Unaudited Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
ASSETS
Cash and cash equivalents	$ 70,070	$ 95,390	$ 96,870
Accounts receivable, net	74,788	120,789	90,240
Accounts receivable from affiliates	32,247	32,636	27,642
Inventories, net	193,913	184,445	162,234
Deferred income taxes	10,721	14,452	10,604
Prepaid expenses and other	21,498	13,578	19,272
Total current assets	403,237	461,290	406,862
Property, plant and equipment, net	245,858	219,256	184,062
Coal supply agreements and other intangibles, net	58,920	59,685	68,711
Other non-current assets	71,985	69,725	54,093
Total assets	780,000	809,956	713,728
LIABILITIES AND EQUITY
Accounts payable	103,642	133,016	90,576
Revolving credit agreements of subsidiaries - not guaranteed by the parent company	47,364	23,460	42,754
Current maturities of long-term debt of subsidiaries - not guaranteed by the parent company	7,868	7,859	6,965
Accrued payroll	10,351	29,030	13,590
Other current liabilities	32,836	44,754	27,366
Total current liabilities	202,061	238,119	181,251
Long-term debt of subsidiaries - not guaranteed by the parent company	168,069	152,431	123,839
Mine closing reserves	29,878	29,764	29,223
Pension and other postretirement obligations	7,409	7,648	15,142
Long-term deferred income taxes	22,918	24,786	24,632
Other long-term liabilities	60,122	59,428	59,148
Total liabilities	490,457	512,176	433,235
Common stock:
Capital in excess of par value	0	941	20,035
Retained earnings	294,183	301,227	272,547
Accumulated other comprehensive loss	(12,439)	(12,259)	(20,427)
Total stockholders' equity	289,543	297,780	280,493
Total liabilities and equity	780,000	809,956	713,728
Common Class A
Common stock:
Common stock	6,218	6,290	6,756
Common Class B
Common stock:
Common stock	$ 1,581	$ 1,581	$ 1,582