Acquisitions, Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross Cost, Customer relationships	50,105	50,105
Accumulated Amortization, Customer relationships	18,893	17,857
Net Balance, Customer relationships	31,212	32,248
Gross Cost, Patents	45,994	45,964
Accumulated Amortization, Patents	15,750	14,850
Net Balance, Patents	30,244	31,114
Gross Cost, Tradenames	7,959	7,959
Accumulated Amortization, Tradenames	4,863	4,525
Net Balance, Tradenames	3,096	3,434
Gross Cost, Non-compete agreements	4,989	4,989
Accumulated Amortization, Non-compete agreements	2,782	2,567
Net Balance, Non-compete agreements	2,207	2,422
Gross Cost, Other intangible assets	109,047	109,017
Accumulated Amortization, Other intangible assets	42,288	39,799
Net Balance, Other intangible assets	66,759	69,218
Minimum [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	3 years	3 years
Minimum [Member] | Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	2 years	2 years
Minimum [Member] | Tradenames [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	5 years	5 years
Minimum [Member] | Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	1 year	1 year
Maximum [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	16 years	16 years
Maximum [Member] | Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	19 years	19 years
Maximum [Member] | Tradenames [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	15 years	15 years
Maximum [Member] | Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life in Years	7 years	7 years