Note 7 - Deerfield Loan - Long-term Debt Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Deerfield Loan [Member]
Amortization of prepaid interest expense	$ 347	$ 420	$ 1,435	$ 420
Cash interest expense	191	150	191	1,451
Non-cash amortization of debt discount		138		1,287
Debt discount write-off		707		707
Amortization of debt costs		2		12
Write-off of debt costs		66		66
Total interest expense	$ 538	$ 1,483	1,626	3,943
Debt discount write-off				$ 707