Note 10 - Capitalization of Interest (Details Textual) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015
1.625% Convertible Senior Notes due May 2018 [Member]
Debt Instrument, Increase (Decrease) In Interest Incurred, Net of Interest Capitalized, Valuation of Business Combination		$ 9.0
Debt Instrument, Interest Rate, Stated Percentage	1.625%	1.625%	1.625%
Capitalized Interest Transferred from Investments in Unconsolidated Joint Ventures to Inventories Owned	$ 1.6	$ 2.1