Note 4 - Convertible Securities - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	Feb. 26, 2021	Mar. 31, 2022	Dec. 31, 2021
Convertible Securities Embedded Derivative [Line Items]
Preferred stock, par value		$ 0	$ 0
Series A Preferred Stock [Member] | Repurchase and Exchange Agreement [Member]
Convertible Securities Embedded Derivative [Line Items]
Stock exchanged during period shares	1,000,000
Series B Preferred Stock [Member]
Convertible Securities Embedded Derivative [Line Items]
Percentage of dividend payable on preferred stock	4.00%
Preferred stock, par value
Temporary equity fair value of preferred stock at the time of issuance	$ 95
Preferred stock conversion description		The Company will have the right to cause the mandatory conversion of the Series B Preferred Stock into shares of Common Stock at any time after the initial issuance of the Series B Preferred Stock if the closing price of the Common Stock has equaled or exceeded $14.50 (subject to adjustment in the same manner as the conversion price) for 45 trading days within a period of 60 consecutive trading days.
Common stock price equal or exceeds preferred stock conversion price	$ 14.50	$ 14.50
Fair value allocated to derivative liability	$ 1
Preferred stock, redemption date	May 28, 2026
Series B Preferred Stock [Member] | Repurchase and Exchange Agreement [Member]
Convertible Securities Embedded Derivative [Line Items]
Temporary equity exchange basis	one-for-one
Series B Preferred Stock [Member] | Purchase Agreement [Member]
Convertible Securities Embedded Derivative [Line Items]
Initial conversion rate of preferred stock to common stock	9.5238
Initial conversion price of preferred stock per share of common stock	$ 10.50
Series B Preferred Stock Embedded Derivative [Member] | Other Long-Term Liabilities [Member]
Convertible Securities Embedded Derivative [Line Items]
Estimated fair value of embedded derivative		$ 1	$ 1
Series C Preferred Stock [Member]
Convertible Securities Embedded Derivative [Line Items]
Fair value of the embedded derivative at issuance	$ 2
Series C Preferred Stock [Member] | After February 26, 2023 [Member]
Convertible Securities Embedded Derivative [Line Items]
Common stock price equal or exceeds preferred stock conversion price percentage		200.00%
Series C Preferred Stock [Member] | After February 26, 2024 [Member]
Convertible Securities Embedded Derivative [Line Items]
Common stock price equal or exceeds preferred stock conversion price percentage		150.00%
Series C Preferred Stock [Member] | Purchase Agreement [Member]
Convertible Securities Embedded Derivative [Line Items]
Preferred stock, par value
Initial conversion price of preferred stock per share of common stock	$ 10
Preferred stock, redemption date	May 28, 2026
Preferred stock, purchase agreement date	Feb. 26, 2021
Preferred stock, number of shares issued	1,000,000
Percentage of in-kind dividend payable on preferred stock	5.00%
Preferred stock, liquidation preference per share	$ 100
Gross proceeds owed on issuance of preferred stock	$ 100
Series C Preferred Stock [Member] | Dividend and Other Rights [Member]
Convertible Securities Embedded Derivative [Line Items]
Percentage of dividend payable on preferred stock	5.00%
Series C Preferred Stock Embedded Derivative [Member] | Other Long-Term Liabilities [Member]
Convertible Securities Embedded Derivative [Line Items]
Estimated fair value of embedded derivative		$ 1	2
2021 Convertible Notes Embedded Derivative [Member]
Convertible Securities Embedded Derivative [Line Items]
Fair value of the embedded derivative at issuance	$ 12
Estimated fair value of embedded derivative		$ 8	4
2021 Convertible Notes [Member]
Convertible Securities Embedded Derivative [Line Items]
Debt instrument, aggregate principal amount	$ 25
Debt instrument interest rate	5.00%
Maturity date of the convertible note	May 28, 2026
Debt Instrument Convertible Terms Of Conversion Feature	The Buyers will have the right to elect at any time to convert the Convertible Notes into shares of Common Stock at an initial conversion rate equal to 100 shares of Common Stock per each $1,000 principal amount of the Convertible Notes (based on an initial conversion price equal to $10.00 per share of Common Stock). The conversion rate and conversion price will be subject to certain customary anti-dilution adjustments.
Debt instrument, convertible, stock price	$ 14.50	$ 14.50
Carrying value of convertible notes		$ 15	$ 15
Estimated fair value of the convertible notes		$ 22