Note 16 - Share-based Compensation - Inputs Used for Valuation of Option Grants under Stock Option Plans (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Minimum [Member]
Expected volatility			40.20%	44.50%
Weighted-average volatility			40.20%	44.50%
Expected dividends			2.89%	1.92%
Risk-free rate			1.50%	1.90%
Average risk-free rate			1.50%	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%	2.24%
Risk-free rate			1.60%	1.90%
Average risk-free rate			1.60%	1.90%
Expected term (in years)			7 years 146 days	7 years 73 days
Pre-vesting departure rate			0.60%	0.60%
Expected volatility	40.20%	44.50%
Weighted-average volatility	40.20%	44.50%
Expected dividends	2.89%	2.24%
Risk-free rate	1.60%	1.90%
Average risk-free rate	1.60%	1.90%
Expected term (in years)	7 years 146 days	7 years 73 days
Pre-vesting departure rate	0.60%	0.60%