Note 12 - Incentive Plans	3 Months Ended
Mar. 31, 2020
Notes to Financial Statements
Share-based Payment Arrangement [Text Block]	12. Incentive Plans The Company accounts for equity awards in accordance with FASB’s Compensation – Stock Compensation guidance which requires that all share-based payments to employees, including grants of employee stock options, restricted stock and performance shares, be recognized in the Condensed Consolidated Statements of Income over the service period based on their fair values. Fair value is determined, depending on the type of award, using either the Black-Scholes option pricing formula or the Monte Carlo method for performance shares, both of which are intended to estimate the fair value of the awards at the grant date. Fair value of restricted shares is calculated based on the price on the date of grant. The Company recognized expenses associated with its equity awards of $5.9 million and $5.5 million for the three months ended March 31, 2020 and 2019, respectively. As of March 31, 2020, the Company had $52.0 million of total unrecognized compensation cost related to unvested stock compensation granted under the Plans. That cost is expected to be recognized over a weighted average period of approximately 3.3 years.

Note 12 - Incentive Plans

3 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement [Text Block]

12. Incentive Plans

The Company accounts for equity awards in accordance with FASB’s Compensation – Stock Compensation guidance which requires that all share-based payments to employees, including grants of employee stock options, restricted stock and performance shares, be recognized in the Condensed Consolidated Statements of Income over the service period based on their fair values. Fair value is determined, depending on the type of award, using either the Black-Scholes option pricing formula or the Monte Carlo method for performance shares, both of which are intended to estimate the fair value of the awards at the grant date. Fair value of restricted shares is calculated based on the price on the date of grant.

The Company recognized expenses associated with its equity awards of $5.9 million and $5.5 million for the three months ended March 31, 2020 and 2019, respectively. As of March 31, 2020, the Company had $52.0 million of total unrecognized compensation cost related to unvested stock compensation granted under the Plans. That cost is expected to be recognized over a weighted average period of approximately 3.3 years.