Note 16 - Share-based Compensation - Inputs Used for Valuation of Option Grants under Stock Option Plans (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Minimum [Member]
Expected volatility			38.60%	44.20%
Weighted-average volatility			38.60%	44.20%
Expected dividends			2.34%	1.92%
Risk-free rate			1.40%	1.90%
Average risk-free rate			1.40%	1.90%
Expected term (in years)			7 years 146 days	7 years 73 days
Pre-vesting departure rate			0.60%	0.60%
Maximum [Member]
Expected volatility			43.10%	44.90%
Weighted-average volatility			43.10%	44.90%
Expected dividends			2.94%	2.67%
Risk-free rate			1.60%	2.00%
Average risk-free rate			1.60%	2.00%
Expected term (in years)			7 years 146 days	7 years 73 days
Pre-vesting departure rate			0.60%	0.60%
Expected volatility	38.60%	44.20%
Weighted-average volatility	38.60%	44.20%
Expected dividends	2.34%	2.67%
Risk-free rate	1.40%	2.00%
Average risk-free rate	1.40%	2.00%
Expected term (in years)	7 years 146 days	7 years 73 days
Pre-vesting departure rate	0.60%	0.60%