Public Utilities, Property, Plant and Equipment, Approved Composite Depreciation Rate for Plants in Service

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- Definition

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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- Definition

Composite depreciation rate for public utility plants in service.

+ References

No definition available.

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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.

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - PROPERTY PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands		12 Months Ended
	Oct. 01, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Public Utility, Property, Plant and Equipment [Line Items]
Composite rate of depreciation		2.25%	2.32%	2.31%
Depreciation and amortization		$ 81,841	$ 72,748	$ 61,399
Property Classifications
Total property, plant and equipment		3,211,070	2,955,130
Accumulated depreciation and amortization		(601,329)	(547,478)
Property, plant and equipment, net		2,609,741	2,407,652
Composite rate of depreciation	2.40%
Regulated Operation \| Distribution facilities
Property Classifications
Total property, plant and equipment		$ 1,952,697	1,823,672
Regulated Operation \| Distribution facilities \| Minimum
Property Classifications
Estimated Useful Lives		38 years
Regulated Operation \| Distribution facilities \| Maximum
Property Classifications
Estimated Useful Lives		74 years
Regulated Operation \| Transmission facilities
Property Classifications
Total property, plant and equipment		$ 294,586	292,433
Regulated Operation \| Transmission facilities \| Minimum
Property Classifications
Estimated Useful Lives		35 years
Regulated Operation \| Transmission facilities \| Maximum
Property Classifications
Estimated Useful Lives		56 years
Regulated Operation \| Storage facilities
Property Classifications
Total property, plant and equipment		$ 78,245	78,238
Regulated Operation \| Storage facilities \| Minimum
Property Classifications
Estimated Useful Lives		34 years
Regulated Operation \| Storage facilities \| Maximum
Property Classifications
Estimated Useful Lives		47 years
Unregulated Operation \| Solar property
Property Classifications
Total property, plant and equipment		$ 587,345	479,948
Unregulated Operation \| Solar property \| Minimum
Property Classifications
Estimated Useful Lives		20 years
Unregulated Operation \| Solar property \| Maximum
Property Classifications
Estimated Useful Lives		25 years
Unregulated Operation \| Wind property
Property Classifications
Estimated Useful Lives		25 years
Total property, plant and equipment		$ 244,764	228,644
Unregulated Operation \| All other property
Property Classifications
Total property, plant and equipment		$ 53,433	$ 52,195
Unregulated Operation \| All other property \| Minimum
Property Classifications
Estimated Useful Lives		5 years
Unregulated Operation \| All other property \| Maximum
Property Classifications
Estimated Useful Lives		35 years