Note 12 - Stockholders' Equity (Details Textual) - USD ($)						12 Months Ended
	Aug. 31, 2020	Jul. 17, 2019	Jun. 14, 2019	Apr. 03, 2017	May 13, 2013	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2016
Preferred Stock, Shares Authorized (in shares)						1,000,000	1,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share)						$ 0.0001	$ 0.0001
Common Stock, Shares Authorized (in shares)						200,000,000	200,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)						$ 0.0001	$ 0.0001
Class of Warrant or Right, Exercised (in shares)								27,311
Class of Warrant or Right, Outstanding (in shares)		0
Temporary Equity, Dividends, Adjustment						$ 170,000	$ 0	$ 2,654,000
Proceeds from Issuance of Preferred Stock and Preference Stock						$ 0	85,000,000	0
Stock Repurchased During Period, Value							$ 127,000	$ 23,000
Common Stock [Member]
Stock Repurchased During Period, Shares (in shares)							8,517	1,895
Stock Repurchased During Period, Value							$ (0)	$ (0)
Stock and Warrant Repurchase Plan [Member]
Stock Repurchase Program, Additional Authorized Amount									$ 15,000,000.0
Stock Repurchase Program, Authorized Amount									$ 35,000,000.0
Warrants Repurchased During Period (in shares)						6,011,926
Warrants Repurchased During Period, Value						$ 14,700,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount						$ 12,000,000.0
Stock and Warrant Repurchase Plan [Member] | Common Stock [Member]
Stock Repurchased During Period, Shares (in shares)						875,218	8,517	1,895
Stock Repurchased During Period, Value						$ 8,300,000	$ 127,000	$ 23,000
Conversion From Preferred Stock to Common Stock [Member]
Conversion of Stock, Shares Converted (in shares)						5,000
Conversion of Stock, Shares Issued (in shares)						566,364
2015 Long-Term Incentive Compensation Plan [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)				3 years
Series A Redeemable Convertible Preferred Stock [Member]
Temporary Equity, Shares Issued (in shares)						80,000	85,000
Deferred Offering Costs						$ 2,700,000
Dividends Payable						$ 5,300,000	$ 1,700,000
Convertible Preferred Stock, Shares Reserved for Future Issuance (in shares)						9,100,000
Warrants Issued with Units Sold in Initial Public Offering [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)					1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)					$ 11.50
Warrant Exchange [Member]
Warrant Exchange, Common Stock to be Received (in shares)			0.385
Class of Warrant or Right, Outstanding (in shares)		9,935,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		3,824,959
Temporary Equity, Dividends, Adjustment		$ 2,700,000
Warrants Exchanged in Consent Solicitation [Member]
Non Warrant Exchange, Common Stock to be Received (in shares)			0.36575
Class of Warrant or Right, Outstanding (in shares)		125,763
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		45,981
IPO [Member]
Common Stock, Par or Stated Value Per Share (in dollars per share)					$ 0.0001
Units Sold During Period (in shares)					20,000,000
Shares Issued, Price Per Share (in dollars per share)					$ 10.00
Over-allotment Option Sold During Period (in shares)					2,000,000
Proceeds from Issuance or Sale of Equity, Total					$ 200,000,000.0
Number of Common Stock in Each Unit (in shares)					1
Number of Warrants in Each Unit (in shares)					0.5
Separation of Units Enforced, Period after Merger (Day)					30 days
Separation of Units Enforced, Termination Thereafter (Year)					5 years
Private Placement [Member] | Series A Redeemable Convertible Preferred Stock [Member]
Temporary Equity, Shares Issued (in shares)	85,000
Temporary Equity, Par or Stated Value Per Share (in dollars per share)	$ 0.0001
Temporary Equity, Redemption Price Per Share (in dollars per share)	$ 1,000
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 85,000,000.0
Preferred Stock, Dividend Rate, Percentage	6.00%
Convertible Preferred Stock, Conversion Price (in dollars per share)	$ 9.50