Quarterly report pursuant to Section 13 or 15(d)

Credit facilities - Schedule of Minimum Maturities (Details)

v3.10.0.1
Credit facilities - Schedule of Minimum Maturities (Details) - USD ($)
$ in Millions
Sep. 30, 2018
Dec. 31, 2017
Line of Credit Facility [Line Items]    
Total debt $ 1,096 $ 1,211
Senior Secured Revolving Credit Facility [Member]    
Line of Credit Facility [Line Items]    
October 1, 2018 to December 31, 2018 14  
2019 10  
2020 8  
2021 31  
Total debt $ 63