Goodwill and Other Intangible Assets (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Mar. 31, 2012 Blaze Acquisition [Member]	Jun. 30, 2012 Cotendo Acquisition [Member]	Mar. 31, 2012 Cotendo Acquisition [Member]	Mar. 06, 2012 Cotendo Acquisition [Member]
Goodwill [Line Items]
Business acquisition purchase price allocation for goodwill					$ 15,068,000	$ 40,000	$ 241,646,000	$ 241,686,000
Identifiable intangible assets					5,100,000			43,800,000
Amortization of other intangible assets	5,463,000	4,292,000	10,230,000	8,569,000
Future amortization expense recognized in remainder of current year			10,700,000
Future amortization expense 2013			22,900,000
Future amortization expense 2014			17,600,000
Future amortization expense 2015			13,900,000
Future amortization expense 2016			$ 9,500,000