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Debt - Debt to Affiliates - Incremental Term Loan Facility (Details) - Deutsche Telekom AG - Affiliated Entity - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Short-term Debt [Line Items]
Issuance fees	$ 0	$ 0
LIBOR plus 1.50% Senior Secured Term Loan due 2022
Short-term Debt [Line Items]
Applicable margin, percentage			1.50%
Senior Secured Term Loans			$ 2,000,000,000.0
LIBOR plus 1.75% Senior Secured Term Loan due 2024
Short-term Debt [Line Items]
Applicable margin, percentage			1.75%
Senior Secured Term Loans			$ 2,000,000,000.0