Stock-Based Compensation - Schedule of Restricted Shares and Performance Stock Units (Details) - $ / shares shares in Millions	Dec. 31, 2017	Jan. 01, 2017
Restricted shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Quantity	1.3	1.1
Weighted average fair value per award (USD per award)	$ 52.58	$ 44.85
Performance stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Quantity	0.5	0.2
Weighted average fair value per award (USD per award)	$ 48.99	$ 42.65

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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