American States Water (AWR) 10-K 22 Feb 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Feb. 19, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	001-14431
Entity Registrant Name	American States Water Company
Entity Tax Identification Number	95-4676679
Entity Incorporation, State or Country Code	CA
Entity Address, Address Line One	630 E. Foothill Boulevard,
Entity Address, City or Town	San Dimas
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	91773-1212
City Area Code	(909)
Local Phone Number	394-3600
Title of 12(b) Security	American States Water Company Common Shares
Trading Symbol	AWR
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 2,900,179
Entity Common Stock, Shares Outstanding (in shares)		36,898,213
Documents Incorporated by Reference	Portions of the Proxy Statement of American States Water Company will be subsequently filed with the Securities and Exchange Commission as to Part III, Item Nos. 10, 11, 13 and 14 and portions of Item 12, in each case as specifically referenced herein.
Entity Central Index Key	0001056903
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
ICFR Auditor Attestation Flag	true
Subsequent Event
Entity Information [Line Items]
Entity Public Float		$ 2,876,954
GSWC
Entity Information [Line Items]
Entity File Number	001-12008
Entity Registrant Name	Golden State Water Company
Entity Tax Identification Number	95-1243678
Entity Incorporation, State or Country Code	CA
Entity Address, Address Line One	630 E. Foothill Boulevard,
Entity Address, City or Town	San Dimas
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	91773-1212
City Area Code	(909)
Local Phone Number	394-3600
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Shell Company	false
Entity Public Float			$ 0
Entity Common Stock, Shares Outstanding (in shares)		170
Entity Central Index Key	0000092116
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
GSWC | Subsequent Event
Entity Information [Line Items]
Entity Public Float		$ 0

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Regulated utility plant, at cost
Water	$ 1,784,402	$ 1,700,442
Electric	112,507	108,425
Total	1,896,909	1,808,867
Non-regulated utility property, at cost	33,315	30,554
Total utility plant, at cost	1,930,224	1,839,421
Less — accumulated depreciation	(568,326)	(543,263)
Utility plant before construction work in progress	1,361,898	1,296,158
Construction work in progress	150,145	119,547
Net utility plant	1,512,043	1,415,705
Other Property and Investments
Goodwill	1,116	1,116
Other property and investments	35,318	30,293
Total other property and investments	36,434	31,409
Current Assets
Cash and cash equivalents	36,737	1,334
Accounts receivable — customers, less allowance for doubtful accounts	29,162	20,907
Unbilled revenue — receivable (Note 2)	25,836	20,482
Receivable from U.S. government, less allowance for doubtful accounts (Note 2)	25,182	22,613
Other accounts receivable, less allowance for doubtful accounts	3,960	3,096
Income taxes receivable	103	5,685
Materials and supplies	8,619	6,429
Regulatory assets — current	13,088	20,930
Prepayments and other current assets	5,555	5,413
Contract assets (Note 2)	8,873	15,567
Total current assets	157,115	122,456
Regulatory and Other Assets
Unbilled revenue, receivable from U.S government	9,945	8,621
Receivable from U.S. government (Note 2)	49,488	42,206
Contract assets (Note 2)	1,384	64
Operating lease right-of-use assets	11,146	13,168
Regulatory Assets, Noncurrent	3,451	0
Other	10,597	7,702
Total other assets	86,011	71,761
Total Assets	1,791,603	1,641,331
Capitalization
Common shareholders' equity	641,673	601,530
Long-term debt	440,348	280,996
Total capitalization	1,082,021	882,526
Current Liabilities
Notes payable to banks	0	5,000
Long-term debt -current	358	344
Accounts payable	63,788	55,616
Income taxes payable	6,783	95
Accrued other taxes	11,902	11,110
Accrued employee expenses	15,122	14,255
Accrued interest	4,832	3,050
Unrealized loss on purchased power contracts	1,537	3,171
Contract liabilities (Note 2)	1,800	11,167
Operating lease liabilities	2,013	1,849
Other	10,437	10,341
Total current liabilities	118,572	115,998
Other Credits
Notes payable to banks	134,200	200,000
Advances for Construction	63,374	63,989
Contributions in aid of construction — net	140,332	134,706
Deferred income taxes	131,172	125,304
Regulatory liabilities	0	23,380
Unamortized investment tax credits	1,224	1,295
Accrued pension and other post-retirement benefits	95,639	68,469
Operating lease liabilities	9,636	11,739
Other	15,433	13,925
Total other credits	591,010	642,807
Commitments and Contingencies
Liabilities and Equity, Total	1,791,603	1,641,331
GSWC
Regulated utility plant, at cost
Water	1,784,402	1,700,442
Electric	0	108,425
Total utility plant, at cost	1,784,402	1,808,867
Less — accumulated depreciation	(502,283)	(531,801)
Utility plant before construction work in progress	1,282,119	1,277,066
Construction work in progress	118,370	117,676
Net utility plant	1,400,489	1,394,742
Other Property and Investments
Other property and investments	33,240	28,212
Total other property and investments	33,240	28,212
Current Assets
Cash and cash equivalents	35,578	401
Accounts receivable — customers, less allowance for doubtful accounts	26,920	20,907
Unbilled revenue — receivable (Note 2)	19,330	18,636
Other accounts receivable, less allowance for doubtful accounts	3,255	1,857
Intercompany receivable	1,107	0
Income taxes receivable	0	7,727
Materials and supplies	3,659	4,920
Regulatory assets — current	11,325	20,930
Prepayments and other current assets	4,114	4,497
Total current assets	105,288	79,875
Regulatory and Other Assets
Operating lease right-of-use assets	11,103	12,745
Regulatory Assets, Noncurrent	1,048	0
Other	9,614	6,880
Total other assets	21,765	19,625
Total Assets	1,560,782	1,522,454
Capitalization
Common shareholders' equity	583,298	551,188
Long-term debt	440,348	280,996
Total capitalization	1,023,646	832,184
Current Liabilities
Long-term debt -current	358	344
Intercompany payable to Parent	0	158,845
Accounts payable	45,613	45,756
Income taxes payable	4,612	0
Accrued other taxes	10,382	10,640
Accrued employee expenses	12,351	12,386
Accrued interest	4,545	2,736
Unrealized loss on purchased power contracts	0	3,171
Operating lease liabilities	1,956	1,612
Other	9,403	9,745
Total current liabilities	89,220	245,235
Other Credits
Advances for Construction	63,354	63,989
Contributions in aid of construction — net	138,691	134,706
Deferred income taxes	124,581	127,806
Regulatory liabilities	0	23,380
Unamortized investment tax credits	1,224	1,295
Accrued pension and other post-retirement benefits	95,570	68,469
Operating lease liabilities	9,636	11,588
Other	14,860	13,802
Total other credits	447,916	445,035
Liabilities and Equity, Total	$ 1,560,782	$ 1,522,454

CONSOLIDATED STATEMENTS OF CAPI

CONSOLIDATED STATEMENTS OF CAPITALIZATION - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Common Stock, Par or Stated Value Per Share	$ 0	$ 0
Common stock, shares outstanding	36,889,103	36,846,614
Common stock, shares authorized	60,000,000	60,000,000
Common Shareholders' Equity:
Common shares, no par value	$ 256,666	$ 255,566
Reinvested earnings in the business	385,007	345,964
Common shareholders' equity	641,673	601,530
Long-Term Debt
Debt and Lease Obligation	444,271	284,699
Less: Current maturities	(358)	(344)
Debt Issuance Costs, Net	(3,565)	(3,359)
Long-Term Debt	440,348	280,996
Total Capitalization	$ 1,082,021	$ 882,526
GSWC
Common Stock, Par or Stated Value Per Share	$ 0	$ 0
Common stock, shares outstanding	170	165
Common stock, shares authorized	1,000	1,000
Common Shareholders' Equity:
Common shares, no par value	$ 354,906	$ 293,754
Reinvested earnings in the business	228,392	257,434
Common shareholders' equity	583,298	551,188
Long-Term Debt
Debt and Lease Obligation	444,271	284,699
Less: Current maturities	(358)	(344)
Debt Issuance Costs, Net	(3,565)	(3,359)
Long-Term Debt	440,348	280,996
Total Capitalization	1,023,646	832,184
6.81% notes due 2028
Long-Term Debt
Debt and Lease Obligation	$ 15,000	$ 15,000
Interest rate per annum (as a percent)	6.81%	6.81%
6.81% notes due 2028 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 15,000	$ 15,000
Interest rate per annum (as a percent)	6.81%	6.81%
6.59% notes due 2029
Long-Term Debt
Debt and Lease Obligation	$ 40,000	$ 40,000
Interest rate per annum (as a percent)	6.59%	6.59%
6.59% notes due 2029 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 40,000	$ 40,000
Interest rate per annum (as a percent)	6.59%	6.59%
7.875% notes due 2030
Long-Term Debt
Debt and Lease Obligation	$ 20,000	$ 20,000
Interest rate per annum (as a percent)	7.875%	7.875%
7.875% notes due 2030 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 20,000	$ 20,000
Interest rate per annum (as a percent)	7.875%	7.875%
7.23% notes due 2031
Long-Term Debt
Debt and Lease Obligation	$ 50,000	$ 50,000
Interest rate per annum (as a percent)	7.23%	7.23%
7.23% notes due 2031 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 50,000	$ 50,000
Interest rate per annum (as a percent)	7.23%	7.23%
6.00% notes due 2041
Long-Term Debt
Debt and Lease Obligation	$ 62,000	$ 62,000
Interest rate per annum (as a percent)	6.00%	6.00%
6.00% notes due 2041 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 62,000	$ 62,000
Interest rate per annum (as a percent)	6.00%	6.00%
3.45% notes due 2029
Long-Term Debt
Debt and Lease Obligation	$ 15,000	$ 15,000
Interest rate per annum (as a percent)	3.45%	3.45%
3.45% notes due 2029 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 15,000	$ 15,000
Interest rate per annum (as a percent)	3.45%	3.45%
9.56% notes due 2031
Long-Term Debt
Debt and Lease Obligation	$ 28,000	$ 28,000
Interest rate per annum (as a percent)	9.56%	9.56%
9.56% notes due 2031 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 28,000	$ 28,000
Interest rate per annum (as a percent)	9.56%	9.56%
5.87% notes due 2028
Long-Term Debt
Debt and Lease Obligation	$ 40,000	$ 40,000
Interest rate per annum (as a percent)	5.87%	5.87%
5.87% notes due 2028 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 40,000	$ 40,000
Interest rate per annum (as a percent)	5.87%	5.87%
2.17% notes due 2030
Long-Term Debt
Debt and Lease Obligation	$ 85,000	$ 0
Interest rate per annum (as a percent)	2.17%
2.17% notes due 2030 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 85,000	0
Interest rate per annum (as a percent)	2.17%
2.90% notes due 2040
Long-Term Debt
Debt and Lease Obligation	$ 75,000	0
Interest rate per annum (as a percent)	2.90%
2.90% notes due 2040 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 75,000	0
Interest rate per annum (as a percent)	2.90%
5.50% notes due 2026
Long-Term Debt
Debt and Lease Obligation	$ 7,730	$ 7,730
Interest rate per annum (as a percent)	5.50%	5.50%
5.50% notes due 2026 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 7,730	$ 7,730
Interest rate per annum (as a percent)	5.50%	5.50%
State Water Project due 2035
Long-Term Debt
Debt and Lease Obligation	$ 3,322	$ 3,563
State Water Project due 2035 | GSWC
Long-Term Debt
Debt and Lease Obligation	3,322	3,563
American Recovery and Reinvestment Act Obligation due 2033
Long-Term Debt
Debt and Lease Obligation	3,219	3,406
American Recovery and Reinvestment Act Obligation due 2033 | GSWC
Long-Term Debt
Debt and Lease Obligation	$ 3,219	$ 3,406

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Revenues
Water	$ 330,637	$ 319,830	$ 295,258
Electric	37,024	39,548	34,350
Contracted services	120,582	114,491	107,208
Total operating revenues	488,243	473,869	436,816
Operating Expenses
Water purchased	74,554	72,289	68,904
Power purchased for pumping	10,134	8,660	8,971
Groundwater production assessment	20,392	18,962	19,440
Power purchased for resale	10,423	11,796	11,590
Supply cost balancing accounts	(11,803)	(7,026)	(15,649)
Other operation	33,236	32,756	31,650
Administrative and general	83,615	83,034	82,595
Depreciation and amortization	36,850	35,397	40,425
Maintenance	15,702	15,466	15,682
Property and other taxes	22,199	20,042	18,404
ASUS construction	62,411	55,673	53,906
(Gain) loss on sale of assets	31	(253)	(85)
Total operating expenses	357,744	346,796	335,833
Operating Income	130,499	127,073	100,983
Other Income and Expenses
Interest expense	(22,531)	(24,586)	(23,433)
Interest income	1,801	3,249	3,578
Other, net	4,853	3,276	760
Total other income and expenses	(15,877)	(18,061)	(19,095)
Income before income tax expense	114,622	109,012	81,888
Income tax expense	28,197	24,670	18,017
Net Income	$ 86,425	$ 84,342	$ 63,871
Basic Earnings Per Common Share
Weighted Average Number of Shares Outstanding (in shares)	36,880	36,814	36,733
Earnings Per Share, Basic	$ 2.34	$ 2.28	$ 1.73
Fully Diluted Earnings Per Share
Weighted Average Number of Diluted Shares (in shares)	36,995	36,964	36,936
Earnings Per Share, Diluted	$ 2.33	$ 2.28	$ 1.72
Dividends Paid Per Common Share	$ 1.28	$ 1.16	$ 1.06
GSWC
Operating Revenues
Water	$ 330,637	$ 319,830	$ 295,258
Electric	18,647	39,548	34,350
Total operating revenues	349,284	359,378	329,608
Operating Expenses
Water purchased	74,554	72,289	68,904
Power purchased for pumping	10,134	8,660	8,971
Groundwater production assessment	20,392	18,962	19,440
Power purchased for resale	5,010	11,796	11,590
Supply cost balancing accounts	(11,749)	(7,026)	(15,649)
Other operation	25,194	26,336	25,334
Administrative and general	59,385	59,905	62,156
Depreciation and amortization	32,184	32,441	38,395
Maintenance	12,424	12,843	13,104
Property and other taxes	18,860	18,168	16,809
(Gain) loss on sale of assets	0	(88)	(8)
Total operating expenses	246,388	254,286	249,046
Operating Income	102,896	105,092	80,562
Other Income and Expenses
Interest expense	(21,495)	(23,399)	(22,621)
Interest income	718	1,867	2,890
Other, net	4,556	3,280	784
Total other income and expenses	(16,221)	(18,252)	(18,947)
Income before income tax expense	86,675	86,840	61,615
Income tax expense	21,704	20,177	13,603
Net Income	$ 64,971	$ 66,663	$ 48,012

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN COMMON SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	GSWC	Common Stock [Member]	Common Stock [Member]GSWC	Earnings Reinvested in the Business	Earnings Reinvested in the BusinessGSWC
Common stock, shares outstanding			36,681,000	146
Balances at Dec. 31, 2017	$ 529,945	$ 474,374	$ 250,124	$ 242,181	$ 279,821	$ 232,193
Add:
Net Income	63,871	48,012			63,871	48,012
Exercise of stock options and other issuance of Common Shares			77,000	19
Exercise of stock options and other issuance of Common Shares	546	47,500	$ 546	$ 47,500
Stock-based compensation, net of taxes paid from shares withheld from employees related to net share settlements	2,798	2,539	2,798	2,539
Dividend equivalent rights on stock-based awards not paid in cash	221	192	221	192
Deduct:
Dividends on Common Shares	38,937	68,850			38,937	68,850
Dividend equivalent rights on stock-based awards	221	192			221	192
Balances at Dec. 31, 2018	558,223	503,575	$ 253,689	$ 292,412	304,534	211,163
Common stock, shares outstanding			36,758,000	165
Add:
Net Income	84,342	66,663			84,342	66,663
Exercise of stock options and other issuance of Common Shares			89,000	0
Exercise of stock options and other issuance of Common Shares	519		$ 519
Stock-based compensation, net of taxes paid from shares withheld from employees related to net share settlements	1,148	1,150	1,148	$ 1,150
Dividend equivalent rights on stock-based awards not paid in cash	210	192	210	192
Deduct:
Dividends on Common Shares	42,702	20,200			42,702	20,200
Dividend equivalent rights on stock-based awards	210	192			210	192
Balances at Dec. 31, 2019	$ 601,530	$ 551,188	$ 255,566	$ 293,754	345,964	257,434
Common stock, shares outstanding	36,846,614	165	36,847,000	165
Add:
Net Income	$ 86,425	$ 64,971			86,425	64,971
Exercise of stock options and other issuance of Common Shares			42,000	5
Exercise of stock options and other issuance of Common Shares	30	60,000	$ 30	$ 60,000
Stock-based compensation, net of taxes paid from shares withheld from employees related to net share settlements	894	983	894	983
Dividend equivalent rights on stock-based awards not paid in cash	176	169	176	169
Deduct:
Dividends on Common Shares	47,206	22,500			47,206	22,500
Dividends		71,344				71,344
Dividend equivalent rights on stock-based awards	176	169			176	169
Balances at Dec. 31, 2020	$ 641,673	$ 583,298	$ 256,666	$ 354,906	$ 385,007	$ 228,392
Common stock, shares outstanding	36,889,103	170	36,889,000	170

