Operating Expenses - Additional Information (Detail) - GBP (£) £ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Operating expense [line items] | |||
| Research and efficacy costs | £ 14 | £ 23 | £ 33 |
| Restructuring costs | 79 | 329 | 35 |
| Non-audit fees amounts related to audits for disposals | 1 | 1 | 1 |
| Penguin Random House [member] | |||
| Operating expense [line items] | |||
| Service fee income | 3 | 4 | 16 |
| Restructuring costs | £ 0 | £ 9 | £ 12 |