CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenue	$ 53,141	$ 119,353
Costs and expenses:
Operating expenses (excluding depreciation and amortization)	88,266	148,100
Corporate general and administrative	16,311	27,975
Depreciation and amortization	3,412	8,465
Research and development	7,213	8,863
(Gain) loss on disposal of long-lived assets	(94)	1,450
Impairment of fixed assets	69,975	0
Impairment of goodwill	11,706	0
Total costs and expenses	196,789	194,853
Loss from operations	(143,648)	(75,500)
Other (expense) income:
Gain on lease termination	576	0
Interest expense	(60)	(2,019)
Other income (expense), net	503	1,708
Total other income (expense)	1,019	(311)
Loss before income taxes	(142,629)	(75,811)
Income tax benefit (expense)	6,179	(262)
Loss from continuing operations	(136,450)	(76,073)
Income from discontinued operations, net of tax	0	42,158
Net loss	$ (136,450)	$ (33,915)
Basic and diluted earnings (loss) per common share:
Continuing operations (in dollars per share)	$ (2.00)	$ (1.29)
Discontinued operations, net of tax (in dollars per share)	0	0.72
Basic earnings (loss) per common share (in dollars per share)	$ (2.00)	$ (0.57)
Weighted average common shares:
Weighted average common shares used in computing basic and diluted loss per common share	68,312	58,750