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows From Operating Activities:
Net Income	$ 86,425	$ 84,342	$ 63,871
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	37,204	35,713	40,663
Provision for doubtful accounts	1,433	608	841
Deferred income taxes and investment tax credits	2,243	6,623	(5,773)
Stock-based compensation expense	2,463	2,517	3,851
(Gain) loss on sale of assets	31	(253)	(85)
(Gain) loss on investments held in a trust	(3,024)	(3,580)	558
Other - net	(908)	526	97
Changes in assets and liabilities:
Accounts receivable - customers	(13,272)	1,882	1,882
Unbilled revenue- receivable	6,678	5,515	(2,823)
Other accounts receivable	(1,204)	214	5,151
Receivable from the U.S. government	3,889	(1,144)	20,976
Materials and supplies	(2,190)	(654)	(980)
Prepayments and other assets	1,686	3,978	(519)
Contract Assets	(588)	3,979	5,941
Regulatory Assets / Liabilities	10,150	(11,597)	33,834
Accounts payable	5,348	(249)	1,282
Income taxes receivable / payable	12,270	(3,786)	2,708
Contract liabilities	(9,367)	3,637	3,619
Accrued pension and other post-retirement benefits	1,444	1,994	(1,086)
Other liabilities	2,593	(4,659)	(928)
Cash Flows From Operating Activities	122,170	116,864	136,774
Cash Flows From Investing Activities:
Capital expenditures	(130,423)	(151,940)	(126,561)
Proceeds from sale of assets	88	169	72
Other investments	1,275	1,424	1,553
Net Cash Provided by (Used in) Investing Activities	(131,610)	(153,195)	(128,042)
Cash Flows From Financing Activities:
Proceeds from stock option exercises	30	519	546
Proceeds from Advances for Construction	9,338	10,171	5,551
Refunds on advances for construction	3,729	5,005	3,886
Retirement or repayments of long-term debt	(336)	(40,325)	(326)
Increase (Decrease) in Notes Payable, Current	(70,800)	109,500	36,500
Proceeds from issuance of long-term debt, net of issuance costs	159,413	0	0
Dividends paid	(47,206)	(42,702)	(38,937)
Other	(1,867)	(1,634)	(1,253)
Net Cash Provided by (Used in) Financing Activities	44,843	30,524	(1,805)
Net change in cash and cash equivalents	35,403	(5,807)	6,927
Cash and cash equivalents, beginning of period	1,334	7,141	214
Cash and cash equivalents, end of year	36,737	1,334	7,141
GSWC
Cash Flows From Operating Activities:
Net Income	64,971	66,663	48,012
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	32,477	32,757	38,633
Provision for doubtful accounts	1,018	606	850
Deferred income taxes and investment tax credits	1,181	5,081	(6,817)
Stock-based compensation expense	2,349	2,253	3,397
(Gain) loss on sale of assets	0	(88)	(8)
(Gain) loss on investments held in a trust	(3,024)	(3,580)	558
Other - net	(576)	58	27
Changes in assets and liabilities:
Accounts receivable - customers	(12,126)	1,882	1,882
Unbilled revenue- receivable	1,693	744	(960)
Other accounts receivable	(1,364)	311	4,140
Materials and supplies	(2,166)	(123)	(751)
Prepayments and other assets	1,124	4,230	(154)
Regulatory Assets / Liabilities	13,278	(11,597)	33,834
Accounts payable	1,810	1,558	(1,907)
Inter-company receivable / payable	(1,911)	1,056	(47)
Income taxes receivable / payable	12,339	(2,110)	973
Accrued pension and other post-retirement benefits	1,390	1,994	(1,086)
Other liabilities	1,260	(3,579)	(2,057)
Cash Flows From Operating Activities	110,337	96,628	120,439
Cash Flows From Investing Activities:
Capital expenditures	(116,409)	(142,852)	(116,354)
Note receivable from AWR parent	(6,000)	0	0
Receipt of payment of note receivable from AWR parent	6,000	0	0
Proceeds from sale of assets	0	88	9
Other investments	1,275	1,424	1,553
Net Cash Provided by (Used in) Investing Activities	(117,684)	(144,188)	(117,898)
Cash Flows From Financing Activities:
Proceeds from issuance of Common Shares to Parent	60,000	0	47,500
Proceeds from Advances for Construction	9,338	10,171	5,551
Refunds on advances for construction	3,729	5,005	3,886
Retirement or repayments of long-term debt	(336)	(40,325)	(326)
Proceeds from issuance of long-term debt, net of issuance costs	159,413	0	0
Net change in inter-company borrowings	158,000	(100,500)	(22,500)
Dividends paid	(22,500)	(20,200)	(68,850)
Other	(1,662)	(1,367)	(1,057)
Net Cash Provided by (Used in) Financing Activities	42,524	43,774	1,432
Net change in cash and cash equivalents	35,177	(3,786)	3,973
Cash and cash equivalents, beginning of period	401	4,187	214
Cash and cash equivalents, end of year	$ 35,578	$ 401	$ 4,187

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations : American States Water Company (“AWR”) is the parent company of Golden State Water Company (“GSWC”), Bear Valley Electric Service Inc. ("BVESI"), and American States Utility Services, Inc. (“ASUS”) (and its wholly owned subsidiaries, Fort Bliss Water Services Company (“FBWS”), Terrapin Utility Services, Inc. (“TUS”), Old Dominion Utility Services, Inc. (“ODUS”), Palmetto State Utility Services, Inc. (“PSUS”), Old North Utility Services, Inc. (“ONUS”), Emerald Coast Utility Services, Inc. (“ECUS”), and Fort Riley Utility Services, Inc. ("FRUS")). AWR and its subsidiaries may be collectively referred to as “Registrant” or “the Company.” The subsidiaries of ASUS are collectively referred to as the “Military Utility Privatization Subsidiaries.” On July 1, 2020, GSWC completed the transfer of the electric utility assets and liabilities from its electric division to BVESI, a separate legal entity and wholly owned subsidiary of AWR (Note 20). This reorganization did not result in any substantive changes to AWR's operations and business segments. AWR, through its wholly owned subsidiaries, serves over one million people in nine states. GSWC and BVESI are both California public utilities, with GSWC engaged in the purchase, production, distribution and sale of water throughout California serving approximately 261,800 customers, while BVESI distributes electricity in several San Bernardino County mountain communities in California serving approximately 24,500 customers. The California Public Utilities Commission (“CPUC”) regulates GSWC’s and BVESI's businesses in matters including properties, rates, services, facilities, and transactions between GSWC, BVESI, and their affiliates. ASUS, through its Military Utility Privatization Subsidiaries, operates, maintains and performs construction activities (including renewal and replacement capital work) on water and/or wastewater systems at various U.S. military bases pursuant to 50-year firm fixed-price contracts. These contracts are subject to annual economic price adjustments and modifications for changes in circumstances, changes in laws and regulations and additions to the contract value for new construction of facilities at the military bases. There is no direct regulatory oversight by the CPUC over AWR or the operations, rates or services provided by ASUS or the Military Utility Privatization Subsidiaries. Basis of Presentation : The consolidated financial statements and notes thereto are presented in a combined report filed by two separate Registrants: AWR and GSWC. References in this report to “Registrant” are to AWR and GSWC, collectively, unless otherwise specified. AWR owns all of the outstanding Common Shares of GSWC, BVESI and ASUS. ASUS owns all of the outstanding common shares of the Military Utility Privatization Subsidiaries. The consolidated financial statements of AWR include the accounts of AWR and its subsidiaries. These financial statements are prepared in conformity with accounting principles generally accepted in the United States of America. Intercompany transactions and balances have been eliminated in the AWR consolidated financial statements. Related-Party Transactions : GSWC, BVESI and ASUS provide and/or receive various support services to and from their parent, AWR, and among themselves. GSWC also allocates certain corporate office administrative and general costs to its affiliates using allocation factors approved by the CPUC. During the years ended December 31, 2020, 2019 and 2018, GSWC allocated to ASUS approximately $4.9 million, $4.7 million and $4.2 million, respectively, of corporate office administrative and general costs. During the year ended December 31, 2020, GSWC allocated corporate office administrative and general costs to BVESI of approximately $1.3 million. Furthermore, AWR borrows under a credit facility, which expires in May 2023, and provides funds to GSWC and ASUS in support of their operations. The interest rate charged to GSWC and ASUS is sufficient to cover AWR’s interest expense under the credit facility. The CPUC requires GSWC to pay down all intercompany borrowings from AWR within a 24-month period, which was required by November 2020. In October 2020, the Board of Directors authorized AWR to invest equity in GSWC to enable the subsidiary to pay down all its intercompany borrowings. During the fourth quarter of 2020, AWR invested $60 million of equity in GSWC and received five shares of GSWC common stock. The majority of the proceeds from this stock issuance were used by GSWC to pay down its intercompany borrowings from AWR, satisfying the CPUC’s requirement. As a result, GSWC had no intercompany borrowings from AWR as of December 31, 2020. In October 2020, AWR issued an interest bearing promissory note to GSWC, which expires in May 2023. Under the terms of the note, AWR may borrow from GSWC amounts up to $30 million for working capital purposes. AWR agrees to pay any unpaid principal amounts outstanding under this note, plus accrued interest. In November 2020, AWR borrowed $6 million from GSWC under the terms of the note, which was subsequently repaid in December. As of December 31, 2020, there were no amounts outstanding under this note. COVID-19 Impact : GSWC, BVESI, and ASUS have continued their operations given that their water, wastewater, and electric utility services are deemed essential. AWR's responses take into account orders issued by the CPUC, and the guidance provided by federal, state, and local health authorities and other government officials to the COVID-19 pandemic. Some of the actions taken by GSWC and BVESI include: (i) suspending service disconnections for nonpayment pursuant to CPUC orders; (ii) increasing the number of employees telecommuting; and (iii) delaying some capital improvement projects at GSWC. In February 2021, the CPUC adopted a resolution that extended the existing emergency customer protections previously established by the CPUC through June 30, 2021, including the suspension of service disconnections for non-payment, in response to the on-going COVID-19 pandemic. Among other things, the resolution also extends the COVID-19-related memorandum accounts established to track incremental costs associated with complying with the resolution, and requires utilities in California to file transition plans to address the eventual discontinuance of the emergency customer protections. The goal of the transition plan is to effectively ease customers through a transition off the emergency customer protections by proactively communicating with customers to enroll them in programs to manage their utility bills and informing them of the changes to programs in which they are already enrolled. GSWC and BVESI are in the process of developing their transition plans, which are required to be finalized and filed with the CPUC by April 1, 2021. The pandemic has caused significant volatility on financial markets, resulting in significant fluctuations in the fair value of plan assets in GSWC's pension and other retirement plans, which could continue. In addition, due to expected future credit losses on utility customer bills, GSWC and BVESI have increased their allowance for doubtful accounts as of December 31, 2020. However, the CPUC has authorized GSWC and BVESI to track incremental costs, including bad debt expense in excess of what is included in their respective revenue requirements, incurred as a result of the pandemic in COVID-19-related memorandum accounts, such as a Catastrophic Event Memorandum Account ("CEMA"), to be filed with the CPUC for future recovery. GSWC and BVESI have recorded approximately $4.4 million in these accounts as regulatory assets, as it is believed such amounts are probable of recovery. CEMA and other emergency-type memorandum accounts are established as a result of a state/federal declared emergency, and are therefore recognized as regulatory assets for future recovery. As a result, the amounts recorded in the COVID-19-related memorandum accounts have not impacted GSWC's and BVESI's earnings in 2020. Thus far, the COVID-19 pandemic has not had a material impact on ASUS's operations. Utility Accounting : Registrant’s accounting policies conform to accounting principles generally accepted in the United States of America ("GAAP"), including the accounting principles for rate-regulated enterprises, which reflect the ratemaking policies of the CPUC and, to the extent applicable, the Federal Energy Regulatory Commission. GSWC and BVESI have incurred various costs and received various credits reflected as regulatory assets and liabilities. Accounting for such costs and credits as regulatory assets and liabilities is in accordance with the guidance for accounting for the effects of certain types of regulation. This guidance sets forth the application of GAAP for those companies whose rates are established by or are subject to approval by an independent third-party regulator. Under such accounting guidance, rate-regulated entities defer costs and credits on the balance sheet as regulatory assets and liabilities when it is probable that those costs and credits will be recognized in the ratemaking process in a period different from the period in which they would have been reflected in income by an unregulated company. These regulatory assets and liabilities are then recognized in the income statement in the period in which the same amounts are reflected in the rates charged for service. The amounts included as regulatory assets and liabilities that will be collected or refunded over a period exceeding one year are classified as long-term assets and liabilities as of December 31, 2020 and 2019. Property and Depreciation : Registrant's property consists primarily of regulated utility plant at GSWC and BVESI. GSWC and BVESI capitalize, as utility plant, the cost of construction and the cost of additions, betterments and replacements of retired units of property. Such cost includes labor, material and certain indirect charges. Water systems acquired are recorded at estimated original cost of utility plant when first devoted to utility service and the applicable depreciation is recorded to accumulated depreciation. The difference between the estimated original cost, less accumulated depreciation, and the purchase price, if recognized by the CPUC, is recorded as an acquisition adjustment within utility plant. Depreciation is computed on the straight-line, remaining-life basis, group method, in accordance with the applicable ratemaking process. The provision for depreciation expressed as a percentage of the aggregate depreciable asset balances for regulated utilities was 2.2% for 2020, 2.2% for 2019, and 2.7% for 2018. Depreciation expense for regulated utilities, excluding amortization expense and depreciation on transportation equipment, totaled $32.9 million, $31.7 million and $37.3 million for the years ended December 31, 2020, 2019 and 2018, respectively. Depreciation computed on regulated utilities’ transportation equipment is recorded in other operating expenses and totaled $353,000, $316,000 and $238,000 for the years ended December 31, 2020, 2019 and 2018, respectively. Expenditures for maintenance and repairs are expensed as incurred. Retired property costs, including costs of removal, are charged to the accumulated provision for depreciation. Estimated useful lives of regulated utilities’ utility plant, as authorized by the CPUC, are as follows: Source of water supply 30 years to 50 years Pumping 25 years to 40 years Water treatment 20 years to 35 years Transmission and distribution 25 years to 55 years Generation 40 years Other plant 7 years to 40 years Non-regulated property consists primarily of equipment utilized by ASUS and its subsidiaries for its operations. This property is stated at cost, net of accumulated depreciation, which is calculated using the straight-line method over the useful lives of the assets. Asset Retirement Obligations : GSWC has a legal obligation for the retirement of its wells, which by law need to be properly capped at the time of removal. As such, GSWC incurs asset retirement obligations. GSWC records the fair value of a liability for these asset retirement obligations in the period in which they are incurred. When the liability is initially recorded, GSWC capitalizes the cost by increasing the carrying amount of the related long-lived asset. Over time, the liability is accreted to its present value each period, and the capitalized cost is depreciated over the useful life of the related asset. Upon settlement of the liability, GSWC either settles the obligation for its recorded amount or incurs a gain or loss upon settlement. Retirement costs have historically been recovered through rates subsequent to the retirement costs being incurred. Accordingly, recoverability of GSWC’s asset retirement obligations are reflected as a regulatory asset. GSWC also reflects the loss or gain at settlement as a regulatory asset or liability on the balance sheet. With regards to removal costs associated with certain other long-lived assets, such as water mains, distribution and transmission assets, asset retirement obligations have not been recognized as GSWC believes there is no legal obligation to do so. There are no CPUC rules or regulations that require GSWC to remove any of its other long-lived assets. In addition, GSWC’s water pipelines are not subject to regulation by any federal regulatory agency. GSWC has franchise agreements with various municipalities in order to use the public right of way for utility purposes (i.e., operate water distribution and transmission assets), and if certain events occur in the future, GSWC could be required to remove or relocate certain of its pipelines. However, it is not possible to estimate an asset retirement amount since the timing and the amount of assets that may be required to be removed, if any, is not known. Amounts recorded for asset retirement obligations are subject to various assumptions and determinations, such as determining whether a legal obligation exists to remove assets, estimating the fair value of the costs of removal, when final removal will occur and the credit-adjusted risk-free interest rates to be utilized on discounting future liabilities. Changes that may arise over time with regard to these assumptions will change amounts recorded in the future. Revisions in estimates for timing or estimated cash flows are recognized as changes in the carrying amount of the liability and the related capitalized asset. The estimated fair value of the costs of removal was based on third-party costs. Impairment of Long-Lived Assets : Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be fully recoverable in accordance with accounting guidance for impairment or disposal of long-lived assets. Registrant would recognize an impairment loss on its regulated assets only if the carrying value amount of a long-lived asset is not recoverable from customer rates authorized by the CPUC. Impairment loss is measured as the excess of the carrying value over the amounts recovered in customer rates. For the years ended December 31, 2020, 2019 and 2018, no impairment loss was incurred. Goodwill : At December 31, 2020 and 2019, AWR had approximately $1.1 million of goodwill. The $1.1 million goodwill arose from ASUS’s acquisition of a subcontractor’s business at some of the Military Utility Privatization Subsidiaries. In accordance with the accounting guidance for testing goodwill, AWR annually assesses qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. For 2020, AWR’s assessment of qualitative factors did not indicate that an impairment had occurred for goodwill at ASUS. Cash and Cash Equivalents : Cash and cash equivalents include short-term cash investments with an original maturity of three months or less. At times, cash and cash equivalent balances may be in excess of federally insured limits. Cash and cash equivalents are held with financial institutions with high credit standings. Accounts Receivable : Accounts receivable is reported on the balance sheet net of any allowance for doubtful accounts. The allowance for doubtful accounts is Registrant’s best estimate of the amount of probable credit losses in Registrant’s existing accounts receivable from its water and electric customers, and is determined based on expected losses rather than incurred losses. Registrant reviews the allowance for doubtful accounts quarterly. Account balances are written off against the allowance when it is probable the receivable will not be recovered. When utility customers request extended payment terms, credit is extended based on regulatory guidelines, and collateral is not required. Receivables from the U.S. government include amounts due under contracts with the U.S. government to operate and maintain, and/or provide construction services for the water and/or wastewater systems at military bases. Other accounts receivable consist primarily of amounts due from third parties (non-utility customers) for various reasons, including amounts due from contractors, amounts due under settlement agreements and amounts due from other third-party prime government contractors pursuant to agreements for construction of water and/or wastewater facilities for such third-party prime contractors. The allowance for these other accounts receivable is based on Registrant’s evaluation of the receivable portfolio under current conditions and a review of specific problems and such other factors that, in Registrant’s judgment, should be considered in estimating losses. Allowances for doubtful accounts are disclosed in Note 18. Registrant adopted Accounting Standards Update 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments effective January 1, 2020. Materials and Supplies : Materials and supplies are stated at the lower of cost or net realizable value. Cost is computed using weighted average cost. Major classes of materials include pipe, hydrants and valves. Interest : Interest incurred during the construction of capital assets has generally not been capitalized for financial reporting purposes as such policy is not followed in the ratemaking process. Interest expense is generally recovered through the regulatory process. However, the CPUC has authorized certain capital projects to be filed for revenue recovery with advice letters when those projects are completed. During the time that such projects are under development and construction, GSWC and BVESI may accrue an allowance for funds used during construction (“AFUDC”) on the incurred expenditures to offset the cost of financing project construction. For the year ended December 31, 2020, BVESI recorded $200,000 in AFUDC. For the years ended December 31, 2019 and 2018, the amount of AFUDC recorded was immaterial. Debt Issuance Costs and Redemption Premiums : Original debt issuance costs are deducted from the carrying value of the associated debt liability and amortized over the lives of the respective issues. Premiums paid on the early redemption of debt, which is reacquired through refunding, are deferred and amortized over the life of the debt issued to finance the refunding as GSWC normally receives recovery of these costs in rates. Advances for Construction and Contributions in Aid of Construction : Advances for construction represent amounts advanced by developers for the cost to construct water system facilities in order to extend water service to their properties. Advances are refundable in equal annual installments, generally over 40 years. In certain instances, GSWC makes refunds on these advances over a specific period of time based on operating revenues related to the main or as new customers are connected to receive service from the main. Contributions in aid of construction are similar to advances but require no refunding. Generally, GSWC and BVESI depreciate contributed property and amortizes contributions in aid of construction at the composite rate of the related property. Utility plant funded by advances and contributions is excluded from rate base. Fair Value of Financial Instruments : For cash and cash equivalents, accounts receivable, accounts payable and short-term debt, the carrying amount is assumed to approximate fair value due to the short-term nature of the amounts. The table below estimates the fair value of long-term debt issued by GSWC. Rates available to GSWC at December 31, 2020 and 2019 for debt with similar terms and remaining maturities were used to estimate fair value for long-term debt. Changes in the assumptions will produce differing results. 2020 2019 (dollars in thousands) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt—GSWC (1) $ 444,271 $ 559,752 $ 284,699 $ 376,467 (1) Excludes debt issuance costs and redemption premiums. The accounting guidance for fair value measurements applies to all financial assets and financial liabilities that are being measured and reported on a fair value basis. Under the accounting guidance, GSWC makes fair value measurements on its publicly issued notes, private placement notes and other long-term debt using current U.S. corporate bond yields for similar debt instruments. Under the fair value guidance, these are classified as Level 2, which consists of quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. The following table sets forth by level, within the fair value hierarchy, GSWC’s long-term debt measured at fair value as of December 31, 2020: (dollars in thousands) Level 1 Level 2 Level 3 Total Long-term debt—GSWC — $ 559,752 — $ 559,752 Stock-Based Awards : AWR has issued stock-based awards to its employees under stock incentive plans. AWR has also issued stock-based awards to its Board of Directors under non-employee directors stock plans. Registrant applies the provisions in the accounting guidance for share-based payments in accounting for all of its stock-based awards. See Note 13 for further discussion. Recently Issued Accounting Pronouncements : Accounting Pronouncements Adopted in 2020 In June 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, and issued further guidance in November 2018 and May 2019 related to the impairment of financial instruments, effective January 1, 2020. The new guidance provides an impairment model, known as the current expected credit loss model, which is based on expected credit losses rather than incurred losses over the remaining life of most financial assets measured at amortized cost, including trade and other receivables. For 2020, Registrant has increased its allowance for doubtful accounts for utility customer accounts receivable, largely due to Registrant's current estimate of the expected associated economic impact of the COVID-19 pandemic (see Note 18). In August 2018, the FASB issued ASU 2018-14, Compensation-Retirement Benefits—Defined Benefit Plans-General (Subtopic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans . This ASU removes disclosures to pension plans and other retirement plans that no longer are considered cost beneficial, clarifies the specific disclosure requirements and adds disclosure requirements deemed relevant. This ASU was adopted by Registrant effective December 31, 2020 and applied on a retrospective basis to all periods presented. The adoption of this guidance did not have a material impact on the Registrant's financial statements and disclosures. Accounting Pronouncements to be Adopted in Future Periods In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes . The amendments in this update simplify the accounting for income taxes by removing certain exceptions and clarifying certain requirements regarding franchise taxes, goodwill, consolidated tax expenses, and annual effective tax rate calculations. The ASU is effective for fiscal years beginning after December 15, 2020. Registrant will adopt this guidance effective January 1, 2021, which is not expected to have a material impact on its financial statements.

