Revenue Recognition (Schedule of Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 01, 2022	Mar. 26, 2021	Apr. 01, 2022	Mar. 26, 2021
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 334,371	$ 319,558	$ 686,004	$ 709,432
Revenue from contract with customer, percent	100.00%	100.00%	100.00%	100.00%
United States
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 173,287	$ 153,267	$ 297,209	$ 254,341
Revenue from contract with customer, percent	52.00%	48.00%	43.00%	36.00%
International
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 161,084	$ 166,291	$ 388,795	$ 455,091
Revenue from contract with customer, percent	48.00%	52.00%	57.00%	64.00%
Licensing
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 313,833	$ 303,585	$ 646,117	$ 676,590
Revenue from contract with customer, licensing percent	100.00%	100.00%	100.00%	100.00%
Revenue from contract with customer, percent	94.00%	95.00%	94.00%	95.00%
Products and services
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 20,538	$ 15,973	$ 39,887	$ 32,842
Revenue from contract with customer, percent	6.00%	5.00%	6.00%	5.00%
Broadcast
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 104,481	$ 104,813	$ 226,114	$ 244,113
Revenue from contract with customer, licensing percent	33.00%	35.00%	35.00%	36.00%
PC
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 57,466	$ 51,104	$ 92,243	$ 83,839
Revenue from contract with customer, licensing percent	18.00%	17.00%	14.00%	12.00%
Mobile
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 66,055	$ 65,673	$ 140,975	$ 171,296
Revenue from contract with customer, licensing percent	21.00%	22.00%	22.00%	25.00%
CE
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 53,956	$ 48,284	$ 111,529	$ 100,205
Revenue from contract with customer, licensing percent	17.00%	16.00%	17.00%	15.00%
Other
Revenue from External Customer [Line Items]
Revenue from contract with customer	$ 31,875	$ 33,711	$ 75,256	$ 77,137
Revenue from contract with customer, licensing percent	11.00%	10.00%	12.00%	12.00%