Discontinued Operations (Details) - Jan. 10, 2018 £ in Millions, $ in Millions	GBP (£)	USD ($)
Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from sale of business	£ 37	$ 50

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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