Goodwill and Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Intangible assets
Gross Carrying Amount	$ 42,639	$ 36,575
Accumulated Amortization	(17,250)	(15,924)
Intangible assets, net	$ 25,389	20,651
Weighted average amortization period	7 years
Developed technology
Intangible assets
Gross Carrying Amount	$ 23,854	17,495
Accumulated Amortization	(11,251)	(10,145)
Intangible assets, net	$ 12,603	7,350
Weighted average amortization period	5 years 2 months 12 days
Customer relationships
Intangible assets
Gross Carrying Amount	$ 12,009	12,009
Accumulated Amortization	(4,424)	(4,050)
Intangible assets, net	$ 7,585	7,959
Weighted average amortization period	8 years 4 months 24 days
Trademark/trade name
Intangible assets
Gross Carrying Amount	$ 6,776	6,776
Accumulated Amortization	(1,575)	(1,434)
Intangible assets, net	$ 5,201	5,342
Weighted average amortization period	12 years
Non-competition agreements
Intangible assets
Gross Carrying Amount		295
Accumulated Amortization		$ (295)