Discontinued Operations - Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets held for sale:
Total current assets held for sale	$ 2,619	$ 2,176
Non-current assets held for sale:
Total non-current assets held for sale	3,705	3,895
Current liabilities held for sale:
Total current liabilities held for sale	2,001	2,002
Non-current liabilities held for sale:
Total non-current liabilities held for sale	3,317	3,543
Held for Sale
Current assets held for sale:
Cash and cash equivalents	1,928	1,059
Short-term investments	0	517
Prepaid expenses and other assets	691	600
Total current assets held for sale	2,619	2,176
Non-current assets held for sale:
Right-of-use lease assets	3,351	3,607
Other non-current assets	354	288
Total non-current assets held for sale	3,705	3,895
Total assets held for sale	6,324	6,071
Current liabilities held for sale:
Accrued salaries and employee benefits	1,514	1,645
Accounts payable and accrued liabilities	268	163
Short-term lease liabilities	219	194
Total current liabilities held for sale	2,001	2,002
Non-current liabilities held for sale:
Non-current lease liabilities	3,317	3,543
Total non-current liabilities held for sale	3,317	3,543
Total liabilities held for sale	$ 5,318	$ 5,545