Operations and Summary of Significant Accounting Policies (Details 7) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill Impairment Testing
Goodwill	$ 121,981	$ 129,218	$ 121,981	$ 99,849
Balance at the beginning of the year
Goodwill	145,531	152,768	145,531	121,053
Accumulated impairment losses	(23,550)	(23,550)	(23,550)	(21,204)
Goodwill at the beginning of the period, net		121,981	99,849
Goodwill acquired		1,592	22,826
Goodwill disposed		(480)
Foreign exchange		872	496
Impairment	(2,346)		(2,346)	(1,282)
Reclassifications		5,253	1,156
Balance at the end of the year
Goodwill	145,531	152,768	145,531	121,053
Accumulated impairment losses	(23,550)	(23,550)	(23,550)	(21,204)
Goodwill at the end of the period, net	121,981	129,218	121,981	99,849
Maximum
Goodwill Impairment Testing
Step 1 pass margin percentage criteria based on which sensitivity assessment of key assumption is done		10.00%
Keymark | Purchase price adjustment
Balance at the beginning of the year
Goodwill acquired			5,900
North America
Goodwill Impairment Testing
Goodwill	78,739	84,822	78,739
Balance at the beginning of the year
Goodwill	89,405	95,488	89,405	84,567
Accumulated impairment losses	(10,666)	(10,666)	(10,666)	(10,666)
Goodwill at the beginning of the period, net		78,739	73,901
Goodwill acquired		918	3,581
Goodwill disposed		(480)
Foreign exchange		(248)	101
Reclassifications		5,893	1,156
Balance at the end of the year
Goodwill	89,405	95,488	89,405	84,567
Accumulated impairment losses	(10,666)	(10,666)	(10,666)	(10,666)
Goodwill at the end of the period, net	78,739	84,822	78,739
Europe
Goodwill Impairment Testing
Goodwill	41,263	42,690	41,263	24,000
Balance at the beginning of the year
Goodwill	54,147	55,574	54,147	34,538
Accumulated impairment losses	(12,884)	(12,884)	(12,884)	(10,538)
Goodwill at the beginning of the period, net		41,263	24,000
Goodwill acquired		674	19,245
Foreign exchange		1,393	364
Impairment			(2,346)	(1,282)
Reclassifications		(640)
Balance at the end of the year
Goodwill	54,147	55,574	54,147	34,538
Accumulated impairment losses	(12,884)	(12,884)	(12,884)	(10,538)
Goodwill at the end of the period, net	41,263	42,690	41,263	24,000
Asia/Pacific
Goodwill Impairment Testing
Goodwill	1,979	1,706	1,979
Balance at the beginning of the year
Goodwill	1,979	1,706	1,979	1,948
Goodwill at the beginning of the period, net		1,979	1,948
Foreign exchange		(273)	31
Balance at the end of the year
Goodwill	1,979	1,706	1,979	1,948
Goodwill at the end of the period, net	1,979	1,706	1,979
Australia
Goodwill Impairment Testing
Marginal percentage by which the company passed annual impairment test		4.00%
Goodwill		1,700
Number of locations into which the activities will be consolidated		3
Margin by which the reporting units passed the annual goodwill impairment test
Step 1 Pass Margin (as a percent)		4.00%
Discount Rate Increases (as a percent)		2.00%
CAGR Decreases (as a percent)		2.00%
Pre-Tax Operating Margin Decreases (as a percent)		6.00%
Balance at the end of the year
Goodwill at the end of the period, net		1,700
United States
Goodwill Impairment Testing
Number of locations into which the activities will be consolidated		4
S&P Clever
Goodwill Impairment Testing
Marginal percentage by which the company passed annual impairment test		9.00%
Goodwill		19,000
Number of locations into which the activities will be consolidated		7
Margin by which the reporting units passed the annual goodwill impairment test
Step 1 Pass Margin (as a percent)		9.00%
Discount Rate Increases (as a percent)		7.00%
CAGR Decreases (as a percent)		6.00%
Pre-Tax Operating Margin Decreases (as a percent)		10.00%
Balance at the end of the year
Goodwill at the end of the period, net		19,000
France
Goodwill Impairment Testing
Marginal percentage by which the company passed annual impairment test		10.00%
Goodwill		14,900
Margin by which the reporting units passed the annual goodwill impairment test
Step 1 Pass Margin (as a percent)		10.00%
Discount Rate Increases (as a percent)		13.00%
CAGR Decreases (as a percent)		19.00%
Pre-Tax Operating Margin Decreases (as a percent)		15.00%
Balance at the end of the year
Goodwill at the end of the period, net		$ 14,900