Goodwill and Other Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of Intangible Assets [Abstract]
Gross Carrying Value	$ 292,481	$ 292,481
Accumulated Amortization	(254,375)	(230,426)
Net Carrying Value	38,106	62,055
Amortization of intangible assets	23,949	23,791	$ 23,644
Customer relationships
Components of Intangible Assets [Abstract]
Gross Carrying Value	141,973	141,973
Accumulated Amortization	(121,141)	(106,944)
Net Carrying Value	20,832	35,029
Developed technology
Components of Intangible Assets [Abstract]
Gross Carrying Value	134,542	134,542
Accumulated Amortization	(121,634)	(113,303)
Net Carrying Value	12,908	21,239
Trade names
Components of Intangible Assets [Abstract]
Gross Carrying Value	14,629	14,629
Accumulated Amortization	(10,416)	(9,198)
Net Carrying Value	4,213	5,431
Non-compete agreements
Components of Intangible Assets [Abstract]
Gross Carrying Value	1,337	1,337
Accumulated Amortization	(1,184)	(981)
Net Carrying Value	153	356
Cost of revenue
Components of Intangible Assets [Abstract]
Amortization of intangible assets	8,331	8,206	8,136
Sales and marketing
Components of Intangible Assets [Abstract]
Amortization of intangible assets	14,197	14,195	14,198
General and administrative
Components of Intangible Assets [Abstract]
Amortization of intangible assets	$ 1,421	$ 1,390	$ 1,310