Summary of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) customer vote shares	Dec. 31, 2022 USD ($) customer shares	Dec. 31, 2021 USD ($) shares
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Advertising costs	$ 241,500,000	$ 379,000,000	$ 383,000,000
Foreign currency transaction gains (losses)	$ 8,400,000	$ (1,200,000)	$ 12,200,000
Threshold period for write-off of capitalized development costs	3 years
Antidilutive securities excluded from EPS | shares	500,000	800,000	400,000
Repurchase amount (up to)	$ 1,500,000,000
Available for repurchase under program	$ 135,300,000
Accounts Receivable | Customer Concentration Risk
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of customers | customer	1	2
Accounts Receivable | Customer Concentration Risk | Customer One
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Concentration risk, percentage	15.00%	14.00%
Accounts Receivable | Customer Concentration Risk | Customer Two
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Concentration risk, percentage		12.00%
Class A  Common Stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Common stock, voting rights | vote	1
Common stock, conversion ratio	1
Stockholders entitled election of Board of Directors	25.00%
Share repurchases | shares	0	0
Class B  Common Stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Common stock, voting rights | vote	10
Common stock, conversion ratio	1
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Period of related affiliation arrangement (up to)	6 years
Prepaid expenses and other current assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax receivable, program rights	$ 230,300,000	$ 143,100,000
Other Noncurrent Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax receivable, program rights	$ 49,900,000	$ 104,500,000
2011 Non-Employee Director Plan | Restricted stock units
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Vesting percentage	100.00%