Gold Stream Arrangement	9 Months Ended
Sep. 30, 2013
Gold Stream Arrangement [Abstract]
Gold Stream Arrangement	Gold Stream Arrangement Pursuant to an agreement dated October 2010, as subsequently amended in December 2011 and August 2012, with a subsidiary of Royal Gold, Inc. ("Royal Gold") (referred to as the "Gold Stream Arrangement"), TCM agreed to sell Royal Gold 52.25% of the refined gold production from Mt. Milligan for a total upfront payment of $781.5 million plus $435 per ounce, or the prevailing market rate if lower than $435 per ounce, when the gold is delivered. Pursuant to this Gold Stream Arrangement, through September 30, 2013, TCM has received total cash payments of $781.5 million from Royal Gold, comprised of a payment of $12.9 million on September 1, 2013, $37.0 million on June 1, 2013, $62.0 million on March 4, 2013, and payments of $305.0 million in 2012, $138.1 million in 2011 and $226.5 million in 2010. TCM must maintain a deposit record during the term of the Gold Stream Arrangement wherein TCM reduces the $781.5 million paid by Royal Gold by the difference between the current market price, if higher than $435 per ounce at the time of a sale of refined gold to Royal Gold, and $435 per ounce, multiplied by the amount of refined gold sold in such sale. If, at the end of the initial 50-year term of the agreement, the total deposit amount reflected in the deposit record has not been reduced to nil, TCM must pay to Royal Gold the remaining balance reflected in the deposit record. Royal Gold has a security interest in all of the Mt. Milligan assets until its total deposit amount has been reduced to nil. Royal Gold's security interest is subject to subordination to project or corporate financings by TCM, except that, in such circumstances, Royal Gold retains a first priority interest in 52.25% of the refined gold from Mt. Milligan. The agreement with Royal Gold also restricts TCM's ability to incur debt in excess of $350 million that is secured by the Mt. Milligan assets until the earlier of the date upon which 425,000 ounces of refined gold have been sold and delivered to Royal Gold pursuant to the agreement or the date upon which the aggregate dollar amount of the difference between the market price for the gold delivered to Royal Gold under the agreement and the price actually paid by Royal Gold pursuant to the terms of the agreement exceeds $280 million. After the total deposit amount has been reduced to nil, Royal Gold's security will consist solely of its first priority interest in 52.25% of the refined gold. The cash payments received under the Gold Stream Arrangement are recorded as deferred revenue in TCM's Condensed Consolidated Balance Sheets. Once Mt. Milligan is in production and begins delivering gold to Royal Gold, the liability will be amortized over the life of the mine based on the amount of gold delivered. In the event of any default under the Gold Stream Arrangement, Royal Gold could require TCM to repay the deposits received from Royal Gold, which amounts totaled $781.5 million as of September 30, 2013.

Gold Stream Arrangement

Pursuant to an agreement dated October 2010, as subsequently amended in December 2011 and August 2012, with a subsidiary of Royal Gold, Inc. ("Royal Gold") (referred to as the "Gold Stream Arrangement"), TCM agreed to sell Royal Gold 52.25% of the refined gold production from Mt. Milligan for a total upfront payment of $781.5 million plus $435 per ounce, or the prevailing market rate if lower than $435 per ounce, when the gold is delivered. Pursuant to this Gold Stream Arrangement, through September 30, 2013, TCM has received total cash payments of $781.5 million from Royal Gold, comprised of a payment of $12.9 million on September 1, 2013, $37.0 million on June 1, 2013, $62.0 million on March 4, 2013, and payments of $305.0 million in 2012, $138.1 million in 2011 and $226.5 million in 2010.

TCM must maintain a deposit record during the term of the Gold Stream Arrangement wherein TCM reduces the $781.5 million paid by Royal Gold by the difference between the current market price, if higher than $435 per ounce at the time of a sale of refined gold to Royal Gold, and $435 per ounce, multiplied by the amount of refined gold sold in such sale. If, at the end of the initial 50-year term of the agreement, the total deposit amount reflected in the deposit record has not been reduced to nil, TCM must pay to Royal Gold the remaining balance reflected in the deposit record.

Royal Gold has a security interest in all of the Mt. Milligan assets until its total deposit amount has been reduced to nil. Royal Gold's security interest is subject to subordination to project or corporate financings by TCM, except that, in such circumstances, Royal Gold retains a first priority interest in 52.25% of the refined gold from Mt. Milligan. The agreement with Royal Gold also restricts TCM's ability to incur debt in excess of $350 million that is secured by the Mt. Milligan assets until the earlier of the date upon which 425,000 ounces of refined gold have been sold and delivered to Royal Gold pursuant to the agreement or the date upon which the aggregate dollar amount of the difference between the market price for the gold delivered to Royal Gold under the agreement and the price actually paid by Royal Gold pursuant to the terms of the agreement exceeds $280 million. After the total deposit amount has been reduced to nil, Royal Gold's security will consist solely of its first priority interest in 52.25% of the refined gold. The cash payments received under the Gold Stream Arrangement are recorded as deferred revenue in TCM's Condensed Consolidated Balance Sheets. Once Mt. Milligan is in production and begins delivering gold to Royal Gold, the liability will be amortized over the life of the mine based on the amount of gold delivered.

In the event of any default under the Gold Stream Arrangement, Royal Gold could require TCM to repay the deposits received from Royal Gold, which amounts totaled $781.5 million as of September 30, 2013.