Note 8 - Shareholders' Equity (Tables)

6 Months Ended

Jun. 30, 2015

Stockholders' Equity Note [Abstract]

Schedule of Potential Per Share Dividend Amounts Quarterly Price Levels [Table Text Block]

Quarterly average realized silver price per ounce		Quarterly dividend per share		Annualized dividend per share
$	30	$	0.01	$	0.04
$	35	$	0.02	$	0.08
$	40	$	0.03	$	0.12
$	45	$	0.04	$	0.16
$	50	$	0.05	$	0.20