Goodwill And Identified Intangible Assets - Useful Life (Details)	12 Months Ended
	Dec. 31, 2017
Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	1 year
Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	15 years
Acquired patents / core technology | Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	3 years
Acquired patents / core technology | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	15 years
Existing technology | Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	5 years
Existing technology | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	10 years
Customer contracts and related relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	3 years
Customer contracts and related relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	9 years
Trade name | Minimum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	4 years
Trade name | Maximum
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	10 years
Non-competition agreements
Finite-Lived Intangible Assets [Line Items]
Intangible assets estimated useful life	1 year