Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2012

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Rental Payments for Operating Leases

At December 31, 2012, future minimum rental payments under non-cancelable operating leases were:

Year	($ in millions)
2013	$	9.1
2014	8.4
2015	7.1
2016	5.6
2017	4.4
Thereafter	18.5
Total	$	53.1