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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

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- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

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Amount allocated to previously issued common shares repurchased by the issuing entity and held in treasury.

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- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

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Subsequent Events - Narrative (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions			3 Months Ended		6 Months Ended
	Mar. 28, 2018	Mar. 27, 2018	Feb. 24, 2018	Feb. 25, 2017	Feb. 24, 2018	Feb. 25, 2017
Subsequent Event
Subsequent Event [Line Items]
Repurchase of common stock, value		$ 146.0
Shares repurchased, average price per share (in dollars per share)		$ 124.00
Class B Common Stock
Subsequent Event [Line Items]
Quarterly dividend amount (in dollars per share)			$ 0.03	$ 0.03	$ 0.06	$ 0.06
Class B Common Stock \| Subsequent Event
Subsequent Event [Line Items]
Shares repurchased (in shares)		1,105
Quarterly dividend amount (in dollars per share)	$ 0.09
Common Stock
Subsequent Event [Line Items]
Quarterly dividend amount (in dollars per share)			$ 0.0375	$ 0.0375	$ 0.075	$ 0.075
Common Stock \| Subsequent Event
Subsequent Event [Line Items]
Shares repurchased (in shares)		73
Quarterly dividend amount (in dollars per share)	$ 0.1125