Assets - Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Intangible assets
Total Gross Intangible Assets	$ 508,969	$ 508,969
Accumulated Amortization and Impairment	451,289	447,451
Total Net Intangible Assets	57,680	61,518
Technology
Intangible assets
Gross Carrying Amount, Definite-lived intangible assets	327,908	327,908
Accumulated Amortization and Impairment, Definite-lived intangible assets	294,414	291,766
Net Amount, Definite-lived intangible assets	33,494	36,142
Customer relationships
Intangible assets
Gross Carrying Amount, Definite-lived intangible assets	146,465	146,465
Accumulated Amortization and Impairment, Definite-lived intangible assets	127,606	126,764
Net Amount, Definite-lived intangible assets	18,859	19,701
Trademarks and tradenames
Intangible assets
Gross Carrying Amount, Definite-lived intangible assets	30,910	30,910
Accumulated Amortization and Impairment, Definite-lived intangible assets	25,596	25,256
Net Amount, Definite-lived intangible assets	5,314	5,654
Other Intangible Assets
Intangible assets
Gross Carrying Amount, Definite-lived intangible assets	3,686	3,686
Accumulated Amortization and Impairment, Definite-lived intangible assets	3,673	3,665
Net Amount, Definite-lived intangible assets	$ 13	$ 21