Operations and Summary of Significant Accounting Policies (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	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	$ 46,026
Accumulated amortization, balance at the beginning of the year	(18,170)
Net carrying amount, balance at the beginning of the year	27,856
Amortization	(7,800)
Gross carrying amount, balance at the end of the year	69,693
Accumulated amortization, balance at the end of the year	(19,095)
Net carrying amount, balance at the end of the year	50,598
Estimated future amortization of intangible assets
2013	9,260
2014	8,984
2015	6,426
2016	6,134
2017	4,401
Thereafter	15,393
Total	50,598
Patents
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	6,681	6,921
Accumulated amortization, balance at the beginning of the year	(4,767)	(4,384)
Net carrying amount, balance at the beginning of the year	1,914	2,537
Amortization	(610)	(620)
Foreign exchange	3	(3)
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	6,684	6,681
Accumulated amortization, balance at the end of the year	(5,377)	(4,767)
Net carrying amount, balance at the end of the year	1,307	1,914
Unpatented Technology
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	4,129	2,848
Accumulated amortization, balance at the beginning of the year	(1,395)	(879)
Net carrying amount, balance at the beginning of the year	2,734	1,969
Amortization	(622)	(516)
Foreign exchange	32	(66)
Reclassifications	1,200	1,347
Gross carrying amount, balance at the end of the year	5,361	4,129
Accumulated amortization, balance at the end of the year	(2,017)	(1,395)
Net carrying amount, balance at the end of the year	3,344	2,734
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	16,276	9,128
Accumulated amortization, balance at the beginning of the year	(5,361)	(4,311)
Net carrying amount, balance at the beginning of the year	10,915	4,817
Acquisition	32,355	9,026
Disposal, Gross carrying amount	(2,212)
Disposal, Accumulated amortization	1,628
Disposal, Net carrying amount	(584)
Amortization	(4,309)	(1,297)
Foreign exchange	(2)	(19)
Reclassifications	(4,426)	(1,612)
Removal of fully amortized asset, gross	(5,040)	(247)
Accumulated amortization of removal of fully amortized asset	5,040	247
Gross carrying amount, balance at the end of the year	36,951	16,276
Accumulated amortization, balance at the end of the year	(3,002)	(5,361)
Net carrying amount, balance at the end of the year	33,949	10,915
Customer Relationships
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the beginning of the year	18,940	19,757
Accumulated amortization, balance at the beginning of the year	(6,647)	(5,614)
Net carrying amount, balance at the beginning of the year	12,293	14,143
Amortization	(2,052)	(1,893)
Foreign exchange	57	(112)
Reclassifications	1,700	155
Removal of fully amortized asset, gross		(860)
Accumulated amortization of removal of fully amortized asset		860
Gross carrying amount, balance at the end of the year	20,697	18,940
Accumulated amortization, balance at the end of the year	(8,699)	(6,647)
Net carrying amount, balance at the end of the year	11,998	12,293
North America
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the end of the year	37,992	32,912
Accumulated amortization, balance at the end of the year	(12,012)	(13,288)
Net carrying amount, balance at the end of the year	25,980	19,624
Europe
Changes in gross carrying amount of finite-lived intangible assets
Gross carrying amount, balance at the end of the year	31,701	13,114
Accumulated amortization, balance at the end of the year	(7,083)	(4,882)
Net carrying amount, balance at the end of the year	$ 24,618	$ 8,232