Revenues

Revenues	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenues	Revenues Most of Registrant's revenues are accounted for under the revenue recognition accounting standard, "Revenue from Contracts with Customers - (Topic 606)." GSWC and BVESI provide utility services to customers as specified by the CPUC. The transaction prices for water and electric revenues are based on tariff rates authorized by the CPUC, which include both quantity-based and flat-rate charges. Tariff revenues represent the adopted revenue requirement authorized by the CPUC intended to provide GSWC and BVESI with an opportunity to recover its costs and earn a reasonable return on its net capital investment. The annual revenue requirements are comprised of operation and maintenance costs, administrative and general costs, depreciation and taxes in amounts authorized by the CPUC and a return on rate base consistent with the capital structure authorized by the CPUC. Water and electric revenues are recognized over time as customers simultaneously receive and use the utility services provided. Water and electric revenues include amounts billed to customers on a cyclical basis, nearly all of which are based on meter readings for services provided. Customer bills also include surcharges for cost-recovery activities, which represent CPUC-authorized balancing and memorandum accounts that allow for the recovery of previously incurred operating costs. Revenues from these surcharges do not impact earnings as they are offset by corresponding increases in operating expenses to reflect the recovery of the associated costs. Customer payment terms are approximately 20 business days from the billing date. Unbilled revenues are amounts estimated to be billed for usage since the last meter-reading date to the end of the accounting period. The most recent customer billed usage forms the basis for estimating unbilled revenue. GSWC and BVESI bill certain sales and use taxes levied by state or local governments to its customers. Included in these sales and use taxes are franchise fees, which are paid to various municipalities and counties (based on their ordinances) in order to use public rights of way for utility purposes. GSWC and BVESI bill these franchise fees to its customers based on a CPUC-authorized rate for each ratemaking area as applicable. These franchise fees, which are required to be paid regardless of GSWC’s or BVESI's ability to collect them from its customers, are accounted for on a gross basis. Franchise fees billed to customers and recorded as operating revenue were approximately $3.8 million, $4.0 million and $3.6 million for the years ended December 31, 2020, 2019 and 2018, respectively. When GSWC or BVESI act as an agent, and a tax is not required to be remitted if it is not collected from customers, the tax is accounted for on a net basis. As currently authorized by the CPUC, GSWC and BVESI record in revenues the difference between the adopted level of volumetric revenues as authorized by the CPUC for metered accounts (volumetric revenues) and the actual volumetric revenues recovered in customer rates. For GSWC, the difference is tracked under the Water Revenue Adjustment Mechanism (“WRAM”) regulatory accounts, and for BVESI the difference is tracked in the Base Revenue Requirement Adjustment Mechanism ("BRRAM") regulatory account. If this difference results in an under-collection of revenues, additional revenue is recorded only to the extent that the difference is expected to be collected within 24 months following the year in which they are recorded in accordance with Accounting Standards Codification ("ASC") Topic 980, Regulated Operations . ASUS's 50-year firm fixed-price contracts with the U.S. government are considered service concession arrangements under ASC 853 Service Concession Arrangements . Accordingly, the services under these contracts are accounted for under Topic 606 Revenue from Contracts with Customers and the water and/or wastewater systems are not recorded as Property, Plant and Equipment on Registrant’s balance sheet. For ASUS, performance obligations consist of (i) performing ongoing operation and maintenance of the water and/or wastewater systems and treatment plants for each military base served, and (ii) performing construction activities (including renewal and replacement capital work) on each military base served. The transaction price for each performance obligation is either delineated in, or initially derived from, the applicable 50-year contract and/or any subsequent contract modifications. Depending on the state in which operations are conducted, the Military Utility Privatization Subsidiaries are also subject to certain state non-income tax assessments which are accounted for on a gross basis and have been immaterial to date. The ongoing performance of operation and maintenance of the water and/or wastewater systems and treatment plants is viewed as a single performance obligation for each 50-year contract with the U.S. government. Registrant recognizes revenue for operations and maintenance fees monthly using the "right to invoice" practical expedient under ASC Topic 606. ASUS has a right to consideration from the U.S. government in an amount that corresponds directly to the value to the U.S. government of ASUS’s performance completed to-date. The contractual operations and maintenance fees are firm-fixed, and the level of effort or resources expended in the performance of the operations-and-maintenance-fees performance obligation is largely consistent over the 50-year term. Therefore, Registrant has determined that the monthly amounts invoiced for operations and maintenance performance are a fair reflection of the value transferred to the U.S. government. Invoices to the U.S. government for operations and maintenance service, as well as construction activities, are due upon receipt. ASUS's construction activities consist of various projects to be performed. Each of these projects' transaction prices are delineated either in the 50-year contract or through a specific contract modification for each construction project, which includes the transaction price for that project. Each construction project is viewed as a separate, single performance obligation. Therefore, it is generally unnecessary to allocate a construction transaction price to more than one construction performance obligation. Revenues for construction activities are recognized over time, with progress toward completion measured based on the input method using costs incurred relative to the total estimated costs (cost-to-cost method). Due to the nature of these construction projects, Registrant has determined the cost-to-cost input measurement to be the best method to measure progress towards satisfying its construction contract performance obligations, as compared to using an output measurement such as units produced. Changes in job performance, job site conditions, change orders and/or estimated profitability may result in revisions to costs and income for ASUS, and are recognized in the period in which any such revisions are determined. Pre-contract costs for ASUS, which consist of design and engineering labor costs, are deferred if recovery is probable, and are expensed as incurred if recovery is not probable. Deferred pre-contract costs have been immaterial to date. Contracted services revenues recognized during the years ended December 31, 2020, 2019 and 2018 and from performance obligations satisfied in previous periods were not material. Although GSWC and BVESI have a diversified base of residential, commercial, industrial and other customers, revenues derived from residential and commercial customers account for nearly 90% of total water revenues, and 90% of total electric revenues. The vast majority of ASUS's revenues are from the U.S. government. For the years ended December 31, 2020, 2019, and 2018, disaggregated revenues from contracts with customers by segment are as follows: (dollar in thousands) For The Year Ended December 31, 2020 For The Year Ended December 31, 2019 For The Year Ended December 31, 2018 Water: Tariff-based revenues $ 329,670 $ 305,244 298,818 CPUC-approved surcharges (cost-recovery activities) 3,736 4,322 2,962 Other 2,100 2,006 1,813 Water revenues from contracts with customers 335,506 311,572 303,593 WRAM under/(over)-collection (alternative revenue program) (4,869) 8,258 (8,335) Total water revenues 330,637 319,830 295,258 Electric: Tariff-based revenues 35,283 36,628 34,501 CPUC-approved surcharges (cost-recovery activities) 686 410 214 Electric revenues from contracts with customers 35,969 37,038 34,715 BRRAM under/(over)-collection (alternative revenue program) 1,055 2,510 (365) Total electric revenues 37,024 39,548 34,350 Contracted services: Water 74,898 59,868 62,273 Wastewater 45,684 54,623 44,935 Contracted services revenues from contracts with customers 120,582 114,491 107,208 Total revenues $ 488,243 $ 473,869 $ 436,816 The opening and closing balances of the receivable from the U.S. government, contract assets and contract liabilities from contracts with customers, which related entirely to ASUS, are as follows: (dollar in thousands) December 31, 2020 December 31, 2019 Unbilled receivables $ 14,924 $ 10,467 Receivable from the U.S. government $ 74,670 $ 64,819 Contract assets $ 10,257 $ 15,631 Contract liabilities $ 1,800 $ 11,167 Unbilled receivables and Receivable from the U.S. government represent receivables where the right to payment is conditional only by the passage of time. The increase in unbilled receivables as of December 31, 2020 as compared to December 31, 2019 was due to the completion in 2020 of construction project at Fort Riley, which will be collected in installments from the U.S. government over a 5-year period and government delays in issuing funding modifications at Fort Bliss for the recurring fixed monthly charges. Contract Assets - Contract assets are those of ASUS and consist of unbilled revenues recognized from work-in-progress construction projects where the right to payment is conditional on something other than the passage of time. The classification of this asset as current or noncurrent is based on the timing of when ASUS expects to bill these amounts. Contract Liabilities - Contract liabilities are those of ASUS and consist of billings in excess of revenue recognized. The classification of this liability as current or noncurrent is based on the timing of when ASUS expects to recognize revenue. Revenues for the year ended December 31, 2020 that were included in contract liabilities at the beginning of the period were $10.9 million. As of December 31, 2020, Registrant's aggregate remaining performance obligations, all of which are for the contracted services segment, was $3.2 billion. Registrant expects to recognize revenue on these remaining performance obligations over the remaining terms of each of the 50-year contracts, which range from 34 to 48 years. Each of the contracts with the U.S. government is subject to termination, in whole or in part, prior to the end of its 50-year term for the convenience of the U.S. government.

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2020
Regulated Operations [Abstract]
Regulatory Matters	Regulatory Matters In accordance with accounting principles for rate-regulated enterprises, Registrant records regulatory assets, which represent probable future recovery of costs from customers through the ratemaking process, and regulatory liabilities, which represent probable future refunds that are to be credited to customers through the ratemaking process. At December 31, 2020, Registrant had approximately $19.8 million of regulatory liabilities, net of regulatory assets, not accruing carrying costs. Of this amount, (i) $78.3 million of regulatory liabilities relates to the creation of an excess deferred income tax liability brought about by a lower federal income tax rate as a result of the Tax Cuts and Jobs Act that is expected to be refunded to customers (Note 11), (ii) $10.4 million relates to flow-through deferred income taxes including the gross-up portion on the deferred tax resulting from the excess deferred income tax regulatory liability (Note 11), and (iii) $66.6 million of regulatory assets relates to the underfunded position in Registrant's pension and other post-retirement obligations (excluding the two-way pension balancing accounts). The remainder relates to other items that do not provide for or incur carrying costs. Regulatory assets represent costs incurred by GSWC and BVESI for which either has received or expects to receive rate recovery in the future. In determining the probability of costs being recognized in other periods, GSWC and BVESI consider regulatory rules and decisions, past practices, and other facts or circumstances that would indicate if recovery is probable. If the CPUC determines that a portion of either GSWC’s or BVESI's assets are not recoverable in customer rates, the applicable entity must determine if it has suffered an asset impairment that requires it to write down the asset's value. Regulatory assets are offset against regulatory liabilities within each ratemaking area. Amounts expected to be collected or refunded in the next twelve months have been classified as current assets and current liabilities by ratemaking area. Regulatory assets, less regulatory liabilities, included in the consolidated balance sheets are as follows: December 31, (dollars in thousands) 2020 2019 GSWC Water Revenue Adjustment Mechanism, net of the Modified Cost Balancing Account $ 13,741 $ 22,535 Costs deferred for future recovery on Aerojet case 6,751 8,292 Pensions and other post-retirement obligations (Note 12) 65,576 40,693 Derivative unrealized loss (Note 5) — 3,171 COVID-19 memorandum account 4,119 — Other regulatory assets 10,670 23,662 Excess deferred income taxes (Note 11) (74,185) (79,886) Flow-through taxes, net (Note 11) (9,722) (12,439) Various refunds to customers (4,577) (8,478) Total GSWC $ 12,373 $ (2,450) BVESI Derivative unrealized loss (Note 5) 1,537 — Other regulatory assets 2,629 — Total AWR $ 16,539 $ (2,450) Alternative-Revenue Programs: GSWC records the difference between what it bills its water customers and that which is authorized by the CPUC using the Water Revenue Adjustment Mechanism ("WRAM") and the Modified Cost Balancing Account (“MCBA”) accounts approved by the CPUC. The over- or under-collection of the WRAM is aggregated with the MCBA over- or under-collection for the corresponding ratemaking area and bears interest at the current 90-day commercial-paper rate. During the year ended December 31, 2020, $14.7 million of pre-2020 WRAM/MCBA balances were recovered through surcharges. During 2020, GSWC recorded an additional $5.9 million net under-collection in the WRAM/MCBA. The majority of this balance represents an under-collection of supply costs incurred and recorded in the MCBA due to a higher volume of purchased water as compared to adopted. As of December 31, 2020, GSWC had an aggregated regulatory asset of $13.7 million, which is comprised of a $3.6 million over-collection in the WRAM accounts and a $17.3 million under-collection in the MCBA accounts. As required by the accounting guidance for alternative revenue programs, GSWC is required to collect its WRAM balances within 24 months following the year in which an under-collection is recorded. As of December 31, 2020, there were no WRAM under-collections that were estimated to be collected over more than 24 months. Costs Deferred for Future Recovery : The CPUC authorized a memorandum account to allow for the recovery of costs incurred by GSWC related to contamination lawsuits brought against Aerojet-General Corporation ("Aerojet") and the state of California. In July 2005, the CPUC authorized GSWC to recover approximately $21.3 million of the Aerojet litigation memorandum account, through a rate surcharge, which will continue for no longer than 20 years. Beginning in October 2005, a surcharge went into effect to begin amortizing the memorandum account over a 20-year period. Aerojet also agreed to reimburse GSWC $17.5 million, plus interest accruing from January 1, 2004, for GSWC’s past legal and expert costs, which is included in the Aerojet litigation memorandum account. The reimbursement of the $17.5 million is contingent upon the issuance of land use approvals for development in a defined area within Aerojet property in Eastern Sacramento County and the receipt of certain fees in connection with such development. It is management’s intention to offset any proceeds from the housing development by Aerojet in this area against the balance in this litigation memorandum account. At this time, management believes the full balance of the Aerojet litigation memorandum account will be collected either from customers or Aerojet. Pensions and Other Post-retirement Obligations : A regulatory asset has been recorded at December 31, 2020 and 2019 for the costs that would otherwise be charged to “other comprehensive income” within shareholders’ equity for the underfunded status of Registrant’s pension and other post-retirement benefit plans because the cost of these plans has historically been recovered through rates. As discussed in Note 12, as of December 31, 2020, Registrant’s underfunded position for these plans that have been recorded as a regulatory asset totaled $66.6 million. Registrant expects this regulatory asset to be recovered through rates in future periods. The CPUC has authorized GSWC and BVESI to each use two-way balancing accounts to track differences between the forecasted annual pension expenses adopted in their respective customer rates and the actual annual expense to be recorded in accordance with the accounting guidance for pension costs. The two-way balancing accounts bear interest at the current 90-day commercial paper rate. As of December 31, 2020, GSWC has a $1.0 million over-collection related to the general office and water regions, and BVESI has a $206,000 over-collection in its two-way balancing account. COVID-19 Memorandum Accounts : The CPUC has approved GSWC's and BVESI's requests to activate memorandum accounts, such as a Catastrophic Event Memorandum Account ("CEMA"), for the impact of the COVID-19 pandemic. GSWC and BVESI have suspended service disconnections for nonpayment as required by the CPUC. Costs incurred by GSWC and BVESI in response to the COVID-19 pandemic, including bad debt expense in excess of what is included in their respective revenue requirements, are being included in these memorandum accounts for future recovery. As of December 31, 2020, GSWC and BVESI recorded $4.1 million and $295,000, respectively, in COVID-19-related incremental costs as regulatory assets as GSWC and BVESI believe these costs are probable of recovery. Other Regulatory Assets:

