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Debt - Term Loans (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Aug. 31, 2020	Mar. 31, 2021	Sep. 30, 2020	Dec. 31, 2020
Line of Credit Facility [Line Items]
Final payment fee		$ 2,300
Class of warrant or right, number of securities called by warrants or rights (in shares)	196,850
Exercise price (in dollars per share)	$ 2.54	$ 1.60
Class of warrant or right, expiration period	10 years
Adjustments to additional paid in capital, warrant issued	$ 400
2020 Term Loans
Line of Credit Facility [Line Items]
Maximum borrowing capacity	35,000
Debt instrument, additional accrued interest in the event of default		0.050
Debt instrument, redemption price, percentage of principal amount redeemed		9.00%
Debt instrument, default, bankruptcy, or insolvency value of triggering accelerated redemption	500
Debt issuance costs, line of credit arrangements (less than)	400
Term loan facility		$ 25,000		$ 25,000
Term A Loans
Line of Credit Facility [Line Items]
Maximum borrowing capacity	25,000
Term B Loans
Line of Credit Facility [Line Items]
Maximum borrowing capacity	10,000
2017 Term Loans
Line of Credit Facility [Line Items]
Repayments of lines of credit	13,700
Loss on extinguishment of debt			$ 500
Warrants to purchase common stock | Term B Loans
Line of Credit Facility [Line Items]
Sale common stock	$ 200,000
Maximum | 2020 Term Loans
Line of Credit Facility [Line Items]
Debt instrument, prepayment fee, percentage		0.030
Minimum | 2020 Term Loans
Line of Credit Facility [Line Items]
Debt instrument, prepayment fee, percentage		0.010
Debt Instrument, Redemption, Period One | 2020 Term Loans
Line of Credit Facility [Line Items]
Basis spread on variable rate		7.90%
Debt Instrument, Redemption, Period Two | 2020 Term Loans
Line of Credit Facility [Line Items]
Basis spread on variable rate		4.65%
Debt Instrument, Redemption, Period Three | 2020 Term Loans
Line of Credit Facility [Line Items]
Basis spread on variable rate		10.00%

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Amount of increase in additional paid in capital (APIC) resulting from the issuance of warrants. Includes allocation of proceeds of debt securities issued with detachable stock purchase warrants.

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Exercise price per share or per unit of warrants or rights outstanding.

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Amount, after accumulated amortization, of debt issuance costs related to line of credit arrangements. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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