Fair Value Measurements and Derivative Instruments (Fair Value of Long-term Debt) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair Value, Inputs, Level 1 [Member]
Long-Term Debt, Fair Value [Line Items]
Long-term debt	$ 14,597	$ 14,251
Fair Value, Inputs, Level 1 [Member] | Carrying Amount [Member]
Long-Term Debt, Fair Value [Line Items]
Long-term debt	13,600	13,600
Fair Value, Inputs, Level 2 [Member] | Deutsche Telekom [Member]
Long-Term Debt, Fair Value [Line Items]
Long-term debt	6,025	5,866
Fair Value, Inputs, Level 2 [Member] | Carrying Amount [Member] | Deutsche Telekom [Member]
Long-Term Debt, Fair Value [Line Items]
Long-term debt	$ 5,600	$ 5,600