Long-Term Debt	3 Months Ended
Mar. 31, 2017
Debt Instrument [Line Items]
Long-Term Debt	Long-Term Debt As of March 31, 2017, our debt had a carrying value of $61.8 billion and an estimated fair value of $66.7 billion. The estimated fair value of our publicly traded debt was primarily based on Level 1 inputs that use quoted market values for the debt. The estimated fair value of debt for which there are no quoted market prices was based on Level 2 inputs that use interest rates available to us for debt with similar terms and remaining maturities. Debt Borrowings and Repayments In March 2017, we issued $1.005 billion aggregate principal amount of 4.45% senior notes due 2047. In January 2017, we issued $1.25 billion aggregate principal amount of 3.00% senior notes due 2024 and $1.25 billion aggregate principal amount of 3.30% senior notes due 2027. In January 2017, we repaid at maturity $1.0 billion aggregate principal amount of 6.50% senior notes due 2017. Revolving Credit Facilities As of March 31, 2017, amounts available under our consolidated revolving credit facilities, net of amounts outstanding under our commercial paper programs and outstanding letters of credit, totaled $7.4 billion, which included $585 million available under NBCUniversal Enterprise’s revolving credit facility. Commercial Paper Programs As of March 31, 2017, NBCUniversal Enterprise had $915 million face amount of commercial paper outstanding. Comcast had no commercial paper outstanding.
NBCUniversal Media LLC [Member]
Debt Instrument [Line Items]
Long-Term Debt	Long-Term Debt As of March 31, 2017, our debt, excluding the note payable to Comcast, had a carrying value of $11.7 billion and an estimated fair value of $12.6 billion. The estimated fair value of our publicly traded debt was primarily based on Level 1 inputs that use quoted market values for the debt. The estimated fair value of debt for which there are no quoted market prices was based on Level 2 inputs that use interest rates available to us for debt with similar terms and remaining maturities. Cross-Guarantee Structure We, Comcast and a 100% owned cable holding company subsidiary of Comcast (“CCCL Parent”) have fully and unconditionally guaranteed each other’s debt securities, including the $7 billion Comcast revolving credit facility due 2021. As of March 31, 2017, outstanding debt securities of $45.5 billion of Comcast and CCCL Parent were subject to the guarantee structure. We do not, however, guarantee the obligations of NBCUniversal Enterprise with respect to its $3.3 billion aggregate principal amount of senior notes, $1.5 billion revolving credit facility, commercial paper program, or $725 million liquidation preference of Series A cumulative preferred stock. None of Comcast, CCCL Parent nor NBCUniversal guarantee the $3.4 billion of Universal Studios Japan term loans.

Long-Term Debt

3 Months Ended

Mar. 31, 2017

As of March 31, 2017, our debt had a carrying value of $61.8 billion and an estimated fair value of $66.7 billion. The estimated fair value of our publicly traded debt was primarily based on Level 1 inputs that use quoted market values for the debt. The estimated fair value of debt for which there are no quoted market prices was based on Level 2 inputs that use interest rates available to us for debt with similar terms and remaining maturities.

Debt Borrowings and Repayments

In March 2017, we issued $1.005 billion aggregate principal amount of 4.45% senior notes due 2047. In January 2017, we issued $1.25 billion aggregate principal amount of 3.00% senior notes due 2024 and $1.25 billion aggregate principal amount of 3.30% senior notes due 2027.

In January 2017, we repaid at maturity $1.0 billion aggregate principal amount of 6.50% senior notes due 2017.

Revolving Credit Facilities

As of March 31, 2017, amounts available under our consolidated revolving credit facilities, net of amounts outstanding under our commercial paper programs and outstanding letters of credit, totaled $7.4 billion, which included $585 million available under NBCUniversal Enterprise’s revolving credit facility.

Commercial Paper Programs

As of March 31, 2017, NBCUniversal Enterprise had $915 million face amount of commercial paper outstanding. Comcast had no commercial paper outstanding.

NBCUniversal Media LLC [Member]

Debt Instrument [Line Items]

Long-Term Debt

As of March 31, 2017, our debt, excluding the note payable to Comcast, had a carrying value of $11.7 billion and an estimated fair value of $12.6 billion. The estimated fair value of our publicly traded debt was primarily based on Level 1 inputs that use quoted market values for the debt. The estimated fair value of debt for which there are no quoted market prices was based on Level 2 inputs that use interest rates available to us for debt with similar terms and remaining maturities.

Cross-Guarantee Structure

We, Comcast and a 100% owned cable holding company subsidiary of Comcast (“CCCL Parent”) have fully and unconditionally guaranteed each other’s debt securities, including the $7 billion Comcast revolving credit facility due 2021. As of March 31, 2017, outstanding debt securities of $45.5 billion of Comcast and CCCL Parent were subject to the guarantee structure.

We do not, however, guarantee the obligations of NBCUniversal Enterprise with respect to its $3.3 billion aggregate principal amount of senior notes, $1.5 billion revolving credit facility, commercial paper program, or $725 million liquidation preference of Series A cumulative preferred stock.

None of Comcast, CCCL Parent nor NBCUniversal guarantee the $3.4 billion of Universal Studios Japan term loans.