Condensed Consolidating Financial Information (Details)	12 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2013
Long-term debt
Ownership percentage in guarantor subsidiaries	100.00%
7.25% Senior notes, due January 2019
Long-term debt
Interest rate on long-term debt (as a percent)	7.25%	7.25%	7.25%

Contractual interest rate for funds borrowed, under the debt agreement.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant