Represents the amount available for issuance of debt securities under a Registration Statement filed with the SEC.

No definition available.

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Balance Type:	credit
Period Type:	duration

- Definition

Represents the additional spread on premium based on the difference between cost of funds on the date of purchase and the date of redemption, expressed as a percentage.

+ References

No definition available.

+ Details

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Namespace Prefix:	awr_
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Balance Type:	na
Period Type:	duration

- Definition

Represents the interest coverage ratio required to be maintained for debt instrument.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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- Definition

Debt Instrument Redemption Premium above Treasury Yield

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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Period Type:	duration

- Definition

Represents the redemption premium as a percentage of the par value of debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	awr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the redemption premium as a percentage of the par value of debt instrument after the specified period.

+ References

No definition available.

+ Details

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Namespace Prefix:	awr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the redemption price of the debt instrument as a percentage of the principal amount.

+ References

No definition available.

+ Details

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Namespace Prefix:	awr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Ratio of Indebtedness to EBITDA

+ References

No definition available.

+ Details

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Namespace Prefix:	awr_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

+ Details

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

- Definition

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

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: 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

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

Name:	us-gaap_ExtinguishmentOfDebtAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Indebtedness divided by net capital.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Details

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- Details

Name:	us-gaap_CreditFacilityAxis=awr_PrivatePlacementNotesMember
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- Details

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- Details

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Long-Term Debt (Details) (USD $)	0 Months Ended	12 Months Ended
Long-Term Debt (Details) (USD $)	Jul. 16, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 23, 2014	Mar. 31, 2014
GSWC
Long-term debt
Ratio of Indebtedness to Net Capital		0.4367
Ratio of Indebtedness to EBITDA		2.3695
Redemption price of debt instrument, as a percentage of principal amount	100.00%
Amount available for issuance of debt securities		$ 100,000,000.0
GSWC \| Maximum
Long-term debt
Ratio of Indebtedness to Net Capital		0.6667
Ratio of Indebtedness to EBITDA		8.0000
Private Placement Notes [Member] \| GSWC
Long-term debt
Interest coverage ratio		400.00%
Private Placement Notes [Member] \| GSWC \| Minimum
Long-term debt
Interest coverage ratio		200.00%
Private placement notes
Long-term debt
Interest rate (as a percent)		9.56%	9.56%
Private placement notes \| GSWC
Long-term debt
Face amount of debt		28,000,000
Interest rate (as a percent)		9.56%	9.56%
Debt Instrument Redemption Premium above Treasury Yield		5500.00%
Private placement notes \| GSWC \| Maximum
Long-term debt
Redemption premium after 2021 (as a percent)		3.00%
Debt issues other than 9.56% Notes and Senior Notes issued to Co-Bank \| GSWC \| Maximum
Long-term debt
Redemption premium (as a percent)		0.383%
Senior Notes issued to Co-Bank \| GSWC
Long-term debt
Additional spread on premium (as a percent)		0.50%
American Recovery and Reinvestment Act Obligation due 2033 \| GSWC
Long-term debt
Interest rate (as a percent)		2.50%
Notes Payable 3.45 Percent Due 2029 [Member]
Long-term debt
Interest rate (as a percent)		3.45%	3.45%
Notes Payable 3.45 Percent Due 2029 [Member] \| GSWC
Long-term debt
Face amount of debt				15,000,000
Interest rate (as a percent)		3.45%	3.45%		3.45%
Notes Payable 6.87 Percent Due 2023 [Member]
Long-term debt
Interest rate (as a percent)		6.87%	6.87%
Notes Payable 6.87 Percent Due 2023 [Member] \| GSWC
Long-term debt
Principal amount of notes redeemed	5,000,000
Interest rate (as a percent)		6.87%	6.87%
Notes Payable 7 Percent Due 2023 [Member]
Long-term debt
Interest rate (as a percent)		7.00%	7.00%
Notes Payable 7 Percent Due 2023 [Member] \| GSWC
Long-term debt
Principal amount of notes redeemed	10,000,000
Interest rate (as a percent)		7.00%	7.00%