Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Note 10 - Share Option and Equity Incentive Plan (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Expense	$ 613,000	$ 658,000	$ 1,700,000	$ 1,900,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	4,100,000		$ 4,100,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)			2 years 4 months 24 days
Restricted Stock and Restricted Stock Units (RSUs) [Member]
Share-based Payment Arrangement, Expense	487,000	$ 325,000	$ 962,000	$ 741,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 4,600,000		$ 4,600,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)			2 years 8 months 12 days
2013 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)	3,600		454,001
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)	$ 12.92
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)	$ 5.85		$ 5.07
2013 Plan [Member] \| Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)			4 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)			10 years
2013 Plan [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in shares)	0		299,924
2013 Plan [Member] \| Restricted Stock Units (RSUs) [Member] \| Second Anniversary of Grant Date [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			40.00%
2013 Plan [Member] \| Restricted Stock Units (RSUs) [Member] \| Third Anniversary of Grant Date [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			30.00%
2013 Plan [Member] \| Restricted Stock Units (RSUs) [Member] \| Fourth Anniversary of Grant Date [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage			30.00%
2013 Plan [Member] \| Minimum [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)			$ 10.88
2013 Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share)			$ 12.96