Current report of foreign issuer pursuant to Rules 13a-16 and 15d-16 Amendments

Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets) (Details)

v3.8.0.1
Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets) (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount $ 475,090 $ 477,301
Accumulated Amortization (342,279) (335,179)
Net Book Value 132,811 142,122
Developed technology [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 303,402 304,601
Accumulated Amortization (224,922) (220,420)
Net Book Value 78,480 84,181
Patents [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 18,512 19,708
Accumulated Amortization (14,115) (14,279)
Net Book Value 4,397 5,429
Trademarks and trade names [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 27,271 27,248
Accumulated Amortization (18,590) (18,245)
Net Book Value 8,681 9,003
Customer relationships [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 106,364 106,203
Accumulated Amortization (65,766) (63,435)
Net Book Value 40,598 42,768
Capitalized software development costs [Member]    
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 19,541 19,541
Accumulated Amortization (18,886) (18,800)
Net Book Value $ 655 $ 741