Assets - Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Goodwill
Changes in goodwill during the period	$ 0
Intangible assets
Accumulated Amortization and Impairment	147,810	$ 146,221
Total Gross Intangible Assets	203,321	204,599
Total Net Intangible Assets	55,511	58,378
Indefinite-lived trademark
Intangible assets
Indefinite-lived intangible assets	2,900	2,900
Technology
Intangible assets
Gross Carrying Amount	149,198	149,198
Accumulated Amortization and Impairment	115,454	113,904
Net Amount	33,744	35,294
Customer relationships
Intangible assets
Gross Carrying Amount	47,885	47,885
Accumulated Amortization and Impairment	29,909	28,659
Net Amount	17,976	19,226
Trademark and tradenames
Intangible assets
Gross Carrying Amount	2,590	2,590
Accumulated Amortization and Impairment	1,986	1,948
Net Amount	604	642
Other
Intangible assets
Gross Carrying Amount	748	2,026
Accumulated Amortization and Impairment	461	1,710
Net Amount	$ 287	$ 316