Represents the number of stock incentive plans of the entity.

No definition available.

Name:	awr_NumberOfStockIncentivePlans
Namespace Prefix:	awr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the annual retainer multiplier used in determining awards.

+ References

No definition available.

+ Details

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

- Definition

Period in which 33% vesting rights is earned by awardeed of the grant, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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

- Definition

Represents the common stock entitled to be received under each share-based payment award.

+ References

No definition available.

+ Details

Name:	awr_ShareBasedCompensationArrangementByShareBasedPaymentAwardCommonStockEntitledToBeReceivedUnderEachAward
Namespace Prefix:	awr_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The period of time, from the grant date until the time at which the share-based [option] award expires.

+ References

No definition available.

+ Details

Name:	awr_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationTerm
Namespace Prefix:	awr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, expressed as a percentage.

+ References

No definition available.

+ Details

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

- Definition

Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in the third year from the date of grant, thereby giving the employee the legal right to convert the award to shares, expressed as a percentage.

+ References

No definition available.

+ Details

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

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

-URI http://asc.fasb.org/extlink&oid=6793087&loc=d3e301413-122809

+ Details

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

- Definition

Represents the compensation cost capitalized during the period arising from equity-based compensation arrangements (for example, shares of stock, units, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

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

Stock-Based Compensation Plans (Details) (USD $)	12 Months Ended
Stock-Based Compensation Plans (Details) (USD $)	Dec. 31, 2012 item	Dec. 31, 2011	Dec. 31, 2010
Stock compensation plans
Number of stock incentive plans	3
Stock-based compensation recognized in the income statement, before taxes	$ 1,931,000	$ 1,520,000	$ 1,482,000
Capitalized equity-based compensation cost	259,000	247,000	190,000
GSWC
Stock compensation plans
Stock-based compensation recognized in the income statement, before taxes	1,667,000	1,345,000	1,139,000
Capitalized equity-based compensation cost	259,000	247,000	190,000
Nonqualified stock options \| Employees and directors
Stock compensation plans
Stock-based compensation recognized in the income statement, before taxes	150,000	302,000	579,000
Nonqualified stock options \| Employees and directors \| GSWC
Stock compensation plans
Stock-based compensation recognized in the income statement, before taxes	147,000	307,000	438,000
Restricted Stock Units \| Employees
Stock compensation plans
Stock-based compensation recognized in the income statement, before taxes	1,402,000	927,000	645,000
Restricted Stock Units \| Employees \| GSWC
Stock compensation plans
Stock-based compensation recognized in the income statement, before taxes	1,141,000	747,000	443,000
Restricted Stock Units \| Directors
Stock compensation plans
Stock-based compensation recognized in the income statement, before taxes	379,000	291,000	258,000
Restricted Stock Units \| Directors \| GSWC
Stock compensation plans
Stock-based compensation recognized in the income statement, before taxes	$ 379,000	$ 291,000	$ 258,000
2000 and 2008 Employee Plans \| Nonqualified stock options
Stock compensation plans
Expiration term	10 years
Vesting period	3 years
Percentage of rights vesting in the first two years from the date of grant	33.00%
Percentage of rights vesting in the third year from the date of grant	34.00%
2000 and 2008 Employee Plans \| Restricted Stock Units
Stock compensation plans
Vesting period	3 years
Common stock entitled to be received under each award	1
Percentage of rights vesting in the first two years from the date of grant	33.00%
Percentage of rights vesting in the third year from the date of grant	34.00%
2000 and 2008 Employee Plans \| Performance awards
Stock compensation plans
Percentage of rights vesting in the first two years from the date of grant	33.00%
Percentage of rights vesting in the third year from the date of grant	34.00%
2003 Directors Plan \| Nonqualified stock options
Stock compensation plans
Expiration term	10 years
Vesting period	3 years
2003 Directors Plan \| Restricted Stock Units
Stock compensation plans
Annual retainer multiplier used in determining awards	250.00%
Vesting rights percentage	33.30%