COMMITMENTS AND CONTINGENCIES (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Contractual commitments under non-cancelable operating leases and purchase contracts

The following table summarizes our contractual commitments under non-cancelable operating leases and purchase contracts as of December 31, 2017:

	Operating Leases		Purchase Commitments
	($ in millions)
2018	$	87.9	$	692.7
2019	67.4		645.0
2020	51.5		631.5
2021	36.9		708.3
2022	23.9		708.0
Thereafter	87.5		4,364.2
Total commitments	$	355.1	$	7,749.7