Intangible Assets And Goodwill - Gross Carrying Amount and Accumulated Amortization of Finite-lived Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 44,684	$ 44,684
Accumulated Amortization	(33,150)	(30,817)
Net Carrying Amount	11,534	13,867
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	39,984	39,984
Accumulated Amortization	(32,602)	(30,817)
Net Carrying Amount	7,382	9,167
Content Library
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,700	4,700
Accumulated Amortization	(548)	0
Net Carrying Amount	$ 4,152	$ 4,700