Operations and Summary of Significant Accounting Policies (Details 8) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	$ 69,693
Accumulated amortization, balance at the beginning of the year	(19,095)
Net carrying amount, balance at the beginning of the year	50,598
Amortization	(7,100)	(7,800)	(4,300)
Gross carrying amount, balance at the end of the year	67,737	69,693
Accumulated amortization, balance at the end of the year	(25,964)	(19,095)
Net carrying amount, balance at the end of the year	41,773	50,598
Goodwill	129,218	121,981	99,849
Estimated future amortization of intangible assets
2014	7,078
2015	6,162
2016	5,905
2017	3,953
2018	3,059
Thereafter	9,950
Total	36,107
North America
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the end of the year	34,520	37,992
Accumulated amortization, balance at the end of the year	(15,909)	(12,012)
Net carrying amount, balance at the end of the year	18,611	25,980
Goodwill	84,822	78,739	73,901
Europe
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the end of the year	33,217	31,701
Accumulated amortization, balance at the end of the year	(10,055)	(7,083)
Net carrying amount, balance at the end of the year	23,162	24,618
Goodwill	42,690	41,263	24,000
S&P Clever
Changes in gross carrying amount of finite-lived intangible assets
Goodwill	19,000
Patents
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	6,684	6,681
Accumulated amortization, balance at the beginning of the year	(5,377)	(4,767)
Net carrying amount, balance at the beginning of the year	1,307	1,914
Amortization	(611)	(610)
Foreign exchange	5	3
Gross carrying amount, balance at the end of the year	6,689	6,684
Accumulated amortization, balance at the end of the year	(5,988)	(5,377)
Net carrying amount, balance at the end of the year	701	1,307
Unpatented Technology
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	5,361	4,129
Accumulated amortization, balance at the beginning of the year	(2,017)	(1,395)
Net carrying amount, balance at the beginning of the year	3,344	2,734
Disposal, Gross carrying amount	(1,530)
Disposal, Accumulated amortization	158
Disposal, Net carrying amount	(1,372)
Amortization	(3,398)	(622)
Foreign exchange	799	32
Reclassifications	14,347	1,200
Gross carrying amount, balance at the end of the year	18,977	5,361
Accumulated amortization, balance at the end of the year	(5,257)	(2,017)
Net carrying amount, balance at the end of the year	13,720	3,344
Non-Compete Agreements, Trademarks and Other
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	36,951	16,276
Accumulated amortization, balance at the beginning of the year	(3,002)	(5,361)
Net carrying amount, balance at the beginning of the year	33,949	10,915
Acquisition	4,130	32,355
Disposal, Gross carrying amount	(200)	(2,212)
Disposal, Accumulated amortization	74	1,628
Disposal, Net carrying amount	(126)	(584)
Amortization	(636)	(4,309)
Foreign exchange	(728)	(2)
Reclassifications	(26,588)	(4,426)
Removal of fully amortized asset, gross	(10)	(5,040)
Accumulated amortization of removal of fully amortized asset	10	5,040
Gross carrying amount, balance at the end of the year	13,555	36,951
Accumulated amortization, balance at the end of the year	(3,554)	(3,002)
Net carrying amount, balance at the end of the year	10,001	33,949
Customer Relationships
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	20,697	18,940
Accumulated amortization, balance at the beginning of the year	(8,699)	(6,647)
Net carrying amount, balance at the beginning of the year	11,998	12,293
Amortization	(2,465)	(2,052)
Foreign exchange	229	57
Reclassifications	1,923	1,700
Gross carrying amount, balance at the end of the year	22,849	20,697
Accumulated amortization, balance at the end of the year	(11,164)	(8,699)
Net carrying amount, balance at the end of the year	$ 11,685	$ 11,998