Business Acquisitions (Details) (USD $)	12 Months Ended		0 Months Ended				12 Months Ended			0 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended		0 Months Ended
	Dec. 31, 2012 acquisition	Dec. 31, 2012 Verivue, FastSoft, Cotendo and Blaze [Member]	Dec. 04, 2012 Verivue [Member]	Sep. 13, 2012 FastSoft [Member]	Mar. 06, 2012 Cotendo [Member]	Feb. 07, 2012 Blaze [Member]	Dec. 31, 2011 Velocitude [Member]	Dec. 31, 2010 Velocitude [Member]	Jun. 30, 2010 Velocitude [Member]	Mar. 06, 2012 Completed Technology [Member] Cotendo [Member]	Dec. 31, 2012 Customer Relationships [Member]	Dec. 31, 2011 Customer Relationships [Member]	Mar. 06, 2012 Customer Relationships [Member] Cotendo [Member]	Dec. 31, 2012 Noncompete Agreements [Member]	Dec. 31, 2011 Noncompete Agreements [Member]	Mar. 06, 2012 Noncompete Agreements [Member] Cotendo [Member]	Dec. 31, 2012 Trademarks and Trade Names [Member]	Dec. 31, 2011 Trademarks and Trade Names [Member]	Mar. 06, 2012 Trademarks and Trade Names [Member] Cotendo [Member]
Business Acquisition [Line Items]
Number of acquisitions (in acquisition)	4
Acquisition related costs		$ 5,800,000
Cost of aquired entity, cash paid			30,900,000	14,400,000					12,000,000
Contingent consideration			1,200,000						2,400,000
Weighted average useful life			6 years 4 months 24 days	9 years	7 years 1 month 6 days	5 years 3 months 18 days				6 years	9 years	9 years	9 years	5 years	4 years	6 years	9 years	4 years	10 years
Gross carrying amount, intangible assets					43,800,000					24,100,000			13,400,000			3,900,000			2,400,000
Allocation of the purchase consideration
Current assets, including cash and cash equivalents of $6,405					6,751,000
Trade receivables					2,920,000
Property and equipment					5,812,000
Indemnification assets					6,200,000
Long-term assets					75,000
Identifiable intangible assets			7,500,000	3,700,000	43,800,000	5,100,000			2,800,000
Goodwill			20,700,000	8,800,000	233,828,000	15,100,000			11,600,000
Deferred tax liabilities					(15,376,000)
Other liabilities assumed					(5,133,000)
Total purchase consideration					278,877,000	19,300,000
Goodwill, expected tax deductible amount			5,600,000	2,000,000	45,000,000	13,500,000
Weighted average cost of capital					15.00%
Royalty rate for intangible assets										15.00%									1.00%
Discount rate										16.00%			16.00%			16.00%			16.00%
Tax rate for intangible assets										39.00%			39.00%			39.00%			39.00%
Payment related to contingent consideration							600,000	700,000
Decreased fair value of liability							$ 400,000	$ 700,000