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Share-Based Compensation - Narrative (Details) $ / shares in Units, shares in Millions, $ in Millions	9 Months Ended
	Sep. 23, 2020 USD ($) $ / shares shares
Certain Employee
Restricted Stock Units
Unrecognized compensation cost related to unvested share awards outstanding | $	$ 9.8
Unrecognized compensation cost, expected weighted average period	1 year 6 months
Board Members
Restricted Stock Units
Restricted stock units converted into shares of common stock (less than, in shares)	0.1
Restricted Stock Units for Board Members | Certain Employee
Restricted Stock Units
Grants in periods (less than, in shares)	0.8
Fair value of units granted (in dollars per share) | $ / shares	$ 10.46
Period of performance	2 years
Restricted Stock Units for Board Members | Board Members
Restricted Stock Units
Grants in periods (less than, in shares)	0.1
Fair value of units granted (in dollars per share) | $ / shares	$ 10.46
Period of performance	1 year
Unrecognized compensation cost related to unvested share awards outstanding | $	$ 0.6
Unrecognized compensation cost, expected weighted average period	8 months 12 days
Performance Shares | Certain Employee
Restricted Stock Units
Common stock, shares issued (in shares)	0.3
Shares paid for tax withholding (in shares)	0.2

X

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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-Publisher FASB
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-Topic 718
-SubTopic 10
-Section 50
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- Definition

Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

Number of non-option equity instruments exercised by participants.

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Number of shares issued under share-based payment arrangement.

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- Definition

Number of shares used to settle grantee's tax withholding obligation for award under share-based payment arrangement.

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