Utility Plant and Intangible As

Utility Plant and Intangible Assets	12 Months Ended
	Dec. 31, 2020
Utility Plant and Intangible Assets
Utility Plant and Intangible Assets	Utility Plant and Intangible Assets The following table shows Registrant’s utility plant (regulated utility plant and non-regulated utility property) by major asset class: AWR GSWC (dollars in thousands) 2020 2019 2020 2019 Water Land $ 18,234 $ 18,066 $ 18,234 $ 18,066 Intangible assets 28,906 28,578 28,906 28,578 Source of water supply 92,166 91,685 92,166 91,685 Pumping 190,901 178,058 190,901 178,058 Water treatment 81,272 78,048 81,272 78,048 Transmission and distribution 1,277,361 1,219,285 1,277,361 1,219,285 Other 128,877 117,276 95,562 86,722 1,817,717 1,730,996 1,784,402 1,700,442 Electric (Note 20) Transmission and distribution 87,461 84,018 — 84,018 Generation 12,583 12,583 — 12,583 Other (1) 12,463 11,824 — 11,824 112,507 108,425 — 108,425 Less — accumulated depreciation (568,326) (543,263) (502,283) (531,801) Construction work in progress 150,145 119,547 118,370 117,676 Net utility plant $ 1,512,043 $ 1,415,705 $ 1,400,489 $ 1,394,742 (1) Includes intangible assets of $1.2 million for the years ended December 31, 2020 and 2019 for studies performed in association with the electric segment. As of December 31, 2020 and 2019, intangible assets consist of the following: Weighted Average Amortization AWR December 31, GSWC December 31, (dollars in thousands) Period 2020 2019 2020 2019 Intangible assets : Conservation programs 3 years $ 9,486 $ 9,486 $ 9,486 $ 9,486 Water and service rights (2) 30 years 8,694 8,695 8,124 8,124 Water planning studies 14 years 12,141 11,808 10,898 11,808 Total intangible assets 30,321 29,989 28,508 29,418 Less — accumulated amortization (24,460) (24,309) (24,305) (24,166) Intangible assets, net of amortization $ 5,861 $ 5,680 $ 4,203 $ 5,252 Intangible assets not subject to amortization (3) $ 399 $ 402 $ 399 $ 402 (2) Includes intangible assets of $571,000 for contracted services included in "Other Property and Investments" on the consolidated balance sheets as of December 31, 2020 and 2019. (3) The intangible assets not subject to amortization primarily consist of organization and consent fees. For the years ended December 31, 2020, 2019 and 2018, amortization of intangible assets was $654,000, $1.3 million and $1.1 million, respectively, for both AWR and GSWC. Estimated future consolidated amortization expense related to intangible assets for the succeeding five years are (in thousands): Amortization 2021 $ 142 2022 114 2023 114 2024 74 2025 — Total $ 444 Asset Retirement Obligations : The following is a reconciliation of the beginning and ending aggregate carrying amount of asset retirement obligations, which are included in “Other Credits” on the balance sheets as of December 31, 2020 and 2019: (dollars in thousands) GSWC Obligation at December 31, 2018 $ 5,228 Additional liabilities incurred 271 Liabilities settled (173) Accretion 86 Revision of previous estimates $ 3,451 Obligation at December 31, 2019 $ 8,863 Additional liabilities incurred 165 Liabilities settled (58) Accretion 350 Obligation at December 31, 2020 $ 9,320 Revision of previous estimates reflect updated estimated costs for the retirement of wells, which GSWC is legally required to cap at the time of removal. Wells have an estimated useful life of 50 years.

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives Instruments	Derivative Instruments BVESI purchases power under long-term contracts at a fixed cost over three These long-term contracts are subject to the accounting guidance for derivatives and require mark-to-market derivative accounting. Among other things, the CPUC also authorized BVESI to establish a regulatory asset and liability memorandum account to offset the mark-to-market entries required by the accounting guidance. Accordingly, all unrealized gains and losses generated from these purchased power contracts are deferred on a monthly basis into a non-interest bearing regulatory memorandum account that tracks the changes in fair value of the derivative throughout the term of the contract. As a result, these unrealized gains and losses do not impact Registrant’s earnings. As of December 31, 2020, there was a $1.5 million unrealized loss in the memorandum account, with a corresponding unrealized loss liability for the three As previously discussed in Note 1, the accounting guidance for fair value measurements establishes a framework for measuring fair value and requires fair value measurements to be classified and disclosed in one of three levels. Registrant’s valuation model utilizes various inputs that include quoted market prices for energy over the duration of the contracts. The market prices used to determine the fair value for these derivative instruments were estimated based on independent sources such as broker quotes and publications that are not observable in or corroborated by the market. When such inputs have a significant impact on the measurement of fair value, the instrument is categorized as Level 3. Accordingly, the valuation of the derivatives on Registrant’s purchased power contracts have been classified as Level 3 for all periods presented. The following table presents changes in the fair value of BVESI’s derivatives for the years 2020 and 2019: (dollars in thousands) 2020 2019 Balance, at beginning of the period $ (3,171) $ (311) Unrealized (loss) gain on purchased power contracts 1,634 (2,860) Balance, at end of the period $ (1,537) $ (3,171)

Military Privatization

Military Privatization	12 Months Ended
	Dec. 31, 2020
Military Privatization
Military Privatization	Military Privatization Each of the Military Utility Privatization Subsidiaries have entered into a service contract(s) with the U.S. government to operate and maintain, as well as perform construction activities to renew and replace, the water and/or wastewater systems at a military base or bases. The amounts charged for these services are based upon the terms of the 50-year contract between the Military Utility Privatization Subsidiaries and the U.S. government. Under the terms of each of these agreements, the Military Utility Privatization Subsidiaries agree to operate and maintain the water and/or wastewater systems for: (i) a monthly net fixed-price for operation and maintenance, and (ii) an amount to cover renewal and replacement capital work. In addition, these contracts may also include firm, fixed-priced initial capital upgrade projects to upgrade the existing infrastructure. Contract modifications are also issued for other necessary capital upgrades to the existing infrastructure approved by the U.S. government. Under the terms of each of these contracts, prices are subject to an economic price adjustment ("EPA") provision, on an annual basis. Prices may also be equitably adjusted for changes in law and other circumstances. ASUS is permitted to file, and has filed, requests for equitable adjustment. Each of the contracts may be subject to termination, in whole or in part, prior to the end of the 50-year term for convenience of the U.S. government or as a result of default or nonperformance by a Military Utility Privatization Subsidiary. ASUS has experienced delays in receiving EPAs as provided for under its 50-year contracts. Because of the delays, EPAs, when finally approved, are retroactive. During 2020, the U.S. government approved EPAs at seven of the bases served. In some cases, these EPAs included retroactive operation and maintenance management fees for prior periods. For the years ended December 31, 2020 and 2019, retroactive operation and maintenance management fees related to prior periods were immaterial.

Earnings Per Share and Capital

Earnings Per Share and Capital Stock	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share and Capital Stock	Earnings Per Share and Capital Stock In accordance with the accounting guidance for participating securities and earnings per share (“EPS”), Registrant uses the “two-class” method of computing EPS. The “two-class” method is an earnings allocation formula that determines EPS for each class of common stock and participating security. AWR has participating securities related to restricted stock units that earn dividend equivalents on an equal basis with AWR’s Common Shares that have been issued under AWR’s 2016 employee plans and the 2003 and 2013 directors' plans. In applying the “two-class” method, undistributed earnings are allocated to both common shares and participating securities. The following is a reconciliation of Registrant’s net income and weighted average Common Shares outstanding for calculating basic net income per share: Basic: For The Years Ended December 31, (in thousands, except per share amounts) 2020 2019 2018 Net income $ 86,425 $ 84,342 $ 63,871 Less: (a) Distributed earnings to common shareholders 47,206 42,702 38,937 Distributed earnings to participating securities 158 180 204 Undistributed earnings 39,061 41,460 24,730 (b) Undistributed earnings allocated to common shareholders 38,930 41,285 24,601 Undistributed earnings allocated to participating securities 131 175 129 Total income available to common shareholders, basic (a)+(b) $ 86,136 $ 83,987 $ 63,538 Weighted average Common Shares outstanding, basic 36,880 36,814 36,733 Basic earnings per Common Share $ 2.34 $ 2.28 $ 1.73 Diluted EPS is based upon the weighted average number of Common Shares, including both outstanding shares and shares potentially issuable in connection with restricted stock units granted under AWR’s 2016 employee plans, and the 2003 and 2013 directors' plans, and net income. At December 31, 2020, there were also 127,298 restricted stock units outstanding, including performance shares awarded to officers of the Registrant. The following is a reconciliation of Registrant’s net income and weighted average Common Shares outstanding for calculating diluted net income per share: Diluted: For The Years Ended December 31, (in thousands, except per share amounts) 2020 2019 2018 Common shareholders earnings, basic $ 86,136 $ 83,987 $ 63,538 Undistributed earnings for dilutive stock options and restricted stock units 131 175 129 Total common shareholders earnings, diluted $ 86,267 $ 84,162 $ 63,667 Weighted average Common Shares outstanding, basic 36,880 36,814 36,733 Stock-based compensation (1) 115 150 203 Weighted average Common Shares outstanding, diluted 36,995 36,964 36,936 Diluted earnings per Common Share $ 2.33 $ 2.28 $ 1.72 (1) In applying the treasury stock method of reflecting the dilutive effect of outstanding stock-based compensation in the calculation of diluted EPS, 127,298 restricted stock units, including performance awards, at December 31, 2020 were deemed to be outstanding in accordance with accounting guidance on earnings per share. During the years ended December 31, 2020, 2019 and 2018, AWR issued Common Shares totaling 42,489, 88,772 and 44,906, respectively, under AWR's employee stock incentive plans and the non-employee directors' plans. In addition, during the years ended December 31, 2020, 2019 and 2018, AWR issued 1,800, 30,998 and 32,142 Common Shares for approximately $30,000, $519,000 and $546,000, respectively, as a result of the exercise of stock options. During 2020, 2019 and 2018, no cash proceeds received by AWR as a result of the exercise of stock options were distributed to any of AWR's subsidiaries. AWR has not issued any Common Shares during 2020, 2019 and 2018 under AWR's Common Share Purchase and Dividend Reinvestment Plan ("DRP") and the 401(k) Plan. Shares reserved for the 401(k) Plan are in relation to AWR’s matching contributions and investment by participants. As of December 31, 2020, there were 1,055,948 and 387,300 Common Shares authorized for issuance directly by AWR but unissued under the DRP and the 401(k) Plan, respectively. During the years ended December 31, 2020 and 2018, GSWC issued five and nineteen additional Common Shares to AWR for $60 million and 47.5 million, respectively. The majority of the proceeds from these stock issuances were used by GSWC to pay down its intercompany borrowings from AWR. The CPUC requires GSWC to pay down all intercompany borrowings from AWR within a 24-month period. No shares were issued by GSWC during 2019. During the years ended December 31, 2020, 2019 and 2018, AWR and GSWC made payments to taxing authorities on employees' behalf for shares withheld related to net share settlements. These payments are included in the stock-based compensation caption of the statements of equity. GSWC’s outstanding common shares are owned entirely by its parent, AWR. To the extent GSWC does not reimburse AWR for stock-based compensation awarded under various stock compensation plans, such amounts increase the value of GSWC’s common shareholder’s equity.

Dividend Limitations

Dividend Limitations	12 Months Ended
	Dec. 31, 2020
Disclosure of Restrictions on Dividends, Loans and Advances Disclosure [Abstract]
Dividend Limitations	Dividend LimitationsGSWC is subject to contractual restrictions on its ability to pay dividends. GSWC’s maximum ability to pay dividends is restricted by certain Note Agreements to the sum of $21.0 million plus 100% of consolidated net income from various dates plus the aggregate net cash proceeds received from capital stock offerings or other instruments convertible into capital stock from various dates. Under the most restrictive of the Note Agreements, $576.4 million was available to pay dividends to AWR as of December 31, 2020. GSWC is also prohibited from paying dividends if, after giving effect to the dividend, its total indebtedness to capitalization ratio (as defined) would be more than 0.6667-to-1. Dividends in the amount of $22.5 million, $20.2 million and $68.9 million were paid to AWR by GSWC during the years ended December 31, 2020, 2019 and 2018, respectively.  The ability of AWR, GSWC, BVESI and ASUS to pay dividends is also restricted by California law. Under California law, AWR, GSWC, BVESI and ASUS are each permitted to distribute dividends to its shareholders so long as the Board of Directors determines, in good faith, that either: (i) the value of the corporation’s assets equals or exceeds the sum of its total liabilities immediately after the dividend, or (ii) its retained earnings equals or exceeds the amount of the distribution.  Under the least restrictive of the California tests, approximately $641.7 million was available to pay dividends to AWR’s shareholders at December 31, 2020. Approximately $583.3 million was available for GSWC to pay dividends to AWR at December 31, 2020.

