Operations and Summary of Significant Accounting Policies (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	$ 38,654
Accumulated amortization, balance at the beginning of the year	(15,188)
Net carrying amount, balance at the beginning of the year	23,466
Impairment	4,300
Gross carrying amount, balance at the end of the year	46,026
Accumulated amortization, balance at the end of the year	(18,170)
Net carrying amount, balance at the end of the year	27,856
Estimated future amortization of intangible assets
2012	5,102
2013	4,535
2014	4,322
2015	3,560
2016	3,425
Thereafter	6,912
Total	27,856
North America
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the end of the year	32,912	24,022
Accumulated amortization, balance at the end of the year	(13,288)	(10,792)
Net carrying amount, balance at the end of the year	19,624	13,230
Europe
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the end of the year	13,114	14,632
Accumulated amortization, balance at the end of the year	(4,882)	(4,396)
Net carrying amount, balance at the end of the year	8,232	10,236
Patents
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	6,921	6,939
Accumulated amortization, balance at the beginning of the year	(4,384)	(3,758)
Net carrying amount, balance at the beginning of the year	2,537	3,181
Amortization	(620)	(626)
Foreign exchange	(3)	(18)
Removal of fully amortized asset, gross	(237)
Accumulated amortization of removal of fully amortized asset	237
Gross carrying amount, balance at the end of the year	6,681	6,921
Accumulated amortization, balance at the end of the year	(4,767)	(4,384)
Net carrying amount, balance at the end of the year	1,914	2,537
Unpatented Technology
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	2,848	2,962
Accumulated amortization, balance at the beginning of the year	(879)	(481)
Net carrying amount, balance at the beginning of the year	1,969	2,481
Amortization	(516)	(398)
Foreign exchange	(66)	(114)
Reclassifications	1,347
Gross carrying amount, balance at the end of the year	4,129	2,848
Accumulated amortization, balance at the end of the year	(1,395)	(879)
Net carrying amount, balance at the end of the year	2,734	1,969
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	9,128	8,095
Accumulated amortization, balance at the beginning of the year	(4,311)	(3,223)
Net carrying amount, balance at the beginning of the year	4,817	4,872
Acquisition	9,026	1,633
Amortization	(1,297)	(1,358)
Impairment		(166)
Foreign exchange	(19)	(164)
Reclassifications	(1,612)
Removal of fully amortized asset, gross	(247)	(436)
Accumulated amortization of removal of fully amortized asset	247	436
Gross carrying amount, balance at the end of the year	16,276	9,128
Accumulated amortization, balance at the end of the year	(5,361)	(4,311)
Net carrying amount, balance at the end of the year	10,915	4,817
Customer Relationships
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	19,757	23,282
Accumulated amortization, balance at the beginning of the year	(5,614)	(4,964)
Net carrying amount, balance at the beginning of the year	14,143	18,318
Amortization	(1,893)	(2,190)
Impairment		(1,478)
Foreign exchange	(112)	(507)
Reclassifications	155
Removal of fully amortized asset, gross	(860)	(3,018)
Accumulated amortization of removal of fully amortized asset	860	3,018
Gross carrying amount, balance at the end of the year	18,940	19,757
Accumulated amortization, balance at the end of the year	(6,647)	(5,614)
Net carrying amount, balance at the end of the year	$ 12,293	$ 14,143