Stockholders' Equity (Weighted Average Grant Date Fair Value of Options Granted) (Details) - $ / shares	12 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Stock-Based Compensation
Options granted, Weighted-Average Grant Date Fair Value Per Share	$ 24.98	$ 13.39	$ 17.02

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration