Operating Leases (Tables)

12 Months Ended

Dec. 31, 2011

Leases [Abstract]

Schedule Of Future Commitments Under Non Cancelable Operating Leases

As of December 31, 2011, the company's total future commitments by year under non-cancelable operating leases are as follows:

$ in millions	Total	Buildings	Other
2012	69.4	65.0	4.4
2013	67.0	62.7	4.3
2014	66.1	61.9	4.2
2015	66.9	63.5	3.4
2016	60.1	58.3	1.8
Thereafter	288.5	285.8	2.7
Gross lease commitments	618.0	597.2	20.8
Less: future minimum payments expected to be received under non-cancelable subleases	84.2	84.2	—
Net lease commitments	533.8	513.0	20.8