XML 36 R23.htm IDEA: XBRL DOCUMENT v3.7.0.1
Inventories (Details) - USD ($)
$ in Thousands
Jun. 30, 2017
Dec. 31, 2016
Jun. 30, 2016
Inventory Disclosure [Abstract]      
Coal - NACoal $ 12,653 $ 13,137 $ 18,533
Mining supplies - NACoal 15,709 15,790 19,868
Total inventories at weighted average cost 28,362 28,927 38,401
Sourced inventories - HBB 104,342 95,008 96,401
Retail inventories - KC 31,055 33,407 32,787
Total inventories $ 163,759 $ 157,342 $ 167,589