XML 155 R118.htm IDEA: XBRL DOCUMENT v3.19.1
Deferred tax - Movements of Major Gross Deferred Tax Assets (Detail) - GBP (£)
£ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Beginning balance [1] £ 160.3  
Ending balance 153.0 £ 160.3 [1]
Gross deferred tax assets [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Beginning balance 411.8 598.0
Acquisition of subsidiaries 2.0 2.6
(Charge)/credit to income (16.6) (60.2)
Impact of US tax reform   (62.1)
Charge to other comprehensive income (0.2) (20.9)
Charge to equity (1.6) (27.3)
Exchange differences 16.6 (18.3)
Ending balance 412.0 411.8
Gross deferred tax assets [member] | Deferred compensation [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Beginning balance 53.5 95.6
(Charge)/credit to income 4.7 (5.5)
Impact of US tax reform   (30.8)
Exchange differences 3.4 (5.8)
Ending balance 61.6 53.5
Gross deferred tax assets [member] | Accounting provisions and accruals [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Beginning balance 84.9 80.6
(Charge)/credit to income 13.0 6.6
Impact of US tax reform   (8.1)
Exchange differences 3.5 5.8
Ending balance 101.4 84.9
Gross deferred tax assets [member] | Retirement benefit obligation [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Beginning balance 75.6 141.4
(Charge)/credit to income (11.2) (10.2)
Impact of US tax reform   (29.1)
Charge to other comprehensive income (0.2) (20.9)
Exchange differences 4.3 (5.6)
Ending balance 68.5 75.6
Gross deferred tax assets [member] | Property, plant and equipment [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Beginning balance 68.4 70.8
(Charge)/credit to income (20.6) 6.9
Impact of US tax reform   (6.8)
Exchange differences 0.1 (2.5)
Ending balance 47.9 68.4
Gross deferred tax assets [member] | Tax losses and credits [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Beginning balance 72.7 89.7
(Charge)/credit to income (8.9) (34.4)
Impact of US tax reform   23.1
Exchange differences 3.3 (5.7)
Ending balance 67.1 72.7
Gross deferred tax assets [member] | Share-based payments [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Beginning balance 33.0 75.8
(Charge)/credit to income (15.3) (0.4)
Impact of US tax reform   (10.9)
Charge to equity (1.6) (27.3)
Exchange differences 0.7 (4.2)
Ending balance 16.8 33.0
Gross deferred tax assets [member] | Restructuring provisions [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Beginning balance 5.8 5.9
(Charge)/credit to income 10.7 (1.5)
Impact of US tax reform   1.6
Exchange differences 0.8 (0.2)
Ending balance 17.3 5.8
Gross deferred tax assets [member] | Other temporary differences [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Beginning balance 17.9 38.2
Acquisition of subsidiaries 2.0 2.6
(Charge)/credit to income 11.0 (21.7)
Impact of US tax reform   (1.1)
Exchange differences 0.5 (0.1)
Ending balance £ 31.4 £ 17.9
[1] Prior year figures have been restated for the impact of the adoption of IFRS 15 Revenue from Contracts with Customers, as described in the accounting policies.