
Cost [Abstract]
Beginning balance	9,830
Foreign currency translation	(35)
Ending balance	9,795
Accumulated impairment [Abstract]
Beginning balance	(1,270)
Foreign currency translation	(6)
Ending balance	(1,276)
Net book value [Abstract]
Beginning balance	8,560
Ending balance	8,519
Asia Pacific [Member] | Customer relationships [Member]
Other intangible assets subject to amortization [Abstract]
Impairment of intangible assets	27
Asia Pacific [Member] | Trade names [Member]
Other intangible assets subject to amortization [Abstract]
Impairment of intangible assets	$ 9