Leases Leases (Tables)

12 Months Ended

Dec. 31, 2016

Operating Leased Assets [Line Items]

Leases And Royalty Future Minimum Payments [Table Text Block]

Future minimum lease and royalty payments as of December 31, 2016 are as follows:

	Capital Leases		Operating Leases		Coal Lease and Royalty Obligations
Year Ending December 31,
	(Dollars in millions)
2017	$	7.3	$	148.7	$	6.1
2018	8.9		100.4		5.7
2019	0.5		60.2		5.2
2020	0.5		26.4		4.9
2021	0.5		10.6		5.3
2022 and thereafter	9.6		26.6		26.6
Total minimum lease payments	27.3		$	372.9	$	53.8
Less interest	7.6
Present value of minimum capital lease payments	$	19.7