Goodwill and Purchased Intangible Assets, Finite Lived Intangible Assets by Class (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 4,800,000	$ 5,600,000	$ 8,100,000	$ 17,600,000
Acceleration of the end of life of certain intangible assets, finite-lived	0		0	5,600,000
Cost of Revenues [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	3,600,000	4,700,000	6,000,000	15,500,000
Sales and Marketing Expense [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	800,000	600,000	1,300,000	1,400,000
General and Administrative Expense [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	400,000	300,000	800,000	700,000
Operating expense [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 1,200,000	$ 900,000	$ 2,100,000	$ 2,100,000