Segment and Geographic Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) segment	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Revenues from External Customers and Long-Lived Assets [Line Items]
Number of operating segments | segment			1
Net revenue	$ 1,667	$ 10,861	$ 9,438	$ 28,326
Percentage of revenue by geographic segments	100.00%	100.00%	100.00%	100.00%
Long-lived assets	$ 576,791		$ 576,791		$ 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 revenue	$ 1,639	$ 9,565	$ 8,841	$ 24,970
Percentage of revenue by geographic segments	98.30%	88.10%	93.70%	88.10%
Long-lived assets	$ 570,936		$ 570,936		$ 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 revenue	$ 28	$ 1,252	$ 322	$ 3,147
Percentage of revenue by geographic segments	1.70%	11.50%	3.40%	11.10%
Long-lived assets	$ 5,855		$ 5,855		$ 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 revenue	$ 0	$ 44	$ 275	$ 209
Percentage of revenue by geographic segments	0.00%	0.40%	2.90%	0.80%