Bank Debt

Bank Debt	12 Months Ended
	Dec. 31, 2020
Bank Debt
Bank Debt	Bank Debt AWR currently has access to a $200.0 million credit facility expiring in May 2023 in order to provide funds to GSWC and ASUS in support of their operations on terms that are similar to that of the credit facility. During 2019 and 2020, AWR amended the credit facility to temporarily increase the borrowing capacity as high as $260.0 million in order to meet the operational needs of GSWC and ASUS. Following the issuance of GSWC’s long-term debt in July 2020, AWR reduced the aggregate borrowing capacity to $200.0 million pursuant to the terms of that credit facility agreement. At December 31, 2020, there was $134.2 million outstanding under the credit facility. The aggregate effective amount that may be outstanding under letters of credit is $25.0 million. AWR has obtained letters of credit, primarily for GSWC, in the aggregate amount of $455,000 at fees of 0.65%. Letters of credit outstanding reduce the amount that may be borrowed under the revolving credit facility. AWR is not required to maintain any compensating balances. Loans may be obtained under this credit facility at the option of AWR and bear interest at rates based on credit ratings and Euro rate margins. In June 2020, Standard and Poor’s Global Ratings (“S&P”) affirmed an A+ credit rating with a stable outlook on both AWR and GSWC. S&P’s debt ratings range from AAA (highest possible) to D (obligation is in default). In June 2020, Moody's Investors Service ("Moody's") also reaffirmed its A2 rating with a stable outlook for GSWC. Effective July 1, 2020, BVESI has access to a 3-year, $35.0 million revolving credit facility. As of December 31, 2020, there was $20.2 million outstanding under this facility. Borrowings made under this facility support the electric segment's operations and capital expenditures. Under the terms of the credit agreement, BVESI has the option to request an increase in the facility by an additional $15 million. Registrant’s borrowing activities (excluding letters of credit) for the years ended December 31, 2020 and 2019 were as follows: December 31, (in thousands, except percent) 2020 2019 Balance Outstanding at December 31, $ 134,200 $ 205,000 Interest Rate at December 31, 1.19% ~ 1.90% 2.44 % Average Amount Outstanding $ 162,995 $ 167,392 Weighted Average Annual Interest Rate 1.47 % 2.88 % Maximum Amount Outstanding $ 249,200 $ 205,500 All of the letters of credit are issued pursuant to AWR's revolving credit facility. The revolving credit facility contains restrictions on prepayments, disposition of property, mergers, liens and negative pledges, indebtedness and guaranty obligations, transactions with affiliates, minimum interest coverage requirements, a maximum debt to capitalization ratio and a minimum debt rating. Pursuant to the credit agreement, AWR must maintain a minimum interest coverage ratio of 3.25 times interest expense, a maximum total funded debt ratio of 0.65 to 1.00 and a minimum Moody’s Investor Service or S&P debt rating of Baa3 or BBB-, respectively. As of December 31, 2020, 2019 and 2018, AWR was in compliance with these requirements. As of December 31, 2020, AWR had an interest coverage ratio of 7.74 times interest expense, a debt ratio of 0.47 to 1.00 and a debt rating of A+ by S&P.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Registrant’s long-term debt consists of notes and debentures of GSWC. Registrant summarizes its long-term debt in the Statements of Capitalization. GSWC does not currently have any outstanding mortgages or other encumbrances on its properties. On July 8, 2020, GSWC completed the issuance of unsecured private placement notes totaling $160.0 million. In connection with this financing, GSWC issued (i) $ $85.0 million aggregate principal amount of Series A Senior Notes at a coupon rate of 2.17% due July 8, 2030, and (ii) $75.0 million aggregate principal amount of Series B Senior Notes at a coupon rate of 2.90% due July 8, 2040. Interest on the Notes is payable semiannually. The Notes are unsecured and rank equally with GSWC’s unsecured and unsubordinated debt. GSWC may, at its option, redeem all or portions of the Notes at any time upon written notice, subject to payment of a make-whole premium based on 50 basis points above the applicable treasury yield. The make-whole premiums and covenant requirements under these notes are similar to the terms of the $15.0 million 3.45% senior private placement notes due in 2029 and the $40.0 million 5.87% senior private placement notes due in 2028. Pursuant to the terms of each of these notes, GSWC must maintain a total indebtedness to capitalization ratio (as defined) of less than 0.6667-to-1 and a total indebtedness to earnings before income taxes, depreciation and amortization ("EBITDA") of less than 8-to-1. As of December 31, 2020, GSWC had a total indebtedness to capitalization ratio of 0.4306-to-1 and a total indebtedness to EBITDA of 3.1-to-1. GSWC's private placement 9.56% notes issued in the amount of $28 million and due in 2031 contain restrictions on the payment of dividends, minimum interest coverage requirements, a maximum total indebtedness to capitalization ratio and a negative pledge. Pursuant to the terms of these notes, GSWC must maintain a minimum interest coverage ratio of two times interest expense. As of December 31, 2020, GSWC had an interest coverage ratio of over four times interest expense. These notes can be redeemed, in whole or in part, at the option of GSWC subject to redemption schedules embedded in the agreement. The 9.56% notes are subject to a make-whole premium based on 55 basis points above the applicable Treasury Yield if redeemed prior to May 2021. After May 2021, the maximum redemption premium is 3% of par value. In October 2009, GSWC entered into an agreement with the California Department of Public Health (“CDPH”) whereby CDPH agreed to provide funds to GSWC of up to $9.0 million under the American Recovery and Reinvestment Act. Proceeds from the funds received were used to reimburse GSWC for capital costs incurred to install water meters to convert customers in GSWC’s Arden-Cordova district from non-metered service to metered service. GSWC received a total of $8.6 million in reimbursements from the CDPH, half of which was recorded as a contribution in aid of construction and the other half as long-term debt in accordance with the terms of the agreement. The loan portion bears interest at a rate of 2.5% and is payable over 20 years beginning in 2013. A surcharge to recover from customers the debt service cost on this loan was approved by the CPUC and implemented in 2013. Annual maturities of all long-term debt at December 31, 2020 are as follows (in thousands): 2021 $ 358 2022 382 2023 406 2024 430 2025 449 Thereafter 442,246 Total $ 444,271

