Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2014

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Finite-Lived Intangible Assets

Intangible assets other than goodwill, which are subject to amortization, consist of the following:

	Gross Carrying Amount		Accumulated Amortization			Net Balance
Balance at December 31, 2014
NACoal:
Coal supply agreements	$	84,200	$	(33,421	)	$	50,779
Other intangibles	—		—			—
	$	84,200	$	(33,421	)	$	50,779
HBB:
Customer relationships	$	5,760	$	(40	)	$	5,720
Trademarks	3,100		(8		)	3,092
Other intangibles	1,240		(10		)	1,230
	$	10,100	$	(58	)	$	10,042
Balance at December 31, 2013
NACoal:
Coal supply agreements	$	91,480	$	(32,492	)	$	58,988
Other intangibles	950		(253		)	697
	$	92,430	$	(32,745	)	$	59,685