Supplemental Financial Information (Noncash Activities) (Details) - USD ($) $ / shares in Units, $ in Billions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Supplemental Financial Information [Line Items]
Property and equipment and intangible assets accrued but not yet paid	$ 1.5	$ 1.8
Dividends payable	$ 1.2	$ 1.1
Dividends payable (in dollars per share)	$ 0.25	$ 0.23
Universal Beijing Resort [Member]
Supplemental Financial Information [Line Items]
Operating lease assets and liabilities recognized	$ 2.8
Lease terms	33 years
Weighted average discount rate on operating lease	4.40%