Dividend (Detail) (USD $)	0 Months Ended	12 Months Ended
Aug. 06, 2014	May 14, 2014	Feb. 11, 2014	Dec. 17, 2013	Aug. 07, 2013	May 08, 2013	Dec. 10, 2012	Sep. 30, 2014	Sep. 30, 2013
Stockholders' Equity Note [Abstract]
Common Stock, Dividends, Per Share, Declared	$ 0.11	$ 0.11	$ 0.11	$ 0.10	$ 0.10	$ 0.10	$ 0.20	$ 0.43	$ 0.40

Aggregate dividends declared during the period for each share of common stock outstanding.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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