Derivative Financial Instruments (Narrative) (Details) - Jun. 30, 2015 - Commodity contracts |
USD ($)
$ / oz
|
USD ($)
oz
$ / oz
|
|---|---|---|
| Forward contracts | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Gain (loss) on derivatives | $ | $ (38,025) | $ (8,575) |
| Call option | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Gain (loss) on derivatives | $ | $ (22,191) | $ (82,846) |
| Number of silver ounces covered by contract | oz | 50,000 | |
| Call option | Silver | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Average forward price (in dollars per oz) | 18.20 | 18.20 |
| Forward contracts and call options | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Number of gold ounces covered by contract | oz | 9,675 | |
| Forward contracts and call options | Gold | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Average forward price (in dollars per oz) | 1,259 | 1,259 |
| Put option | Gold | ||
| Derivative Instruments, Gain (Loss) [Line Items] | ||
| Average forward price (in dollars per oz) | 1,103 | 1,103 |