Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - Accounting Standards Update 2016-09 [Member] - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2017	Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings adjustment related to cumulative effect of new standard			$ 0.6
Excess tax benefit related to vested awards, effect on the provision for income taxes	$ (0.2)
Excess tax deficiency related to vested awards, effect on the provision for income taxes		$ 2.2

Employee Service Share Based Compensation,Tax Expense From Exercise of Stock Options

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- Definition

New Accounting Pronouncement Or Change In Accounting Principle, Effect on Retained Earnings

+ References

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- Definition

Amount of tax benefit from exercise of stock options granted under share-based compensation arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=SL79508275-113901

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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.

+ References

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