Note 5 - Fair Value	3 Months Ended
Note 5 - Fair Value	Jun. 30, 2018
Notes to Financial Statements
Fair Value Disclosures [Text Block]	Note 5 : Fair Value The Company carries cash and cash equivalents and investments at fair value in the Condensed Consolidated Balance Sheets. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. ASC Topic 820 (“Fair Value Measurements”) establishes a three -tier fair value hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value: Level 1 - Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2 - Include other inputs that are directly or indirectly observable in the marketplace. Level 3 - Unobservable inputs which are supported by little or no market activity. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. At June 30, 2018, the Company had invested the majority of its $94.6 million cash and cash equivalents balance in money market funds which are classified within level 1.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.