Note 8 - Capital Stock and Stock-based Compensation - Stock Option and Restricted Stock Unit Activity (Details)	3 Months Ended
	Mar. 31, 2022 $ / shares shares
Opening Balance, Stock Options Outstanding (in shares) | shares	1,404,816
Options, Outstanding, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 3.10
Options, Granted in Period (in shares) | shares	0
Options, Granted in Period, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 0
Options, exercised (in shares) | shares	(10,987)
Options, exercised, weighted average exercise price (in dollars per share) | $ / shares	$ 2.78
Options, Cancelled / Forfeited in Period (in shares) | shares	(3,126)
Options, Cancelled / Forfeited, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 3.79
Opening Balance, Stock Options Outstanding (in shares) | shares	1,390,703
Options, Outstanding, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 3.10
Restricted Stock Units (RSUs) [Member]
Restricted Stock Units Outstanding , Balance (in shares) | shares	1,141,164
Restricted Stock Units Outstanding , Grant Date Fair Value, Balance (in dollars per share) | $ / shares	$ 3.57
Restricted Stock Units, Granted in Period (in shares) | shares	518,163
Restricted Stock Units Granted , Grant Date Fair Value, Balance (in dollars per share) | $ / shares	$ 5.52
Restricted Stock Units, Vested in Period (in shares) | shares	(151,185)
Restricted Stock Units, Vested , Grant Date Fair Value, Balance (in dollars per share) | $ / shares	$ 2.30
Restricted Stock Units, Cancelled / Forfeited in Period (in shares) | shares	(12,917)
Restricted Stock Units, Cancelled/ Forfeited , Grant Date Fair Value, Balance (in dollars per share) | $ / shares	$ 3.07
Restricted Stock Units Outstanding , Balance (in shares) | shares	1,495,225
Restricted Stock Units Outstanding , Grant Date Fair Value, Balance (in dollars per share) | $ / shares	$ 4.37
Market Condition Restricted Stock Units [Member]
Restricted Stock Units Outstanding , Balance (in shares) | shares	860,155
Restricted Stock Units Outstanding , Grant Date Fair Value, Balance (in dollars per share) | $ / shares	$ 3.13
Restricted Stock Units, Granted in Period (in shares) | shares	205,122
Restricted Stock Units Granted , Grant Date Fair Value, Balance (in dollars per share) | $ / shares	$ 5.92
Restricted Stock Units, Vested in Period (in shares) | shares	0
Restricted Stock Units, Vested , Grant Date Fair Value, Balance (in dollars per share) | $ / shares	$ 0
Restricted Stock Units, Cancelled / Forfeited in Period (in shares) | shares	0
Restricted Stock Units, Cancelled/ Forfeited , Grant Date Fair Value, Balance (in dollars per share) | $ / shares	$ 0
Restricted Stock Units Outstanding , Balance (in shares) | shares	1,065,277
Restricted Stock Units Outstanding , Grant Date Fair Value, Balance (in dollars per share) | $ / shares	$ 3.67