Other Transactions	12 Months Ended
Dec. 31, 2016
Other Events and Transactions [Abstract]
Other Transactions	Other Transactions NACoal: During the fourth quarter of 2016, NACoal recorded a $3.3 million charge related to the resolution of a legal matter. This charge is recorded on the line "Selling, general and administrative expenses" in the Consolidated Statements of Operations. During 2014, NACoal determined that indicators of impairment existed at Centennial and, as a result, reviewed Centennial's long-lived assets for impairment. NACoal recorded a non-cash, asset impairment charge of $105.1 million in 2014 for Centennial's long-lived asset group as "Centennial asset impairment charge" in the Consolidated Statements of Operations. During the third quarter of 2015, revisions were made to Centennial's asset retirement obligations due to revised estimated cash flows and the timing of those cash flows, resulting in a $7.5 million charge. Also as a result of its decision to cease mining operations, the Company recognized a $0.6 million charge for severance and other employee benefit costs in 2015. Both of these charges are recorded on the line "Cost of sales" in the Consolidated Statements of Operations. See Note 7 for further discussion of the Company's asset retirement obligations. Centennial ceased active mining operations at the end of 2015. As of December 31, 2015, the Company began actively marketing Centennial's mine machinery and equipment as assets held for sale. During the third quarter of 2016, the Company's NACoal subsidiary recorded an additional non-cash impairment charge of $17.4 million, reducing the carrying value of coal, land and real estate and assets held for sale at Centennial. These charges are recorded on the line "Centennial asset impairment charge" in the Consolidated Statements of Operations. See Note 10 for further discussion of the Company's asset impairment charges. During 2014, NACoal recognized a gain of $3.5 million from the sale of assets to Mississippi Power Company. These assets were previously classified as held for sale. Also during 2014, NACoal recognized an unrelated gain of $2.2 million from the sale of land. HBB: During 2014, HBB completed the acquisition of Weston Products, LLC, which HBB refers to as Weston Brands, in exchange for cash consideration of $25.4 million, of which $25.0 million was paid at closing and $0.4 million was paid in 2015. The results of Weston Brands operations have been included in the Company's Consolidated Financial Statements since December 16, 2014.

Other Transactions

NACoal: During the fourth quarter of 2016, NACoal recorded a $3.3 million charge related to the resolution of a legal matter. This charge is recorded on the line "Selling, general and administrative expenses" in the Consolidated Statements of Operations.

During 2014, NACoal determined that indicators of impairment existed at Centennial and, as a result, reviewed Centennial's long-lived assets for impairment. NACoal recorded a non-cash, asset impairment charge of $105.1 million in 2014 for Centennial's long-lived asset group as "Centennial asset impairment charge" in the Consolidated Statements of Operations. During the third quarter of 2015, revisions were made to Centennial's asset retirement obligations due to revised estimated cash flows and the timing of those cash flows, resulting in a $7.5 million charge. Also as a result of its decision to cease mining operations, the Company recognized a $0.6 million charge for severance and other employee benefit costs in 2015. Both of these charges are recorded on the line "Cost of sales" in the Consolidated Statements of Operations. See Note 7 for further discussion of the Company's asset retirement obligations.

Centennial ceased active mining operations at the end of 2015. As of December 31, 2015, the Company began actively marketing Centennial's mine machinery and equipment as assets held for sale. During the third quarter of 2016, the Company's NACoal subsidiary recorded an additional non-cash impairment charge of $17.4 million, reducing the carrying value of coal, land and real estate and assets held for sale at Centennial. These charges are recorded on the line "Centennial asset impairment charge" in the Consolidated Statements of Operations. See Note 10 for further discussion of the Company's asset impairment charges.

During 2014, NACoal recognized a gain of $3.5 million from the sale of assets to Mississippi Power Company. These assets were previously classified as held for sale. Also during 2014, NACoal recognized an unrelated gain of $2.2 million from the sale of land.

HBB: During 2014, HBB completed the acquisition of Weston Products, LLC, which HBB refers to as Weston Brands, in exchange for cash consideration of $25.4 million, of which $25.0 million was paid at closing and $0.4 million was paid in 2015. The results of Weston Brands operations have been included in the Company's Consolidated Financial Statements since December 16, 2014.