Note 6 - Stock-based Compensation	6 Months Ended
Note 6 - Stock-based Compensation	Jun. 30, 2016
Notes to Financial Statements
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	6. Stock-Based Compensation We account for share-based awards in accordance with ASC 718 which requires that the cost resulting from all share-based payment transactions be recognized in the financial statements. ASC 718 requires all entities to apply a fair value-based measurement method in accounting for share-based payment transactions with employees except for equity instruments held by employee share ownership plans. Total compensation expense recognized related to stock-based compensation was $3.7 million and $2.4 million for the three months ended June 30, 2016 and 2015, respectively. For the six months ended June 30, 2016 and 2015, we recognized stock-based compensation expense of $7.5 million and $5.1 million, respectively. As of June 30, 2016, total unrecognized stock-based compensation expense was $27.3 million, with a weighted average period over which the remaining unrecognized compensation expense is expected to be recorded of approximately 2.2 years.

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.