Note 8 - Stock Options and Stock-based Employee Compensation - Summary of Stock Option Activity (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2016 $ / shares shares
Shares Outstanding, Beginning Balance (in shares) | shares	517
Weighted Average Exercise Price, Outstanding, at Beginning Period (in dollars per share) | $ / shares	$ 51.35
Shares Granted (in shares) | shares	763
Weighted Average Exercise Price, Granted (in dollars per share) | $ / shares	$ 2.09
Shares Forfeited or Expired (in shares) | shares	(138)
Weighted Average Exercise Price, Forfeited or Expired (in dollars per share) | $ / shares	$ 69.15
Shares Outstanding, Ending Balance (in shares) | shares	1,142
Weighted Average Exercise Price, Outstanding, at Ending Period (in dollars per share) | $ / shares	$ 16.30
Weighted Average Remaining Contractual Life, Outstanding	8 years 73 days
Shares Vested and Exercisable (in shares) | shares	303
Weighted Average Exercise Price, Vested and Exercisable (in dollars per share) | $ / shares	$ 49.97
Weighted Average Remaining Contractual Life, Vested and Exercisable	5 years 73 days