Segment and Geographic Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments | segment			1
Net revenues	$ (3,300)	$ 7,868	$ 6,138	$ 36,194
Percentage of revenue by geographic segments	100.00%	100.00%	100.00%	100.00%
Long-lived assets	$ 546,488		$ 546,488		$ 309,679
Percentage of long-lived assets by geographic segments	100.00%		100.00%		100.00%
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ (3,213)	$ 6,456	$ 5,628	$ 31,426
Percentage of revenue by geographic segments	97.30%	82.00%	91.70%	86.80%
Long-lived assets	$ 540,866		$ 540,866		$ 308,843
Percentage of long-lived assets by geographic segments	99.00%		99.00%		99.70%
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ (88)	$ 1,208	$ 234	$ 4,355
Percentage of revenue by geographic segments	2.70%	15.40%	3.80%	12.00%
Long-lived assets	$ 5,622		$ 5,622		$ 836
Percentage of long-lived assets by geographic segments	1.00%		1.00%		0.30%
Rest of world
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 1	$ 204	$ 276	$ 413
Percentage of revenue by geographic segments	0.00%	2.60%	4.50%	1.20%