Intangible Assets and Goodwill (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Purchased patents
Amortization of intangible assets	$ 41,962	$ 37,138	$ 25,074
Estimated future amortization expense of intangible assets
Next Twelve Months	30,382
Year Two	19,942
Year Three	19,220
Year Four	12,683
Year Five	1,331
Thereafter	3,064
Finite-lived intangible assets	86,622
Indefinite-Lived Intangible Assets (Excluding Goodwill)	5,100
Intangible Assets, Net (Excluding Goodwill)	91,722	132,388
Customer contracts and contractual relationships
Estimated future amortization expense of intangible assets
Finite-lived intangible assets	20,168	27,209
Existing technology
Estimated future amortization expense of intangible assets
Finite-lived intangible assets	66,454	100,079
Favorable Contracts [Member]
Identified intangible assets assumed in the acquisitions
Cash received related to intangible assets	3,600	5,900
Estimated future amortization expense of intangible assets
Finite-lived intangible assets	$ 1,700	$ 3,600
Non-competition agreements
Identified intangible assets assumed in the acquisitions
Finite-Lived Intangible Asset, Useful Life	3 years	3 years
Estimated future amortization expense of intangible assets
Finite-lived intangible assets	$ 0	$ 0
Minimum
Identified intangible assets assumed in the acquisitions
Finite-Lived Intangible Asset, Useful Life	1 year	1 year
Minimum | Customer contracts and contractual relationships
Identified intangible assets assumed in the acquisitions
Finite-Lived Intangible Asset, Useful Life	1 year	1 year
Minimum | Existing technology
Identified intangible assets assumed in the acquisitions
Finite-Lived Intangible Asset, Useful Life	3 years	3 years