Significant Transactions	6 Months Ended
Significant Transactions	Jun. 30, 2018
Business Acquisition [Line Items]
Significant Transactions	Significant Transactions Sky Offer On July 11, 2018, we announced an increased cash offer for the entire issued and to be issued share capital of Sky plc, which was recommended by the Sky Independent Committee. Pursuant to the increased offer, Sky shareholders will be entitled to receive £14.75 in cash for each Sky share (implying a value of approximately £26 billion, or $34 billion using the exchange rate at the time of the announcement of the increased offer, for the fully diluted share capital of Sky). If our offer is successful, completion is expected to occur before the usual date for declaration and payment of the final dividend for Sky’s fiscal year ended June 30, 2018, so the increased offer price includes an amount in lieu of any such dividend. The offer is subject to the satisfaction (or waiver, where applicable) of certain conditions, including receipt of antitrust and regulatory approvals and securing acceptances carrying more than 50% of the voting rights then normally exercisable at a general meeting of Sky. We have already received relevant regulatory approvals in the European Union, Austria, Germany, Italy and Jersey. We expect to complete the acquisition of Sky before the end of October 2018 if these conditions are satisfied or waived, as applicable. In connection with our offer, the original terms of which were announced on April 25, 2018, we have entered into an unsecured bridge credit agreement in an aggregate principal amount of up to £16 billion and an unsecured term loan credit agreement in an aggregate principal amount of up to £7 billion ($22 billion and $10 billion, respectively, using the exchange rate at the time of announcement of the original terms of the offer), which will be guaranteed by Comcast Cable Communications, LLC and NBCUniversal. In addition, proceeds from borrowings under our existing $7 billion revolving credit facility are available to finance the cash consideration payable under the offer. Universal Beijing Resort We entered into an agreement with a consortium of Chinese state-owned companies to build and operate a Universal theme park and resort in Beijing, China (“Universal Beijing Resort”). We own a 30% interest in Universal Beijing Resort and the construction will be funded through a combination of debt financing and equity contributions from the investors in accordance with their equity interests. The debt financing, which is being provided by a syndicate of Chinese financial institutions, contains certain financial and operating covenants and a maximum borrowing limit of ¥26.6 billion RMB (approximately $4 billion as of quarter end). The debt financing is secured by the assets of Universal Beijing Resort and the equity interests of the investors. In June 2018, Universal Beijing Resort borrowed $235 million of term loans under the debt financing agreements. We have concluded that Universal Beijing Resort is a variable interest entity based on its governance structure, and we consolidate it because we have the power to direct activities that most significantly impact its economic performance. There are no liquidity arrangements, guarantees or other financial commitments between us and Universal Beijing Resort, and therefore our maximum risk of financial loss is our 30% interest. Universal Beijing Resort’s results of operations are reported in our Theme Parks segment. Our condensed consolidated statement of cash flows includes the costs of construction and related borrowings in the "construction of Universal Beijing Resort" and "proceeds from borrowings" captions, respectively, and equity contributions from our investing partner are included in other financing activities. In March 2018, Universal Beijing Resort received initial equity investments through a combination of cash and noncash contributions from the investors. As of June 30, 2018, our condensed consolidated balance sheet included assets, primarily property and equipment, and liabilities, including the term loans, of Universal Beijing Resort totaling $1.2 billion and $587 million, respectively. Universal Studios Japan On April 6, 2017, we acquired the remaining interests in Universal Studios Japan that we did not already own for $2.3 billion. The acquisition was funded through cash on hand and borrowings under our commercial paper program. Because we maintained control of Universal Studios Japan, the difference between the consideration transferred and the recorded value of the noncontrolling interests, as well as the related tax and accumulated other comprehensive income impacts, were recorded to additional paid-in capital.
NBCUniversal Media LLC [Member]
Business Acquisition [Line Items]
Significant Transactions	Significant Transactions Universal Beijing Resort We entered into an agreement with a consortium of Chinese state-owned companies to build and operate a Universal theme park and resort in Beijing, China (“Universal Beijing Resort”). We own a 30% interest in Universal Beijing Resort and the construction will be funded through a combination of debt financing and equity contributions from the investors in accordance with their equity interests. The debt financing, which is being provided by a syndicate of Chinese financial institutions, contains certain financial and operating covenants and a maximum borrowing limit of ¥26.6 billion RMB (approximately $4 billion as of quarter end). The debt financing is secured by the assets of Universal Beijing Resort and the equity interests of the investors. In June 2018, Universal Beijing Resort borrowed $235 million of term loans under the debt financing agreements. We have concluded that Universal Beijing Resort is a variable interest entity based on its governance structure, and we consolidate it because we have the power to direct activities that most significantly impact its economic performance. There are no liquidity arrangements, guarantees or other financial commitments between us and Universal Beijing Resort, and therefore our maximum risk of financial loss is our 30% interest. Universal Beijing Resort’s results of operations are reported in our Theme Parks segment. Our condensed consolidated statement of cash flows includes the costs of construction and related borrowings in the "construction of Universal Beijing Resort" and "proceeds from borrowings" captions, respectively, and equity contributions from our investing partner are included in other financing activities. In March 2018, Universal Beijing Resort received initial equity investments through a combination of cash and noncash contributions from the investors. As of June 30, 2018, our condensed consolidated balance sheet included assets, primarily property and equipment, and liabilities, including the term loans, of Universal Beijing Resort totaling $1.2 billion and $587 million, respectively. Universal Studios Japan On April 6, 2017, we acquired the remaining interests in Universal Studios Japan that we did not already own for $2.3 billion. The acquisition was funded through borrowings under our revolving credit agreement with Comcast. Because we maintained control of Universal Studios Japan, the difference between the consideration transferred and the recorded value of the noncontrolling interests, as well as the related accumulated other comprehensive income impact, were recorded to member's capital.