Taxes on Income

Taxes on Income	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Taxes on Income	Taxes on Income Registrant records deferred income taxes for temporary differences pursuant to the accounting guidance that addresses items recognized for income tax purposes in a different period from when these items are reported in the financial statements. These items include differences in net asset basis (primarily related to differences in depreciation lives and methods, and differences in capitalization methods) and the treatment of certain regulatory balancing accounts and construction contributions and advances. The accounting guidance for income taxes requires that rate-regulated enterprises record deferred income taxes and offsetting regulatory liabilities and assets for temporary differences where the rate regulator has prescribed flow-through treatment for ratemaking purposes (Note 3). Deferred investment tax credits (“ITC”) are amortized ratably to deferred tax expense over the remaining lives of the property that gave rise to these credits. GSWC is included in both AWR’s consolidated federal income tax and its combined California state franchise tax returns. The impact of California’s unitary apportionment on the amount of AWR’s California income tax liability is a function of both the profitability of AWR’s non-California activities and the proportion of AWR’s California sales to its total sales. GSWC’s income tax expense is computed as if GSWC were autonomous and separately files its income tax returns, which is consistent with the method adopted by the CPUC in setting GSWC’s customer rates. On December 22, 2017, the Tax Cuts and Jobs Act (the "Tax Act") was signed into federal law. The provisions of this major tax reform were generally effective on January 1, 2018. Among its significant provisions, the Tax Act (i) reduced the federal corporate income tax rate from 35% to 21%; (ii) eliminated bonus depreciation for regulated utilities, while allowing 100% expensing for the cost of qualified property for non-regulated businesses; (iii) eliminated the provision that treated contributions in aid of construction provided to regulated water utilities as non-taxable; (iv) eliminated the domestic production activities deduction, and (v) limits the amount of net interest that can be deducted; however, this limitation is not applicable to regulated utilities and, therefore has not had, nor is it anticipated to have, a material impact to Registrant’s ability to deduct net interest. Pursuant to ASC Topic 740, "Income Taxes" , the effects of the Tax Act were recognized in 2017, the year in which the tax law was enacted, and required AWR and GSWC to record an adjustment to reflect the impact of the reduction in the corporate income tax rate from 35% to 21% % on its cumulative deferred income-tax balances and its tax-related regulatory assets/liabilities. The significant components of the deferred tax assets and liabilities as reflected in the balance sheets at December 31, 2020 and 2019 are: AWR GSWC December 31, December 31, (dollars in thousands) 2020 2019 2020 2019 Deferred tax assets: Regulatory-liability-related (1) $ 32,640 $ 33,080 $ 30,782 $ 33,080 Contributions and advances 6,390 5,777 6,771 6,158 Other 6,092 5,792 6,663 6,618 Total deferred tax assets $ 45,122 $ 44,649 $ 44,216 $ 45,856 Deferred tax liabilities: Fixed assets $ (146,688) $ (144,444) $ (141,422) $ (147,759) Regulatory-asset-related: depreciation and other (22,205) (20,641) (21,060) (20,641) Balancing and memorandum accounts (non-flow-through) (7,401) (4,868) (6,315) (5,262) Total deferred tax liabilities (176,294) (169,953) (168,797) (173,662) Accumulated deferred income taxes - net $ (131,172) $ (125,304) $ (124,581) $ (127,806) (1) Primarily represents the gross-up portion of the deferred income tax (on the excess-deferred-tax regulatory liability) brought about by the Tax Act’s reduction in the federal income tax rate. The current and deferred components of income tax expense are as follows: AWR Year Ended December 31, (dollars in thousands) 2020 2019 2018 Current Federal $ 19,240 $ 12,507 $ 17,252 State 6,714 5,540 6,538 Total current tax expense $ 25,954 $ 18,047 $ 23,790 Deferred Federal $ 1,814 $ 6,407 $ (4,334) State 429 216 (1,439) Total deferred tax (benefit) expense 2,243 6,623 (5,773) Total income tax expense $ 28,197 $ 24,670 $ 18,017 GSWC Year Ended December 31, (dollars in thousands) 2020 2019 2018 Current Federal $ 14,674 $ 9,616 $ 14,488 State 5,849 5,480 5,932 Total current tax expense $ 20,523 $ 15,096 $ 20,420 Deferred Federal $ 949 $ 4,924 $ (5,531) State 232 157 (1,286) Total deferred tax (benefit) expense 1,181 5,081 (6,817) Total income tax expense $ 21,704 $ 20,177 $ 13,603 The AWR and GSWC effective tax rates differ from the federal statutory tax rate primarily due to (i) state taxes; (ii) permanent differences including the excess tax benefits from share-based payments, which were reflected in the income statements and resulted in a reduction to income tax expense; (iii) amortization, commencing in 2018, of the excess deferred income tax liability brought about by the lower federal corporate income tax rate, and (iv) differences between book and taxable income that are treated as flow-through adjustments in accordance with regulatory requirements (principally from plant, rate-case, and compensation expenses). As a regulated utility, GSWC treats certain temporary differences as flow-through in computing its income tax expense consistent with the income tax method used in its CPUC-jurisdiction ratemaking. Flow-through items either increase or decrease tax expense and thus impact the ETR. The reconciliations of the effective tax rates to the federal statutory rate are as follows: AWR Year Ended December 31, (dollars in thousands) 2020 2019 2018 Federal taxes on pretax income at statutory rate $ 24,071 $ 22,872 $ 17,196 Increase (decrease) in taxes resulting from: State income tax, net of federal benefit 5,764 4,758 3,693 Excess deferred tax amortization (1,550) (1,579) (2,101) Flow-through on fixed assets 1,056 1,244 429 Flow-through on removal costs (1,031) (1,582) (1,445) Investment tax credit (71) (71) (69) Other – net (42) (972) 314 Total income tax expense from operations $ 28,197 $ 24,670 $ 18,017 Pretax income from operations $ 114,622 $ 109,012 $ 81,888 Effective income tax rate 24.6 % 22.6 % 22.0 % GSWC Year Ended December 31, (dollars in thousands) 2020 2019 2018 Federal taxes on pretax income at statutory rate $ 18,202 $ 18,236 $ 12,939 Increase (decrease) in taxes resulting from: State income tax, net of federal benefit 4,920 4,656 3,335 Excess deferred tax amortization (1,477) (1,579) (2,101) Flow-through on fixed assets 1,042 1,244 429 Flow-through on removal costs (1,026) (1,582) (1,445) Investment tax credit (71) (71) (69) Other – net 114 (727) 515 Total income tax expense from operations $ 21,704 $ 20,177 $ 13,603 Pretax income from operations $ 86,675 $ 86,840 $ 61,615 Effective income tax rate 25.0 % 23.2 % 22.1 % AWR and GSWC had no unrecognized tax benefits at December 31, 2020, 2019 and 2018. Registrant’s policy is to classify interest on income tax over/underpayments in interest income/expense and penalties in “other operating expenses.” Registrant did not have any material interest receivables/payables from/to taxing authorities as of December 31, 2020 and 2019, nor did it recognize any material interest income/expense or accrue any material tax-related penalties during the years ended December 31, 2020, 2019 and 2018. Registrant files federal, California and various other state income tax returns. AWR's 2017 - 2019 tax years remain subject to examination by the Internal Revenue Service. AWR filed refund claims with the California Franchise Tax Board ("FTB") for the 2005 through 2008 tax years in connection with the matters reflected on the federal refund claims along with other state tax items. The FTB continues to review the 2005 - 2008 refund claims. The 2009 - 2019 tax years remain subject to examination by the FTB.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans Pension and Post-Retirement Medical Plans : Registrant maintains a defined benefit pension plan (the “Pension Plan”) that provides eligible employees (those aged 21 and older, hired before January 1, 2011) monthly benefits upon retirement based on average salaries and length of service. The eligibility requirement to begin receiving these benefits is 5 years of vested service. The normal retirement benefit is equal to 2% of the 5 highest consecutive years’ average earnings multiplied by the number of years of credited service, up to a maximum of 40, reduced by a percentage of primary Social Security benefits. There is also an early retirement option. Annual contributions are made to the Pension Plan, which comply with the funding requirements of the Employee Retirement Income Security Act (“ERISA”). At December 31, 2020, Registrant had 935 participants in the Pension Plan. Employees hired or rehired after December 31, 2010 are eligible to participate in a defined contribution plan. Registrant's existing 401(k) Investment Incentive Program was amended to include this defined contribution plan. Under this plan, Registrant provides a contribution ranging from 3% to 5.25% of eligible pay each pay period into investment vehicles offered by the plan’s trustee. Full vesting under this plan occurs upon 3 years of service. Employees hired before January 1, 2011 continue to participate in and accrue benefits under the terms of the Pension Plan. Registrant also provides post-retirement medical benefits for all active employees hired before February of 1995 through a medical insurance plan. Eligible employees, who retire prior to age 65, and/or their spouses, are able to retain the benefits under the plan for active employees until reaching age 65. Eligible employees upon reaching age 65, and those eligible employees retiring at or after age 65, and/or their spouses, receive coverage through a Medicare supplement insurance policy paid for by Registrant subject to an annual cap limit. Registrant’s post-retirement medical plan does not provide prescription drug benefits to Medicare-eligible employees and is not affected by the Medicare Prescription Drug Improvement and Modernization Act of 2003. In accordance with the accounting guidance for the effects of certain types of regulation, Registrant has established a regulatory asset for its underfunded position in its pension and post-retirement medical plans that is expected to be recovered through rates in future periods. The changes in actuarial gains and losses, prior service costs and transition assets or obligations pertaining to the regulatory asset are recognized as an adjustment to the regulatory asset account as these amounts are recognized as components of net periodic pension cost each year and in the rate-making process. The following table sets forth the Pension Plan’s and post-retirement medical plan’s funded status and amounts recognized in Registrant’s balance sheets and the components of net pension cost and accrued liability at December 31, 2020 and 2019: Pension Benefits Post-Retirement Medical (dollars in thousands) 2020 2019 2020 2019 Change in Projected Benefit Obligation: Projected benefit obligation at beginning of year $ 231,852 $ 196,082 $ 7,395 $ 7,886 Service cost 5,558 4,441 171 186 Interest cost 7,880 8,527 208 285 Actuarial (gain) loss 35,453 29,784 (1,604) (538) Benefits/expenses paid (7,957) (6,982) (264) (424) Projected benefit obligation at end of year $ 272,786 $ 231,852 $ 5,906 $ 7,395 Changes in Plan Assets: Fair value of plan assets at beginning of year $ 192,477 $ 162,529 $ 11,271 $ 10,010 Actual return on plan assets 24,909 33,018 1,307 1,685 Employer contributions 3,718 3,913 269 170 Benefits/expenses paid (7,957) (6,983) (534) (594) Fair value of plan assets at end of year $ 213,147 $ 192,477 $ 12,313 $ 11,271 Funded Status: Net amount recognized as accrued pension cost $ (59,639) $ (39,375) $ 6,407 $ 3,876 The increase in the underfunded status of the pension was due primarily to a decrease in the discount rate, which decreased from 3.43% as of December 31, 2019 to 2.55% as of December 31, 2020 as noted in the following tables. Pension Benefits Post-Retirement (dollars in thousands) 2020 2019 2020 2019 Amounts recognized on the balance sheets: Non-current assets $ — $ — $ 6,407 $ 3,876 Current liabilities — — — — Non-current liabilities (59,639) (39,375) — — Net amount recognized $ (59,639) $ (39,375) $ 6,407 $ 3,876 Amounts recognized in regulatory assets consist of: Prior service cost (credit) $ 2,757 $ 3,191 $ — $ — Net (gain) loss 57,716 37,309 (6,855) (5,432) Regulatory assets (liabilities) 60,473 40,500 (6,855) (5,432) Unfunded accrued pension cost (834) (1,125) 448 1,556 Net liability (asset) recognized $ 59,639 $ 39,375 $ (6,407) $ (3,876) Changes in plan assets and benefit obligations recognized in regulatory assets: Regulatory asset at beginning of year $ 40,500 $ 35,213 $ (5,432) $ (4,459) Net loss (gain) 22,343 7,140 (2,400) (1,775) New prior service cost — — — — Amortization of prior service (cost) credit (435) (434) — — Amortization of net gain (loss) (1,935) (1,419) 977 802 Total change in regulatory asset 19,973 5,287 (1,423) (973) Regulatory asset (liability) at end of year $ 60,473 $ 40,500 $ (6,855) $ (5,432) Net periodic pension costs $ 4,010 $ 4,447 $ (1,108) $ (779) Change in regulatory asset 19,973 5,287 (1,423) (973) Total recognized in net periodic pension cost and regulatory asset (liability) $ 23,983 $ 9,734 $ (2,531) $ (1,752) Additional year-end information for plans with an accumulated benefit obligation in excess of plan assets: Projected benefit obligation $ 272,786 $ 231,852 $ 5,906 $ 7,395 Accumulated benefit obligation $ 253,108 $ 215,996 N/A N/A Fair value of plan assets $ 213,147 $ 192,477 $ 12,313 $ 11,271 Weighted-average assumptions used to determine benefit obligations at December 31: Discount rate 2.55 % 3.43 % 2.20 % 3.12 % Rate of compensation increase * * N/A N/A • Age-graded ranging from 3.0% to 8.0%. The components of net periodic pension and post-retirement benefits cost, before allocation to the overhead pool, for 2020, 2019 and 2018 are as follows: Pension Benefits Post-Retirement (dollars in thousands, except percent) 2020 2019 2018 2020 2019 2018 Components of Net Periodic Benefits Cost: Service cost $ 5,558 $ 4,441 $ 5,342 $ 171 $ 186 $ 218 Interest cost 7,880 8,527 7,646 208 285 292 Expected return on plan assets (11,798) (10,374) (11,172) (510) (449) (493) Amortization of prior service cost (credit) 435 434 — — — Amortization of actuarial (gain) loss 1,935 1,419 1,254 (977) (801) (769) Net periodic pension cost under accounting standards $ 4,010 $ 4,447 $ 3,070 $ (1,108) $ (779) $ (752) Regulatory adjustment (483) (593) — — — — Total expense recognized, before surcharges and allocation to overhead pool $ 3,527 $ 3,854 $ 3,070 $ (1,108) $ (779) $ (752) Weighted-average assumptions used to determine net periodic cost: Discount rate 3.43 % 4.43 % 3.76 % 3.12 % 4.20 % 3.52 % Expected long-term return on plan assets 6.25 % 6.50 % 6.50 % * * * Rate of compensation increase ** ** ** N/A N/A N/A *6.0% for union plan and 4.2% for non-union (net of income taxes) in 2020, 2019 and 2018. ** Age-graded ranging from 3.0% to 8.0%. Regulatory Adjustment : The CPUC authorized GSWC and BVESI to track differences between the forecasted annual pension expenses adopted in rates and the actual annual expenses to be recorded in accordance with the accounting guidance for pension costs in a two-way pension balancing account. During the year ended December 31, 2020 and 2019, GSWC's actual expense was higher than the amounts included in customer rates by $483,000and $593,000, respectively. In 2018, GSWC's actual expense was lower than the amounts included in water rates by $1.7 million. The cumulative amount recorded in GSWC's two-way pension balancing account is included within the pensions and other post-retirement obligations regulatory asset discussed in Note 3. During the years ended December 31, 2020, 2019 and 2018, BVESI's actual expense was lower than the amounts included in electric rates by $200,000, $205,000 and $271,000, respectively. These over-collections were recorded as a reduction to electric revenues. Plan Funded Status : The Pension Plan was underfunded at December 31, 2020 and 2019. Registrant’s market related value of plan assets is equal to the fair value of plan assets. Past volatile market conditions have affected the value of GSWC’s trust established to fund its future long-term pension benefits. These benefit plan assets and related obligations are measured annually using a December 31 measurement date. Changes in the Pension Plan’s funded status will affect the assets and liabilities recorded on the balance sheet in accordance with accounting guidance on employers’ accounting for defined benefit pension and other post-retirement plans. Due to Registrant’s regulatory recovery treatment, the recognition of the underfunded status for the Pension Plan has been offset by a regulatory asset pursuant to guidance on the accounting for the effects of certain types of regulation. Plan Assets : The assets of the pension and post-retirement medical plans are managed by a third party trustee. The investment policy allocation of the assets in the trust was approved by Registrant’s Administrative Committee (the “Committee”) for the pension and post-retirement medical funds, which has oversight responsibility for all retirement plans. The primary objectives underlying the investment of the pension and post-retirement plan assets are: (i) attempt to maintain a fully funded status with a cushion for unexpected developments, possible future increases in expense levels and/or a reduction in the expected return on investments; (ii) seek to earn long-term returns that compare favorably to appropriate market indexes, peer group universes and the policy asset allocation index; (iii) seek to provide sufficient liquidity to pay current benefits and expenses; (iv) attempt to limit risk exposure through prudent diversification; and (v) seek to limit costs of administering and managing the plans. The Committee recognizes that risk and volatility are present to some degree with all types of investments. High levels of risk may be avoided through diversification by asset class, style of each investment manager and sector and industry limits. Investment managers are retained to manage a pool of assets and allocate funds in order to achieve an appropriate, diversified and balanced asset mix. The Committee’s strategy balances the requirement to maximize returns using potentially higher-return generating assets, such as equity securities, with the need to control the risk of its benefit obligations with less volatile assets, such as fixed-income securities. The Committee approves the target asset allocations. Registrant’s pension and post-retirement plan weighted-average asset allocations at December 31, 2020 and 2019, by asset category are as follows: Pension Benefits Post-Retirement Asset Category 2020 2019 2020 2019 Actual Asset Allocations : Equity securities 59 % 56 % 63 % 61 % Debt securities 36 % 39 % 36 % 38 % Real Estate Funds 5 % 5 % — % — % Cash equivalents — % — % 1 % 1 % Total 100 % 100 % 100 % 100 % Equity securities did not include AWR’s Common Shares as of December 31, 2020 and 2019. Target Asset Allocations: Pension Benefits Post-retirement Equity securities 60 % 60 % Debt securities 40 % 40 % Total 100 % 100 % The Pension Plan assets are in collective trust funds managed by a management firm appointed by the Committee. The fair value of these collective trust funds is measured using net asset value per share. In accordance with ASU 2015-07 Disclosures for Investments in Certain Entities that Calculate Net Asset Value per Share (or Its Equivalents) , the fair value of the collective trust funds is not categorized in the fair value hierarchy as of December 31, 2020 and 2019. The following tables set forth the fair value, measured by net asset value, of the pension investment assets as of December 31, 2020 and 2019: Net Asset Value as of December 31, 2020 (dollars in thousands) Fair Value Unfunded Commitments Redemption Frequency Redemption Notice Period Cash equivalents $ 589 — N/A N/A Fixed income fund $ 76,221 — Daily Daily Equity securities : U.S. small/mid cap funds 21,837 — Daily Daily U.S. large cap funds 53,677 — Daily Daily International funds 50,488 — Daily Daily Total equity funds 126,002 — Real estate funds 10,335 — Daily Daily Total $ 213,147 — Net Asset Value as of December 31, 2019 (dollars in thousands) Fair Value Unfunded Commitments Redemption Frequency Redemption Notice Period Cash equivalents $ 600 — N/A N/A Fixed income fund 74,123 — Daily Daily Equity securities : U.S. small/mid cap funds 17,865 — Daily Daily U.S. large cap funds 47,132 — Daily Daily International funds 43,778 — Daily Daily Total equity funds 108,775 Real estate funds 8,979 — Daily Daily Total $ 192,477 — The collective trust funds may be invested or redeemed daily, and generally do not have any significant restrictions to redeem the investments. As previously discussed in Note 1, the accounting guidance for fair value measurements establishes a framework for measuring fair value and requires fair value measurements to be classified and disclosed in one of three levels. As required by the accounting guidance, assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. All equity investments in the post-retirement medical plan are Level 1 investments in mutual funds. The fixed income category includes corporate bonds and notes. The majority of fixed income investments range in maturities from less than 1 to 20 years. The fair values of these investments are based on quoted market prices in active markets. The following tables set forth by level, within the fair value hierarchy, the post-retirement plan's investment assets measured at fair value as of December 31, 2020 and 2019: Fair Value as of December 31, 2020 (dollars in thousands) Level 1 Level 2 Level 3 Total Fair Value of Post-Retirement Plan Assets: Cash equivalents $ 169 — — $ 169 Fixed income 4,436 — — 4,436 U.S. equity securities 7,707 — — 7,707 Total investments measured at fair value $ 12,312 — — $ 12,312 Fair Value as of December 31, 2019 (dollars in thousands) Level 1 Level 2 Level 3 Total Fair Value of Post-Retirement Plan Assets: Cash equivalents $ 69 — — $ 69 Fixed income 4,279 — — 4,279 U.S. equity securities 6,923 — — 6,923 Total investments measured at fair value $ 11,271 — — $ 11,271 Plan Contributions : During 2020, Registrant contributed $3.7 million to its pension plan and did not make a contribution to the post-retirement medical plan. Registrant expects to contribute approximately $3.6 million to its pension plan in 2021. Registrant’s policy is to fund the plans annually at a level which is deductible for income tax purposes and is consistent with amounts recovered in customer rates while also complying with ERISA's funding requirements. Benefit Payments : Estimated future benefit payments at December 31, 2020 for the next five years and thereafter are as follows (in thousands): Pension Benefits Post-Retirement Medical Benefits 2021 $ 8,572 $ 486 2022 9,262 503 2023 9,880 516 2024 10,494 489 2025 11,142 476 Thereafter 63,680 1,813 Total $ 113,030 $ 4,283 Assumptions : Certain actuarial assumptions, such as the discount rate, long-term rate of return on plan assets, mortality, and the healthcare cost trend rate have a significant effect on the amounts reported for net periodic benefit cost as well as the related benefit obligation amounts. Discount Rate — The assumed discount rate for pension and post-retirement medical plans reflects the market rates for high-quality corporate bonds currently available. Registrant’s discount rates were determined by considering the average of pension yield curves constructed of a large population of high quality corporate bonds. The resulting discount rate reflects the matching of plan liability cash flows to the yield curves. Expected Long-Term Rate of Return on Assets — The long-term rate of return on plan assets represents an estimate of long-term returns on an investment portfolio consisting of a mixture of equities, fixed income and other investments. To develop the expected long-term rate of return on assets assumption for the pension plan, Registrant considered the historical returns and the future expectations for returns for each asset class, as well as the target asset allocation of the pension portfolio. Registrant’s policy is to fund the medical benefit trusts based on actuarially determined amounts as allowed in rates approved by the CPUC. Registrant has invested the funds in the post-retirement trusts that will achieve a desired return and minimize amounts necessary to recover through rates. The mix is expected to provide for a return on assets similar to the Pension Plan and to achieve Registrant’s targeted allocation. This resulted in the selection of the 6.0% long-term rate of return on assets assumption for the union plan and 4.2% (net of income taxes) for the non-union plan portion of the post-retirement plan. Mortality — Mortality assumptions are a critical component of benefit obligation amounts and a key factor in determining the expected length of time for annuity payments. Registrant uses the latest mortality tables published by the Society of Actuaries. Accordingly, the benefit obligation amounts as of December 31, 2020 and 2019 have incorporated recent updates to the mortality tables. Healthcare Cost Trend Rate — The assumed health care cost trend rate for 2021 starts at 5.2% grading down to 4.4% in 2036 for those under age 65, and at 4.3% grading down to 4.0% in 2025 for those 65 and over. Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plans. Supplemental Executive Retirement Plan : Registrant has a supplemental executive retirement plan (“SERP”) that is intended to restore retirement benefits to certain key employees and officers of Registrant that are limited by Sections 415 and 401(a)(17) of the Internal Revenue Code of 1986, as amended. The Board of Directors approved the establishment of a Rabbi Trust created for the SERP. Assets in a Rabbi Trust can be subject to the claims of creditors; therefore, they are not considered as an asset for purposes of computing the SERP’s funded status. As of December 31, 2020, the balance in the Rabbi Trust totaled $25.9 million and is included in Registrant’s other property and investments. All equity investments in the Rabbi Trust are Level 1 investments in mutual funds. The fixed income category includes corporate bonds and notes. The fair values of these investments are based on quoted market prices in active markets. The following tables set forth by level, within the fair value hierarchy, the Rabbi Trust investment assets measured at fair value as of December 31, 2020 and 2019: Fair Value as of December 31, 2020 (dollars in thousands) Level 1 Level 2 Level 3 Total Fair Value of Assets held in Rabbi Trust: Cash equivalents $ 8 — — $ 8 Fixed income securities 10,201 — — 10,201 Equity securities 15,703 — — 15,703 Total investments measured at fair value $ 25,912 — — $ 25,912 Fair Value as of December 31, 2019 (dollars in thousands) Level 1 Level 2 Level 3 Total Fair Value of Assets held in Rabbi Trust: Cash equivalents $ 72 — — $ 72 Fixed income securities 8,427 — — 8,427 Equity securities 13,054 — — 13,054 Total investments measured at fair value $ 21,553 — — $ 21,553 The following provides a reconciliation of benefit obligations, funded status of the SERP, as well as a summary of significant estimates at December 31, 2020 and 2019: (dollars in thousands) 2020 2019 Change in Benefit Obligation: Benefit obligation at beginning of year $ 29,703 $ 24,517 Service cost 1,029 1,193 Interest cost 988 1,069 Actuarial (gain) loss 5,479 3,419 Benefits paid (597) (495) Benefit obligation at end of year $ 36,602 $ 29,703 Changes in Plan Assets: Fair value of plan assets at beginning and end of year — — Funded Status: Net amount recognized as accrued cost $ (36,602) $ (29,703) (in thousands) 2020 2019 Amounts recognized on the balance sheets: Current liabilities $ (602) $ (609) Non-current liabilities (36,000) (29,094) Net amount recognized $ (36,602) $ (29,703) Amounts recognized in regulatory assets consist of: Prior service cost $ — $ — Net loss 12,988 8,352 Regulatory assets 12,988 8,352 Unfunded accrued cost 23,614 21,351 Net liability recognized $ 36,602 $ 29,703 Changes in plan assets and benefit obligations recognized in regulatory assets consist of: Regulatory asset at beginning of year $ 8,352 $ 5,403 Net (gain) loss 5,479 3,419 Amortization of prior service credit — — Amortization of net loss (843) (470) Total change in regulatory asset 4,636 2,949 Regulatory asset at end of year $ 12,988 $ 8,352 Net periodic pension cost $ 2,860 $ 2,733 Change in regulatory asset 4,636 2,949 Total recognized in net periodic pension and regulatory asset $ 7,496 $ 5,682 Additional year-end information for plans with an accumulated benefit obligation in excess of plan assets: Projected benefit obligation $ 36,602 $ 29,703 Accumulated benefit obligation 30,428 26,251 Fair value of plan assets — — Weighted-average assumptions used to determine benefit obligations: Discount rate 2.52 % 3.36 % Rate of compensation increase 4.00 % 4.00 % The components of SERP expense, before allocation to the overhead pool, for 2020, 2019 and 2018 are as follows: (dollars in thousands, except percent) 2020 2019 2018 Components of Net Periodic Benefits Cost: Service cost $ 1,029 $ 1,193 $ 1,096 Interest cost 988 1,069 888 Amortization of prior service cost — — — Amortization of net loss 843 471 1,049 Net periodic pension cost $ 2,860 $ 2,733 $ 3,033 Weighted-average assumptions used to determine net periodic cost: Discount rate 3.36 % 4.40 % 3.72 % Rate of compensation increase 4.00 % 4.00 % 4.00 % Benefit Payments : Estimated future benefit payments for the SERP at December 31, 2020 for the next five years and thereafter are as follows (in thousands): 2021 $ 602 2022 792 2023 787 2024 1,039 2025 1,029 Thereafter 11,937 Total $ 16,186 401(k) Investment Incentive Program : Registrant has a 401(k) Investment Incentive Program under which employees may invest a percentage of their pay, up to a maximum investment prescribed by law, in an investment program managed by an outside investment manager. Registrant’s cash contributions to the 401(k) are based upon a percentage of individual employee contributions and for the years ended December 31, 2020, 2019 and 2018 were $2.7 million, $2.5 million and $2.4 million, respectively. The Investment Incentive Program also incorporates the defined contribution plan for employees hired on or after January 1, 2011. The cash contributions to the defined contribution plan for the years ended December 31, 2020, 2019 and 2018 were $1.9 million, $1.6 million and $1.3 million, respectively.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation Plans	Stock-Based Compensation Plans Summary Description of Stock Incentive Plans As of December 31, 2020, AWR had three active stock incentive plans: the 2016 stock incentive plan for its employees, and the 2003 and 2013 non-employee directors plans for its Board of Directors, each more fully described below. 2016 Employee Plans — AWR adopted this employee plan, following shareholder approval, to provide stock-based incentive awards in the form of restricted stock units, stock options and restricted stock to employees as a means of promoting the success of Registrant by attracting, retaining and more fully aligning the interests of employees with those of customers and shareholders. The 2016 employee plan also provides for the grant of performance awards. There are no stock options or restricted stock grants currently outstanding. For restricted stock unit awards, the Compensation Committee determines the specific terms, conditions and provisions relating to each restricted stock unit. Each employee who has been granted a time-vested restricted stock unit is entitled to dividend equivalent rights in the form of additional restricted stock units until vesting of the time-vested restricted stock units. In general, time-vested restricted stock units vest over a period of three years. Restricted stock units may also vest upon retirement if the grantee is at least 55 and the sum of the grantee's age and years of service are equal to or greater than 75, or upon death or total disability. In addition, restricted stock units may vest following a change in control if the Company terminates the grantee other than for cause or the employee terminates employment for good reason. Each restricted stock unit is non-voting and entitles the holder of the restricted stock unit to receive one Common Share. The Compensation Committee also has the authority to determine the number, amount or value of performance awards, the duration of the performance period or performance periods applicable to the award and the performance criteria applicable to each performance award for each performance period. Each outstanding performance award granted by the Compensation Committee has been in the form of restricted stock units that generally vest over a period of three years as provided in the performance award agreement. The amount of the performance award paid to an employee depends upon satisfaction of performance criteria following the end of a three-year performance period. Performance awards may also vest and be payable upon retirement if the grantee is at least 55 and the sum of the grantee's age and years of service are equal to or greater than 75, or upon death or total disability. In addition, performance awards may vest following a change in control if the Company terminates the grantee other than for cause or the employee terminates employment for good reason. The amount of the payment for performance awards granted will be at target in the event of death or a termination of employment (other than for cause) by the Company or termination by the employee for good reason within 24 months after a change in control. In all other circumstances, adjustments will be made to the amount of the payment to take into account the shortened performance period 2003 and 2013 Directors Plans — The Board of Directors and shareholders of AWR have approved the 2003 and 2013 directors plans in order to provide the non-employee directors with supplemental stock-based compensation to encourage them to increase their stock ownership in AWR. New grants may not be made under the 2003 directors plan. Under the 2013 non-employee directors plan, non-employee directors are entitled to receive restricted stock units equal to two times the then current annual retainer for services as a director divided by the fair market value of AWR's Common Shares on the date preceding the annual meeting. Such units are convertible to AWR's Common Shares 90 days after the grant date. All non-employee directors of AWR who were directors of AWR at the 2003 annual meeting have also received restricted stock units, which will be distributed upon termination of the director's service as a director. All restricted stock units and performance awards have been granted with dividend equivalent rights payable in the form of additional restricted stock units. Recognition of Compensation Expense Registrant recognizes compensation expense related to the fair value of stock-based compensation awards. Share-based compensation cost is measured at the grant date, based on the calculated fair value of the award, and is recognized as an expense over the employee’s requisite service period (generally the vesting period of the equity grant). Immediate vesting occurs if the employee is at least 55 years old and the sum of the employee’s age and years of employment is equal to or greater than 75. Registrant assumes that pre-vesting forfeitures will be minimal, and recognizes pre-vesting forfeitures as they occur, which results in a reduction in compensation expense. The following table presents share-based compensation expenses for the years ended December 31, 2020, 2019 and 2018. These expenses resulting from restricted stock units, including performance awards, are included in administrative and general expenses in AWR's and GSWC’s statements of income: AWR GSWC For The Years Ended December 31, For The Years Ended December 31, (in thousands) 2020 2019 2018 2020 2019 2018 Stock-based compensation related to: Restricted stock units $ 2,463 $ 2,517 $ 3,851 $ 2,349 $ 2,253 $ 3,397 Total stock-based compensation expense $ 2,463 $ 2,517 $ 3,851 $ 2,349 $ 2,253 $ 3,397 Equity-based compensation cost capitalized as part of utility plant for the years ended December 31, 2020, 2019 and 2018 was $299,000, $265,000 and $199,000, respectively, for both AWR and GSWC. For the years ended December 31, 2020, 2019 and 2018, approximately $1.2 million, $1.8 million and $1.6 million, respectively, of tax benefits from stock-based awards were recorded for both AWR and GSWC. Registrant amortizes stock-based compensation over the requisite (vesting) period for the entire award. Time-vesting restricted stock units vest and become nonforfeitable in installments of 33% the first two years and 34% in the third year, starting one year from the date of the grant. Outstanding performance awards vest and become nonforfeitable in installments of 33% the first two years and 34% in the third year and are distributed at the end of the performance period if the performance criteria set forth in the award agreement are satisfied. Restricted Stock Units (Time-Vested) — A restricted stock unit (“RSU”) represents the right to receive a share of AWR’s Common Shares and are valued based on the fair market value of AWR's Common Shares on the date of grant. The fair value of RSUs were determined based on the closing trading price of Common Shares on the grant date. A summary of the status of Registrant’s outstanding RSUs, excluding performance awards, to employees and directors as of December 31, 2020, and changes during the year ended December 31, 2020, is presented below: Number of Weighted Average Restricted share units at January 1, 2020 75,071 $ 46.92 Granted 19,307 86.41 Vested (23,713) 58.56 Forfeited (1,326) 78.24 Restricted share units at December 31, 2020 69,339 $ 53.33 As of December 31, 2020, there was approximately $587,000 of total unrecognized compensation cost related to time-vested restricted stock units granted under AWR’s employee stock plans. That cost is expected to be recognized over a weighted average period of 1.21 years. Restricted Stock Units (Performance Awards) – During the years ended December 31, 2020, 2019 and 2018, the Compensation Committee granted performance awards in the form of restricted stock units to officers of the Registrant. A performance award represents the right to receive a share of AWR's Common Shares if specified performance goals are met over the performance period specified in the grant (generally three years). Each grantee of any outstanding performance award may earn between 0% and 200% of the target amount, which varies by target, depending on Registrant's performance against performance goals, which are determined by the Compensation Committee on the date of grant. As determined by the Compensation Committee, the performance awards granted during the years ended December 31, 2020, 2019 and 2018 included various performance-based conditions and one market-based condition related to total shareholder return ("TSR") that will be earned based on Registrant’s TSR compared to the TSR for a specific peer group of investor-owned water companies. A summary of the status of Registrant’s outstanding performance awards to officers as of December 31, 2020, and changes during the year ended December 31, 2020, is presented below: Number of Weighted Average Performance awards at January 1, 2020 84,649 $ 51.85 Granted 16,375 89.15 Performance criteria adjustment (670) 38.14 Vested (41,434) 44.80 Forfeited (960) 82.47 Performance awards at December 31, 2020 57,960 $ 66.40

