0001553023 2020-10-06 2020-10-06 0001553023 cone:One450SeniorNotesDue2027Member cone:TheNASDAQStockMarketLLCMember 2020-10-06 2020-10-06 0001553023 us-gaap:CommonStockMember cone:TheNasdaqGlobalSelectMarketMember 2020-10-06 2020-10-06 false 0001553023 8-K 2020-10-06 CyrusOne Inc. MD 001-35789 46-0691837 2850 N. Harwood Street Suite 2200 Dallas TX 75201 972 350-0060 false false false false Common Stock, $0.01 par value CONE NASDAQ 1.450% Senior Notes due 2027 CONE27 NASDAQ false