Shareholders' Equity - Summary of Range of Exercise Prices and Weighted-Average Exercise Prices for Options Outstanding (Details) shares in Millions	12 Months Ended
Dec. 31, 2017 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Outstanding (in shares) \| shares	0.4
Fiscal 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, Minimum (in USD per share)	$ 20.48
Range of Exercise Prices, Maximum (in USD per share)	$ 23.06
Stock Options Outstanding (in shares) \| shares	0.2
Weighted Average Exercise Price (in USD per share)	$ 23.03
Weighted Average Remaining Contractual Life	4 years 2 months 12 days
Fiscal 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, Average (in USD per share)	$ 18.01
Stock Options Outstanding (in shares) \| shares	0.2
Weighted Average Exercise Price (in USD per share)	$ 18.01
Weighted Average Remaining Contractual Life	5 years 7 months 6 days

Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Average Range Limit

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- Definition

Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Outstanding Options Weighted Average Exercise Price

+ References

No definition available.

+ Details

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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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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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

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- Definition

The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ References

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)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

+ Details

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- Definition

Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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

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