Commitments

Commitments	12 Months Ended
	Dec. 31, 2020
Risks and Uncertainties [Abstract]
Commitments	Commitments GSWC’s Water Supply : GSWC has contracts to purchase water or water rights for an aggregate amount of $3.8 million as of December 31, 2020. Included in the $3.8 million is a commitment of $1.9 million to use water rights from a third party under an agreement, which expires in 2028. The remaining $1.9 million is for commitments for purchased water with other third parties, which expire from 2025 through 2038. GSWC’s estimated future minimum payments under these purchased water supply commitments at December 31, 2020 are as follows (in thousands): 2021 $ 426 2022 426 2023 426 2024 426 2025 383 Thereafter 1,675 Total $ 3,762 Bear Valley Electric Service, Inc. : Purchased Power Contracts: Generally, BVESI purchases power at a fixed cost, under long-term purchased power contracts, depending on the amount of power and the period during which the power is purchased under such contracts. BVESI began taking power pursuant to purchased power contracts approved by the CPUC effective in the fourth quarter of 2019 at a fixed cost over three Renewables Portfolio Standard: BVESI is subject to the renewables portfolio standard (“RPS”) law, which requires BVESI to meet certain targets for purchases of energy from qualified renewable energy resources. BVESI has an agreement with a third party to purchase renewable energy credits (“RECs”) whereby BVESI agreed to purchase approximately 578,000 RECs over a ten-year period through 2023, which will be used towards BVESI meeting California's RPS requirements. As of December 31, 2020, BVESI has purchased sufficient RECs to be in compliance for all periods through 2020. Accordingly, management does not believe any provision for loss or potential penalties is required as of December 31, 2020. The cost of these RECs has been included as part of the electric supply cost balancing account as of December 31, 2020. See Note 16 for Registrant’s future minimum payments under long-term non-cancelable operating leases.

Contingencies and Gain on Sale

Contingencies and Gain on Sale of Assets	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Environmental Clean-Up and Remediation : GSWC has been involved in environmental remediation and cleanup at one of its plant sites that contained an underground storage tank, which was used to store gasoline for its vehicles. This tank was removed from the ground in July 1990 along with the dispenser and ancillary piping. Since then, GSWC has been involved in various remediation activities at this site. Analysis indicates that offsite monitoring wells may also be necessary to document effectiveness of remediation. As of December 31, 2020, the total spent to clean-up and remediate the plant site was approximately $6.4 million, of which $1.5 million has been paid by the State of California Underground Storage Tank Fund. Amounts paid by GSWC have been included in rate base and approved by the CPUC for recovery. As of December 31, 2020, GSWC has a regulatory asset and an accrued liability for the estimated remaining cost of $1.3 million to complete the cleanup at the site. The estimate includes costs for 2 years of continued activities of groundwater cleanup and monitoring, future soil treatment and site-closure-related activities. The ultimate cost may vary as there are many unknowns in remediation of underground gasoline spills and this is an estimate based on currently available information. Management also believes it is probable that the estimated additional costs will continue to be approved in rate base by the CPUC. Condemnation of Properties : The laws of the State of California provide for the acquisition of public utility property by governmental agencies through their power of eminent domain, also known as condemnation, where doing so is necessary and in the public interest. In addition, these laws provide that the owner of utility property (i) may contest whether the condemnation is necessary and in the public interest, and (ii) is entitled to receive the fair market value of its property if the property is ultimately taken. Other Litigation : Registrant is also subject to other ordinary routine litigation incidental to its business, some of which may include claims for compensatory and punitive damages. Management believes that rate recovery, proper insurance coverage and reserves are in place to insure against, among other things, property, general liability, employment and workers’ compensation claims incurred in the ordinary course of business. Insurance coverage may not cover certain claims involving punitive damages. However, Registrant does not believe the outcome from any pending suits or administrative proceedings will have a material effect on Registrant's consolidated results of operations, financial position or cash flows.

Leases Leases

Leases Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Leases Right-of-use ("ROU") assets represent the right to use an underlying asset for the lease term, and lease liabilities represent the obligation to make lease payments arising from the lease. ROU assets and liabilities are recognized at the lease commencement date based on the estimated present value of lease payments over the lease term. As of December 31, 2020, Registrant has right-of-use assets of $11.1 million, short-term operating lease liabilities of $2.0 million and long-term operating lease liabilities of $9.6 million. Significant assumptions and judgments made as part of the adoption of this new lease standard include determining (i) whether a contract contains a lease, (ii) whether a contract involves an identified asset, and (iii) which party to the contract directs the use of the asset. The discount rates used to calculate the present value of lease payments were determined based on hypothetical borrowing rates available to Registrant over terms similar to the lease terms. Registrant’s leases consist of real estate and equipment leases, which are mostly GSWC's. Most of Registrant's leases require fixed lease payments. Some real estate leases have escalation payments which depend on an index. Variable lease costs were not material. Lease terms used to measure the lease liability include options to extend the lease if the option is reasonably certain to be exercised. Lease and non-lease components were combined to measure lease liabilities. Registrant's supplemental lease information for the year ended December 31, 2020 is as follows (in thousands, except for weighted average data): For The Year Ended December 31, 2020 For The Year Ended December 31, 2019 Operating lease costs $2,873 $3,166 Short-term lease costs 143 159 Weighted average remaining lease term (in years) 6.62 7.24 Weighted-average discount rate 3.6% 3.5% Non-cash transactions Lease liabilities arising from obtaining right-of-use assets $27 $18,034 For the years 2020, 2019 and 2018, Registrant’s consolidated rent expense was approximately $2.6 million, $2.8 million and $2.5 million, respectively. Registrant’s future minimum payments under long-term non-cancelable operating leases are as follows (in thousands): December 31, 2020 2021 $ 2,561 2022 2,318 2023 1,825 2024 1,503 2025 1,324 Thereafter 3,925 Total lease payments 13,456 Less: imputed interest 1,807 Total lease obligations 11,649 Less: current obligations 2,013 Long-term lease obligations $ 9,636 The consolidated operations of AWR and the operations of GSWC in regard to future minimum payments under long-term non-cancelable operating leases are not materially different.

Business Segments

Business Segments	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Business Segments	Business Segments AWR has 3 reportable segments, water, electric and contracted services. Since July 1, 2020, GSWC has 1 segment, water. Prior to July 1, 2020, GSWC also had an electric segment. On July 1, 2020, GSWC completed the transfer of the electric utility assets and liabilities from its electric division to BVESI, now a wholly owned direct subsidiary of AWR. As a result of this transfer, from July 1, 2020 onward, operating results and cash flows of the electric segment, as well as its assets and liabilities as of December 31, 2020, are no longer included in GSWC's financial statements, but continue to be included in AWR's consolidated financial statements (Note 20). On a stand-alone basis, AWR has no material assets other than its equity investments in its subsidiaries and note receivables therefrom, and deferred taxes. All activities of GSWC and BVESI are geographically located within California. Activities of ASUS and the Military Utility Privatization Subsidiaries are conducted in California, Florida, Georgia, Kansas, Maryland, New Mexico, North Carolina, South Carolina, Texas and Virginia. Each of the Military Utility Privatization Subsidiaries is regulated, if applicable, by the state in which the subsidiary primarily conducts water and/or wastewater operations. Fees charged for operations and maintenance and renewal and replacement services are based upon the terms of the contracts with the U.S. government which have been filed, as appropriate, with the commissions in the states in which ASUS’s subsidiaries are incorporated. The tables below set forth information relating to the water and electric operating segments, ASUS and the Military Utility Privatization Subsidiaries and other matters. The utility plant balances are net of respective accumulated provisions for depreciation. Capital additions reflect capital expenditures paid in cash and exclude U.S. government-funded and third-party prime funded capital expenditures for ASUS and property installed by developers and conveyed to GSWC and BVESI. As Of And For The Year Ended December 31, 2020 AWR Consolidated (dollars in thousands) Water Electric ASUS Parent AWR Operating revenues $ 330,637 $ 37,024 $ 120,582 $ — $ 488,243 Operating income (loss) 97,896 10,303 22,309 (9) 130,499 Interest expense, net 20,312 584 (496) 330 20,730 Utility Plant 1,400,489 89,308 22,246 — 1,512,043 Depreciation and amortization expense (1) 30,969 2,479 3,402 — 36,850 Income tax expense (benefit) 20,515 2,689 5,201 (208) 28,197 Capital additions 107,355 18,393 4,675 — 130,423 As Of And For The Year Ended December 31, 2019 GSWC AWR Consolidated (dollars in thousands) Water Electric ASUS Parent AWR Operating revenues $ 319,830 $ 39,548 $ 114,491 $ — $ 473,869 Operating income (loss) 93,895 11,197 21,990 (9) 127,073 Interest expense, net 20,304 1,228 (734) 539 21,337 Utility Plant 1,322,062 72,680 20,963 — 1,415,705 Depreciation and amortization expense (1) 29,956 2,485 2,956 — 35,397 Income tax expense/(benefit) 17,295 2,882 5,202 (709) 24,670 Capital additions 131,353 11,499 9,088 — 151,940 As Of And For The Year Ended December 31, 2018 GSWC AWR Consolidated (dollars in thousands) Water Electric ASUS Parent AWR Operating revenues $ 295,258 $ 34,350 $ 107,208 $ — $ 436,816 Operating income 74,342 6,220 20,414 7 100,983 Interest expense, net 18,403 1,328 (327) 451 19,855 Utility Plant 1,218,468 62,624 15,218 — 1,296,310 Depreciation and amortization expense (1) 36,137 2,258 2,030 — 40,425 Income tax expense/(benefit) 12,391 1,212 4,939 (525) 18,017 Capital additions 110,934 5,420 10,207 — 126,561 ____________________________ (1) Depreciation computed on regulated utilities' transportation equipment is recorded in other operating expenses and totaled $353,000, $316,000 and $238,000 for the years ended December 31, 2020, 2019 and 2018, respectively. The following table reconciles total utility plant (a key figure for rate-making) to total consolidated assets (in thousands): December 31, 2020 2019 Total utility plant $ 1,512,043 $ 1,415,705 Other assets 279,560 225,626 Total consolidated assets $ 1,791,603 $ 1,641,331

Allowance for Doubtful Accounts

Allowance for Doubtful Accounts	12 Months Ended
	Dec. 31, 2020
Allowance for Doubtful Accounts
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts Registrant adopted ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , effective January 1, 2020. The guidance requires estimated credit losses on financial instruments, such as Registrant's trade and other receivables, be based on expected credit losses rather than incurred losses. Registrant's allowance for doubtful accounts as of December 31, 2020 was developed based on the observed effects of the economic impact from the COVID-19 pandemic on GSWC's and BVESI's aging of utility customer accounts receivable, as well as economic data and other considerations that may impact customers' ability to pay their bills. Management also took into consideration the impact of the CPUC's order to suspend, through June 30, 2021, service disconnections for nonpayment, which is expected to have the effect of increasing delinquent customer accounts receivable during the COVID-19 pandemic. However, the CPUC has authorized GSWC and BVESI to track incremental costs, including bad debt expense in excess of what is included in their respective revenue requirements, incurred as a result of the pandemic in COVID-19 related memorandum accounts to be filed with the CPUC for future recovery. Other accounts receivable consist primarily of amounts due from third parties (non-utility customers) for various reasons, including amounts due from contractors, amounts due under settlement agreements, and amounts due from other third-party prime government contractors pursuant to agreements for construction of water and/or wastewater facilities for such third-party prime contractors. Thus far, the COVID-19 pandemic has not materially impacted the collectability of these other accounts receivable. The table below presents Registrant’s provision for doubtful accounts charged to expense and accounts written off, net of recoveries. Provisions included in 2020, 2019, and 2018 for AWR and GSWC are as follows: AWR December 31, (dollars in thousands) 2020 2019 2018 Balance at beginning of year $ 916 $ 951 $ 1,041 Provision charged to expense 5,016 609 841 Accounts written off, net of recoveries (616) (644) (931) Balance at end of year $ 5,316 $ 916 $ 951 Allowance for doubtful accounts related to accounts receivable-customer $ 5,263 $ 857 $ 892 Allowance for doubtful accounts related to other accounts receivable 53 59 59 Total allowance for doubtful accounts $ 5,316 $ 916 $ 951 GSWC December 31, (dollars in thousands) 2020 2019 2018 Balance at beginning of year $ 916 $ 951 $ 865 Provision charged to expense 4,703 607 850 Balance transfer to BVESI (Note 20) (79) — — Accounts written off, net of recoveries (580) (642) (764) Balance at end of year $ 4,960 $ 916 $ 951 Allowance for doubtful accounts related to accounts receivable-customer $ 4,907 $ 857 $ 892 Allowance for doubtful accounts related to other accounts receivable 53 59 59 Total allowance for doubtful accounts $ 4,960 $ 916 $ 951

Statement of Cash Flows, Supple

Statement of Cash Flows, Supplemental Disclosures	12 Months Ended
	Dec. 31, 2020
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information The following table sets forth non-cash financing and investing activities and other cash flow information (in thousands). AWR GSWC December 31, December 31, 2020 2019 2018 2020 2019 2018 Taxes and Interest Paid: Income taxes paid, net $ 13,684 $ 22,496 $ 21,084 $ 8,184 $ 17,206 $ 19,448 Interest paid, net of capitalized interest 19,941 25,080 23,471 19,681 23,925 22,721 Non-Cash Transactions: Accrued payables for investment in utility plant 27,861 23,736 27,403 25,633 23,736 27,403 Property installed by developers and conveyed 3,102 6,220 2,082 3,102 6,220 2,082 Transfer of electric segment net assets (net of cash) for BVESI common shares (Note 20) — — — 71,324 — — Distribution of BVESI common shares to AWR parent (Note 20) — — — 71,344 — —

