Stock Based Compensation Summary of Unvested RSUs (Details) - 2014 Equity Plan [Member] - Restricted Stock Units (RSUs) [Member] - $ / shares	Sep. 30, 2017	Mar. 15, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Unvested RSUs	6,658
Weighted Average Grant Date Fair Value	$ 37.31	$ 41.20
2015 Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Unvested RSUs	3,089
Weighted Average Grant Date Fair Value	$ 27.91
2016 Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Unvested RSUs	3,569
Weighted Average Grant Date Fair Value	$ 45.45

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=6415400&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.

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