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Dividends (Narrative) (Details) - $ / shares			3 Months Ended		6 Months Ended
	Jan. 14, 2021	Oct. 15, 2020	Mar. 27, 2021	Mar. 28, 2020	Mar. 27, 2021	Mar. 28, 2020
Class A Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock			$ 0.165	$ 0.165	$ 0.33	$ 0.33
Class B Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock			$ 0.150	$ 0.150	$ 0.30	$ 0.30
Dividend I [Member]
Dividends Payable [Line Items]
Dividend payment date					Oct. 15, 2020
Dividend record date					Oct. 08, 2020
Dividend I [Member] | Class A Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock		$ 0.165
Dividend I [Member] | Class B Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock		$ 0.15
Dividend II [Member]
Dividends Payable [Line Items]
Dividend payment date					Jan. 14, 2021
Dividend record date					Jan. 07, 2021
Dividend II [Member] | Class A Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock	$ 0.165
Dividend II [Member] | Class B Common Stock [Member]
Dividends Payable [Line Items]
Cash dividends per share of common stock	$ 0.15

X

- Definition

Aggregate dividends paid during the period for each share of common stock outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

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Date the declared dividend will be paid, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=121583591&loc=d3e4304-108586

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