Intangible Assets Subject to Amortization (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 330,099	$ 328,769
Accum. Amortization	234,670	227,986
Net	95,429us-gaap_FiniteLivedIntangibleAssetsNet	100,783us-gaap_FiniteLivedIntangibleAssetsNet
Customer Lists
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	305,892	304,699
Accum. Amortization	230,267	224,215
Net	75,625	80,484
Trade Names And Other Intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	24,207	24,070
Accum. Amortization	4,403	3,771
Net	$ 19,804	$ 20,299

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=sgu_TradeNamesAndOtherIntangiblesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerListsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: