Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2014

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Commitments for Operating Leases and Long-Term Purchase Obligations

As of December 31, 2014, future minimum commitments for operating leases and long-term purchase obligations for the years ending December 31 are as follows:

	Operating Leases		Long-Term Purchase Obligations
	(Dollars in millions)
2015	$	55.5	$	314.4
2016	49.8		244.1
2017	38.2		110.8
2018	26.1		77.6
2019	21.3		—
Thereafter	46.5		—
Total minimum commitments	$	237.4	$	746.9