Goodwill And Related Intangible Assets (Schedule Of Acquired Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived	$ 76,418	$ 52,650
Total acquired intangible assets, Gross Carrying Amount	123,178	88,053
Accumulated Amortization, Finite-lived	27,913	21,752
Total acquired intangible assets, Accumulated Amortization	27,913	21,752
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived	48,276	42,469
Accumulated Amortization, Finite-lived	20,512	16,832
Estimated Useful Life, Minimum years	5
Estimated Useful Life, Maximum years	16
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived	2,857	2,656
Accumulated Amortization, Finite-lived	2,303	1,921
Estimated Useful Life, Minimum years	5
Estimated Useful Life, Maximum years	10
Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived	1,200
Accumulated Amortization, Finite-lived	600
Estimated Useful Life, Minimum years	1
Estimated Useful Life, Maximum years	2
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Indefinite-lived	46,760	35,403
Gross Carrying Amount, Finite-lived	1,968	1,968
Accumulated Amortization, Finite-lived	921	760
Estimated Useful Life, Minimum years	2
Estimated Useful Life, Maximum years	15
Unpatented Technology And Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount, Finite-lived	22,117	5,557
Accumulated Amortization, Finite-lived	$ 3,577	$ 2,239
Estimated Useful Life, Minimum years	5
Estimated Useful Life, Maximum years	20