Income Taxes (Expected Income Tax) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Expected amount	$ 9,653	$ 3,745	$ 10,359
Change in Indiana rate	(85)	(1,407)
State income taxes, net of federal benefit	612	186	877
Percentage depletion	(2,606)	(1,996)	(3,826)
Stock-based compensation		343
Captive insurance	(419)	(419)	(419)
Other	283	30	184
Total tax expected	$ 7,438	$ 482	$ 7,175