Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 195,191	$ 135,061
Accumulated Amortization	(110,637)	(89,675)
Net Carrying Amount	84,554	45,386
Completed Technologies [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	71,531	36,731
Accumulated Amortization	(32,842)	(22,913)
Net Carrying Amount	38,689	13,818
Weighted average amortization period	6 years	6 years
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	104,700	88,700
Accumulated Amortization	(68,702)	(60,202)
Net Carrying Amount	35,998	28,498
Weighted average amortization period	9 years	9 years
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	14,770	8,340
Accumulated Amortization	(7,645)	(5,270)
Net Carrying Amount	7,125	3,070
Weighted average amortization period	5 years	4 years
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,700	800
Accumulated Amortization	(958)	(800)
Net Carrying Amount	2,742	0
Weighted average amortization period	9 years	4 years
Acquired License Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	490	490
Accumulated Amortization	(490)	(490)
Net Carrying Amount	$ 0	$ 0
Weighted average amortization period	10 years	10 years