Current and Long-Term Financing (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Schedule of Debt

The following table summarizes the Company's available and outstanding borrowings:

	December 31
	2017			2016
Total outstanding borrowings of NACoal:
Revolving credit agreement	$	50,000		$	80,000
Capital lease obligations and other term loans	8,146			16,039
Total debt outstanding	$	58,146		$	96,039
Current portion of borrowings outstanding	$	16,125		$	1,744
Long-term portion of borrowings outstanding	42,021			94,295
	$	58,146		$	96,039
Total available borrowings, net of limitations, under revolving credit agreement	$	148,591		$	223,933
Unused revolving credit agreement	$	98,591		$	143,933
Weighted average stated interest rate on total borrowings	3.8		%	2.9		%
Weighted average effective interest rate on total borrowings (including interest rate swap agreements)	3.6		%	3.4		%

Schedule of Maturities of Total Debt, Excluding Capital Leases

Annual maturities of total debt, excluding capital leases, are as follows:

2018	$	15,213
2019	223
2020	237
2021	250
2022	35,263
Thereafter	5,598
	$	56,784