Revenue Recognition (Schedule of Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 24, 2021	Sep. 25, 2020	Sep. 27, 2019
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 1,281,256	$ 1,161,792	$ 1,241,620
Revenue from contract with customer, percent	100.00%	100.00%	100.00%
United States
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 419,901	$ 460,972
Revenue from contract with customer, percent	33.00%	40.00%	36.00%
International
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 861,355	$ 700,820
Revenue from contract with customer, percent	67.00%	60.00%	64.00%
Licensing
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 1,214,147	$ 1,078,577	$ 1,107,280
Revenue from contract with customer, percent	95.00%	93.00%	89.00%
Revenue from contract with customer, licensing percent	100.00%	100.00%	100.00%
Products and services
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 67,109	$ 83,215	$ 134,340
Revenue from contract with customer, percent	5.00%	7.00%	11.00%
Broadcast
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 475,648	$ 439,415	$ 474,147
Revenue from contract with customer, licensing percent	39.00%	41.00%	43.00%
Mobile
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 261,232	$ 226,972	$ 193,052
Revenue from contract with customer, licensing percent	22.00%	21.00%	17.00%
CE
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 181,944	$ 152,608	$ 154,399
Revenue from contract with customer, licensing percent	15.00%	14.00%	14.00%
PC
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 141,919	$ 132,302	$ 113,597
Revenue from contract with customer, licensing percent	12.00%	12.00%	10.00%
Other
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 153,404	$ 127,280	$ 172,085
Revenue from contract with customer, licensing percent	12.00%	12.00%	16.00%