Note 9 - Fair Value Measurements - Discounted Cash Flow Assumptions (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Minimum [Member]
Expected return	3.70%	4.30%
Maximum [Member]
Expected return	6.70%	7.30%
Time-to-liquidity (months)	2 years	2 years
Expected return	2.50%	2.90%