XML 64 R51.htm IDEA: XBRL DOCUMENT v3.7.0.1
Property, Plant, Equipment and Mine Development (Tables)
 12 Months Ended
Dec. 31, 2016
Property, Plant, Equipment and Mine Development [Abstract]  
Property, Plant and Equipment [Table Text Block]
Property, plant, equipment and mine development, net, as of December 31, 2016 and December 31, 2015 consisted of the following:
 
December 31,
 
2016
 
2015
 
(Dollars in millions)
Land and coal interests
$
10,330.8

 
$
10,503.7

Buildings and improvements
1,507.6

 
1,506.0

Machinery and equipment
2,130.2

 
2,280.4

Less: Accumulated depreciation, depletion and amortization
(5,191.9
)
 
(5,031.6
)
Total, net
$
8,776.7

 
$
9,258.5