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Stock-Based Compensation (Restricted Stock Units) (Details) - Restricted Stock Units (RSUs) [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jan. 04, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of RSU's granted (in dollars per share)	$ 58.69	$ 60.04	$ 53.57
Total fair value of RSU's granted	$ 2.3	$ 2.7	$ 2.1
Director [Member] | Non-Employee Director Equity Plan 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of restricted stock units granted to each non-employee director				4,259

X

- Definition

The number of restricted stock units granted to each grantee during the reporting period.

+ References

No definition available.

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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

+ 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 (d)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ 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)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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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.

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