Goodwill and Other Intangible Assets (Narrative) (Details) (USD $)	12 Months Ended					12 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Verivue [Member]	Dec. 04, 2012 Verivue [Member]	Dec. 31, 2012 FastSoft [Member]	Sep. 13, 2012 FastSoft [Member]	Dec. 31, 2012 Cotendo [Member]	Mar. 06, 2012 Cotendo [Member]	Dec. 31, 2012 Blaze [Member]	Feb. 07, 2012 Blaze [Member]
Business Acquisition [Line Items]
Purchase price allocation associated with acquisition				$ 20,690,000		$ 8,825,000		$ 233,828,000		$ 15,068,000
Identifiable intangible assets					7,500,000		3,700,000		43,800,000		5,100,000
Amortization of other intangible assets	20,962,000	17,070,000	16,657,000
Future amortization expense, 2013	24,300,000
Future amortization expense, 2014	19,300,000
Future amortization expense, 2015	16,600,000
Future amortization expense, 2016	11,700,000
Future amortization expense, 2017	$ 7,600,000