Financing Receivables	3 Months Ended
Mar. 31, 2017
Financing Receivables [Abstract]
Financing Receivables [Text Block]	Financing Receivables The Company had total financing receivables of $94.4 million and $84.8 million reflected in "Investments and other assets" in the condensed consolidated balance sheets as of March 31, 2017 and December 31, 2016, respectively. The Company periodically assesses the collectability of accounts and loans receivable by considering factors such as specific evaluation of collectability, historical collection experience, the age of the receivable and other available evidence. Below is a description of the Company's financing receivables outstanding as of March 31, 2017. Middlemount. The Company periodically makes loans (Priority Loans) to Middlemount Coal Pty Ltd (Middlemount), in which the Company owns a 50% equity interest, pursuant to the related shareholders’ agreement for purposes of funding capital expenditures and working capital requirements. The Priority Loans bear interest at a rate equal to the monthly average 30-day Australian Bank Bill Swap Reference Rate plus 3.5%. They were due to expire on December 31, 2016, but have been extended to June 30, 2017 in conjunction with a commercial agreement with the stockholders concerning the distribution of available cash against outstanding payables and the loans. The agreement requires the distribution of available cash at least twice each month. Available cash is defined as the amount of Middlemount's bank accounts that will not be required to pay known bills within the next 35 days. The available cash is distributed to stockholders in a 50/50 ratio, unless there is no marketing royalty payment overdue. In that situation, 100% of the available cash is distributed to the Company until its Priority Loans are repaid in full. Based on the existence of letters of support from related entities of the stockholders, the expected timing of repayment of these loans is projected to extend beyond the stated expiration date and so the Company considers these loans to be of a long-term nature. As a result, (i) the foreign currency impact related to the shareholder loans is included in foreign currency translation adjustment in the condensed consolidated balance sheets and the unaudited condensed consolidated statements of comprehensive income and (ii) interest income on the Priority Loans is recognized when cash is received. The carrying value of the loans of $94.4 million and $84.8 million was reflected in "Investments and other assets" in the condensed consolidated balance sheets as of March 31, 2017 and December 31, 2016, respectively. The Company received approximately $31.0 million and $2.0 million from Middlemount during the three month periods ended March 31, 2017 and 2016, respectively. On August 8, 2016, one of the Company's Australian subsidiaries and the other shareholder of Middlemount entered into an agreement to provide a revolving loan (Revolving Loans) to Middlemount not to exceed $60.0 million Australian dollars (Revolving Loan Limit). The Company’s participation in the Revolving Loans will not, at any time, exceed its 50% equity interest of the Revolving Loan Limit. The Revolving Loans bear interest at 15% per annum and expire on December 31, 2017. As of March 31, 2017 and December 31, 2016, the carrying value of the Revolving Loans due to the Company's Australian subsidiary was zero.

Financing Receivables

The Company had total financing receivables of $94.4 million and $84.8 million reflected in "Investments and other assets" in the condensed consolidated balance sheets as of March 31, 2017 and December 31, 2016, respectively.

The Company periodically assesses the collectability of accounts and loans receivable by considering factors such as specific evaluation of collectability, historical collection experience, the age of the receivable and other available evidence. Below is a description of the Company's financing receivables outstanding as of March 31, 2017.

Middlemount. The Company periodically makes loans (Priority Loans) to Middlemount Coal Pty Ltd (Middlemount), in which the Company owns a 50% equity interest, pursuant to the related shareholders’ agreement for purposes of funding capital expenditures and working capital requirements. The Priority Loans bear interest at a rate equal to the monthly average 30-day Australian Bank Bill Swap Reference Rate plus 3.5%. They were due to expire on December 31, 2016, but have been extended to June 30, 2017 in conjunction with a commercial agreement with the stockholders concerning the distribution of available cash against outstanding payables and the loans. The agreement requires the distribution of available cash at least twice each month. Available cash is defined as the amount of Middlemount's bank accounts that will not be required to pay known bills within the next 35 days. The available cash is distributed to stockholders in a 50/50 ratio, unless there is no marketing royalty payment overdue. In that situation, 100% of the available cash is distributed to the Company until its Priority Loans are repaid in full. Based on the existence of letters of support from related entities of the stockholders, the expected timing of repayment of these loans is projected to extend beyond the stated expiration date and so the Company considers these loans to be of a long-term nature. As a result, (i) the foreign currency impact related to the shareholder loans is included in foreign currency translation adjustment in the condensed consolidated balance sheets and the unaudited condensed consolidated statements of comprehensive income and (ii) interest income on the Priority Loans is recognized when cash is received. The carrying value of the loans of $94.4 million and $84.8 million was reflected in "Investments and other assets" in the condensed consolidated balance sheets as of March 31, 2017 and December 31, 2016, respectively. The Company received approximately $31.0 million and $2.0 million from Middlemount during the three month periods ended March 31, 2017 and 2016, respectively.

On August 8, 2016, one of the Company's Australian subsidiaries and the other shareholder of Middlemount entered into an agreement to provide a revolving loan (Revolving Loans) to Middlemount not to exceed $60.0 million Australian dollars (Revolving Loan Limit). The Company’s participation in the Revolving Loans will not, at any time, exceed its 50% equity interest of the Revolving Loan Limit. The Revolving Loans bear interest at 15% per annum and expire on December 31, 2017. As of March 31, 2017 and December 31, 2016, the carrying value of the Revolving Loans due to the Company's Australian subsidiary was zero.