XML 602 R123.htm IDEA: XBRL DOCUMENT v3.10.0.1
Financial risk management - Hedging activities (Details)
£ in Thousands, $ in Thousands
Jun. 30, 2018
USD ($)
Jun. 30, 2018
$ / £
Jun. 30, 2018
€ / £
Jun. 30, 2018
GBP (£)
Jun. 30, 2017
USD ($)
Jun. 30, 2017
$ / £
Jun. 30, 2017
€ / £
Jun. 30, 2017
GBP (£)
Jun. 30, 2016
$ / £
Jun. 30, 2016
€ / £
Jun. 30, 2016
GBP (£)
Financial risk management activities                      
Net debt | £       £ 253,746       £ 213,087     £ 260,898
Closing exchange rate   1.3194 1.1309     1.2988 1.1379   1.3332 1.2009  
US dollar                      
Financial risk management activities                      
Net debt $ 521,500       $ 524,700            
Hedged future USD revenues (307,019)       (299,533)            
Unhedged USD borrowings 214,481       225,167            
Borrowings | US dollar                      
Financial risk management activities                      
Net debt 650,000       650,000            
Cash and cash equivalents                      
Financial risk management activities                      
Net debt | £       £ (242,022)       £ (290,267)     £ (229,194)
Cash and cash equivalents | US dollar                      
Financial risk management activities                      
Net debt $ (128,500)       $ (125,300)