Completion of Electric Utility

Completion of Electric Utility Reorganization Plan	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
Completion of Electric Utility Reorganization Plan	Completion of Electric Utility Reorganization Plan On July 1, 2020, GSWC completed the transfer of approximately $71.3 million in net assets and equity (based on their recorded amounts) from its electric utility division to BVESI in exchange for common shares of BVESI of equal value. This was a non-cash transaction, and no gain or loss was recognized. GSWC then immediately distributed all of BVESI's common shares to AWR, whereupon BVESI became wholly owned directly by AWR. The reorganization did not result in any substantive changes to AWR's operations or business segments. In addition, pursuant to federal and state tax law, the exchange and distribution qualify as a tax-free reorganization; consequently, no income tax liability was triggered for the AWR consolidated group or any of its members. The transfer between GSWC and BVESI, both wholly owned subsidiaries of AWR, is considered a common control transaction. Although the electric utility division was considered a separate business segment and component of GSWC, the transfer did not qualify as a discontinued operation based on management's assessment of the applicable accounting guidance. As a result of this transfer, from July 1, 2020 onward, operating results and cash flows of the electric segment, as well as its assets and liabilities as of December 31, 2020, are no longer included in GSWC's financial statements, but continue to be included in AWR's consolidated financial statements. GSWC's statement of income for 2020 includes the electric segment's results through June 30, 2020. The table below sets forth selected information relating to the electric segment's results of operations for the six months ended December 31, 2020 and 2019, and its cash flows for the six months ended December 31, 2020 (in thousands): Six Months Ended December 31, 2020 2019 (1) (Subsidiary of AWR) (Division of GSWC) Electric revenues $ 18,377 $ 21,510 Operating expenses 13,074 13,153 Operating income 5,303 8,357 Net income $ 3,870 $ 5,422 Six Months Ended December 31, 2020 (Subsidiary of AWR) Net cash provided from operating activities $ 1,887 Net cash used in investing activities (capital expenditures) (9,339) Net cash provided from financing activities (2) 7,799 Net change in cash and cash equivalents 347 Cash and cash equivalents, beginning of period 20 Cash and cash equivalents, end of period $ 367 (1) Operating income for the six months ended December 31, 2019 included the retroactive impact of the CPUC's August 2019 final decision on the electric general rate case, which totaled approximately $3.7 million for periods prior to July 1, 2019. (2) Effective July 1, 2020, BVESI entered into a 3-year, $35.0 million revolving credit facility agreement with a bank and began borrowing under this facility. As of December 31, 2020, there was $20.2 million outstanding under this new facility. Under the terms of the credit agreement, BVESI has the option to request an increase in the facility by an additional $15.0 million. Offsetting the increase from borrowings under this credit facility was dividends in the amount of $12.4 million that were paid to AWR by BVESI during the fourth quarter of 2020.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited) (Notes)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Data [Abstract]
Quarterly Financial Information	Note 21 — Selected Quarterly Financial Data (Unaudited) The quarterly financial information presented below is unaudited. Registrant's business is seasonal, and it is management’s opinion that comparisons of earnings for the quarterly periods do not reflect overall trends and changes in Registrant’s operations. AWR For The Year Ended December 31, 2020 (in thousands, except per share amounts) First Second Third Fourth Year Operating revenues $ 109,077 $ 121,278 $ 133,688 $ 124,200 $ 488,243 Operating income 25,699 35,716 39,807 29,277 130,499 Net income 14,072 25,612 26,530 20,211 86,425 Basic earnings per share 0.38 0.69 0.72 0.55 2.34 Diluted earnings per share 0.38 0.69 0.72 0.54 2.33 GSWC For The Year Ended December 31, 2020 (in thousands) First Second Third Fourth Year (1) Operating revenues $ 82,392 $ 94,753 $ 98,701 $ 73,438 $ 349,284 Operating income 22,092 30,175 33,149 17,480 102,896 Net income 11,202 20,919 21,143 11,707 64,971 AWR For The Year Ended December 31, 2019 (in thousands, except per share amounts) First Second Third Fourth Year Operating revenues $ 101,733 $ 124,647 $ 134,496 $ 112,993 $ 473,869 Operating income 20,195 39,430 42,724 24,724 127,073 Net income 12,852 26,784 28,006 16,700 84,342 Basic earnings per share 0.35 0.72 0.76 0.45 2.28 Diluted earnings per share 0.35 0.72 0.76 0.45 2.28 GSWC For The Year Ended December 31, 2019 (in thousands) First Second Third Fourth Year Operating revenues $ 75,352 $ 95,548 $ 107,245 $ 81,233 $ 359,378 Operating income 15,327 34,037 36,982 18,746 105,092 Net income 9,022 22,298 23,362 11,981 66,663 (1) As a result of GSWC's transfer of electric net assets to BVESI, from July 1, 2020 onward, operating results of the electric segment are no longer included in GSWC's financial statements, but continue to be included in AWR's consolidated financial statements. GSWC's operating revenues, operating income and net income for 2020 includes the electric segment's results through June 30, 2020. (2) The second quarter of 2019 includes approximately $4.0 million of operating income related to the first quarter of 2019 as a result of the final CPUC decision on the water general rate case, which was received in May 2019 and was retroactive to January 1, 2019. (3) The third quarter of 2019 includes the retroactive impact of the final decision on the electric general rate case approved by the CPUC in August 2019, which was retroactive to January 1, 2018. Included in the third quarter of 2019 results are approximately $1.4 million of pretax income related to the first two quarters of 2019 and approximately $2.3 million of pretax income related to 2018.

SCHEDULE I - CONDENSED FINANCIA

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT	CONDENSED BALANCE SHEETS December 31, (in thousands) 2020 2019 Assets Cash and equivalents $ 441 $ 310 Income taxes receivable 72 — Intercompany note receivables 32,819 185,094 Total current assets 33,332 185,404 Investments in subsidiaries 716,627 616,725 Deferred taxes and other assets 9,757 9,548 Total assets $ 759,716 $ 811,677 Liabilities and Capitalization Notes payable to bank $ — $ 5,000 Income taxes payable 2,123 3,259 Other liabilities 272 274 Total current liabilities 2,395 8,533 Notes payable to bank 114,000 200,000 Deferred taxes and other liabilities 1,648 1,614 Total other liabilities 115,648 201,614 Common shareholders’ equity 641,673 601,530 Total capitalization 641,673 601,530 Total liabilities and capitalization $ 759,716 $ 811,677 The accompanying condensed notes are an integral part of these condensed financial statements. CONDENSED STATEMENTS OF INCOME For the Years Ended December 31, (In thousands, except per share amounts) 2020 2019 2018 Operating revenues and other income $ — $ — $ — Operating expenses and other expenses 90 314 305 Income before equity in earnings of subsidiaries and income taxes (90) (314) (305) Equity in earnings of subsidiaries 86,307 83,947 63,651 Income before income taxes 86,217 83,633 63,346 Income tax benefit (208) (709) (525) Net income $ 86,425 $ 84,342 $ 63,871 Weighted Average Number of Common Shares Outstanding 36,880 36,814 36,733 Basic Earnings Per Common Share $ 2.34 $ 2.28 $ 1.73 Weighted Average Number of Diluted Common Shares Outstanding 36,995 36,964 36,936 Fully Diluted Earnings per Common Share $ 2.33 $ 2.28 $ 1.72 Dividends Paid Per Common Share 1.280 $ 1.160 $ 1.060 The accompanying condensed notes are an integral part of these condensed financial statements. CONDENSED STATEMENTS OF CASH FLOWS For the Years Ended December 31, (in thousands) 2020 2019 2018 Cash Flows From Operating Activities $ 47,307 $ 40,459 $ 79,877 Cash Flows From Investing Activities: Loans (made to)/repaid from, wholly-owned subsidiaries 151,000 (107,500) (30,500) Increase in investment of subsidiary (60,000) — (47,500) Net cash provided (used) in investing activities 91,000 (107,500) (78,000) Cash Flows From Financing Activities: Proceeds from stock option exercises 30 519 546 Net change in notes payable to banks (91,000) 109,500 36,500 Proceeds from note payable to GSWC (6,000) — — Repayment of note payable to GSWC 6,000 — — Dividends paid (47,206) (42,702) (38,937) Net cash (used) provided in financing activities (138,176) 67,317 (1,891) Change in cash and equivalents 131 276 (14) Cash and equivalents at beginning of period 310 34 48 Cash and equivalents at the end of period $ 441 $ 310 $ 34 The accompanying condensed financial statements of AWR (parent) should be read in conjunction with the consolidated financial statements and notes thereto of American States Water Company and subsidiaries (“Registrant”) included in Part II, Item 8 of this Form 10-K. AWR’s (parent) significant accounting policies are consistent with those of Registrant and its wholly owned subsidiaries, Golden State Water Company (“GSWC”), Bear Valley Electric Service, Inc. ("BVESI") and American States Utility Services, Inc. ("ASUS"), except that all subsidiaries are accounted for as equity method investments. Related-Party Transactions: As further discussed in Note 2 — Notes Payable to Banks , AWR (parent) currently has access to a $200.0 million revolving credit facility. AWR (parent) borrows under this facility and provides funds to GSWC and ASUS in support of their operations. Any amounts owed to AWR (parent) for borrowings under this facility are reflected as inter-company receivables on the condensed balance sheets. The interest rate charged to the subsidiaries is sufficient to cover AWR (parent)’s interest cost under the credit facility. In October 2020, AWR (parent) issued an interest bearing promissory note to GSWC, which expires in May 2023. Under the terms of the note, AWR (parent) may borrow from GSWC amounts up to $30 million for working capital purposes. AWR (parent) agrees to pay any unpaid principal amounts outstanding under this note, plus accrued interest. In November 2020, AWR (parent) borrowed $6 million from GSWC under the terms of the note, which was subsequently repaid in December. As of December 31, 2020, there were no amounts outstanding under this note. AWR (parent) guarantees performance of ASUS's military privatization contracts and agrees to provide necessary resources, including financing, which are necessary to assure the complete and satisfactory performance of such contracts. AWR currently has access to a $200.0 million credit facility expiring in May 2023 in order to provide funds to GSWC and ASUS in support of their operations on terms that are similar to that of the credit facility. During 2019 and 2020, AWR amended the credit facility to temporarily increase the borrowing capacity as high as $260.0 million in order to meet the operational needs of GSWC and ASUS. Following the issuance of GSWC’s long-term debt in July 2020, AWR reduced the aggregate borrowing capacity to $200.0 million pursuant to the terms of that credit facility agreement. At December 31, 2020, there was $134.2 million outstanding under the credit facility. The aggregate effective amount that may be outstanding under letters of credit is $25.0 million. AWR has obtained letters of credit, primarily for GSWC, in the aggregate amount of $455,000 at fees of 0.65%. Letters of credit outstanding reduce the amount that may be borrowed under the revolving credit facility. AWR is not required to maintain any compensating balances. Loans may be obtained under this credit facility at the option of AWR and bear interest at rates based on credit ratings and Euro rate margins. In June 2020, Standard and Poor’s Global Ratings (“S&P”) affirmed an A+ credit rating with a stable outlook on both AWR and GSWC. S&P’s debt ratings range from AAA (highest possible) to D (obligation is in default). AWR’s (parent) borrowing activities (excluding letters of credit) for the years ended December 31, 2020 and 2019 were as follows: December 31, (in thousands, except percent) 2020 2019 Balance Outstanding at December 31, $ 114,000 $ 205,000 Interest Rate at December 31, 1.19 % 2.44 % Average Amount Outstanding 160,495 $ 167,392 Weighted Average Annual Interest Rate 1.47 % 2.88 % Maximum Amount Outstanding $ 249,000 $ 205,500 All of the letters of credit are issued pursuant to the revolving credit facility. The revolving credit facility contains restrictions on prepayments, disposition of property, mergers, liens and negative pledges, indebtedness and guaranty obligations, transactions with affiliates, minimum interest coverage requirements, a maximum debt to capitalization ratio and a minimum debt rating. Pursuant to the credit agreement, AWR must maintain a minimum interest coverage ratio of 3.25 times interest expense, a maximum total funded debt ratio of 0.65 to 1.00 and a minimum debt rating from Moody’s or S&P of Baa3 or BBB-, respectively. As of December 31, 2020, 2019 and 2018, AWR was in compliance with these covenants. As of December 31, 2020, AWR had an interest coverage ratio of 7.74 times interest expense, a debt ratio of 0.47 to 1.00 and a debt rating of A+ by S&P.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Nature of Operations : American States Water Company (“AWR”) is the parent company of Golden State Water Company (“GSWC”), Bear Valley Electric Service Inc. ("BVESI"), and American States Utility Services, Inc. (“ASUS”) (and its wholly owned subsidiaries, Fort Bliss Water Services Company (“FBWS”), Terrapin Utility Services, Inc. (“TUS”), Old Dominion Utility Services, Inc. (“ODUS”), Palmetto State Utility Services, Inc. (“PSUS”), Old North Utility Services, Inc. (“ONUS”), Emerald Coast Utility Services, Inc. (“ECUS”), and Fort Riley Utility Services, Inc. ("FRUS")). AWR and its subsidiaries may be collectively referred to as “Registrant” or “the Company.” The subsidiaries of ASUS are collectively referred to as the “Military Utility Privatization Subsidiaries.” On July 1, 2020, GSWC completed the transfer of the electric utility assets and liabilities from its electric division to BVESI, a separate legal entity and wholly owned subsidiary of AWR (Note 20). This reorganization did not result in any substantive changes to AWR's operations and business segments. AWR, through its wholly owned subsidiaries, serves over one million people in nine states. GSWC and BVESI are both California public utilities, with GSWC engaged in the purchase, production, distribution and sale of water throughout California serving approximately 261,800 customers, while BVESI distributes electricity in several San Bernardino County mountain communities in California serving approximately 24,500 customers. The California Public Utilities Commission (“CPUC”) regulates GSWC’s and BVESI's businesses in matters including properties, rates, services, facilities, and transactions between GSWC, BVESI, and their affiliates. ASUS, through its Military Utility Privatization Subsidiaries, operates, maintains and performs construction activities (including renewal and replacement capital work) on water and/or wastewater systems at various U.S. military bases pursuant to 50-year firm fixed-price contracts. These contracts are subject to annual economic price adjustments and modifications for changes in circumstances, changes in laws and regulations and additions to the contract value for new construction of facilities at the military bases. There is no direct regulatory oversight by the CPUC over AWR or the operations, rates or services provided by ASUS or the Military Utility Privatization Subsidiaries. Basis of Presentation : The consolidated financial statements and notes thereto are presented in a combined report filed by two separate Registrants: AWR and GSWC. References in this report to “Registrant” are to AWR and GSWC, collectively, unless otherwise specified. AWR owns all of the outstanding Common Shares of GSWC, BVESI and ASUS. ASUS owns all of the outstanding common shares of the Military Utility Privatization Subsidiaries. The consolidated financial statements of AWR include the accounts of AWR and its subsidiaries. These financial statements are prepared in conformity with accounting principles generally accepted in the United States of America. Intercompany transactions and balances have been eliminated in the AWR consolidated financial statements.
Related Party Transactions [Policy Text Block]	Related-Party Transactions : GSWC, BVESI and ASUS provide and/or receive various support services to and from their parent, AWR, and among themselves. GSWC also allocates certain corporate office administrative and general costs to its affiliates using allocation factors approved by the CPUC. During the years ended December 31, 2020, 2019 and 2018, GSWC allocated to ASUS approximately $4.9 million, $4.7 million and $4.2 million, respectively, of corporate office administrative and general costs. During the year ended December 31, 2020, GSWC allocated corporate office administrative and general costs to BVESI of approximately $1.3 million. Furthermore, AWR borrows under a credit facility, which expires in May 2023, and provides funds to GSWC and ASUS in support of their operations. The interest rate charged to GSWC and ASUS is sufficient to cover AWR’s interest expense under the credit facility. The CPUC requires GSWC to pay down all intercompany borrowings from AWR within a 24-month period, which was required by November 2020. In October 2020, the Board of Directors authorized AWR to invest equity in GSWC to enable the subsidiary to pay down all its intercompany borrowings. During the fourth quarter of 2020, AWR invested $60 million of equity in GSWC and received five shares of GSWC common stock. The majority of the proceeds from this stock issuance were used by GSWC to pay down its intercompany borrowings from AWR, satisfying the CPUC’s requirement. As a result, GSWC had no intercompany borrowings from AWR as of December 31, 2020. In October 2020, AWR issued an interest bearing promissory note to GSWC, which expires in May 2023. Under the terms of the note, AWR may borrow from GSWC amounts up to $30 million for working capital purposes. AWR agrees to pay any unpaid principal amounts outstanding under this note, plus accrued interest. In November 2020, AWR borrowed $6 million from GSWC under the terms of the note, which was subsequently repaid in December. As of December 31, 2020, there were no amounts outstanding under this note.
COVID-19 Impact [Policy Text Block]	COVID-19 Impact : GSWC, BVESI, and ASUS have continued their operations given that their water, wastewater, and electric utility services are deemed essential. AWR's responses take into account orders issued by the CPUC, and the guidance provided by federal, state, and local health authorities and other government officials to the COVID-19 pandemic. Some of the actions taken by GSWC and BVESI include: (i) suspending service disconnections for nonpayment pursuant to CPUC orders; (ii) increasing the number of employees telecommuting; and (iii) delaying some capital improvement projects at GSWC. In February 2021, the CPUC adopted a resolution that extended the existing emergency customer protections previously established by the CPUC through June 30, 2021, including the suspension of service disconnections for non-payment, in response to the on-going COVID-19 pandemic. Among other things, the resolution also extends the COVID-19-related memorandum accounts established to track incremental costs associated with complying with the resolution, and requires utilities in California to file transition plans to address the eventual discontinuance of the emergency customer protections. The goal of the transition plan is to effectively ease customers through a transition off the emergency customer protections by proactively communicating with customers to enroll them in programs to manage their utility bills and informing them of the changes to programs in which they are already enrolled. GSWC and BVESI are in the process of developing their transition plans, which are required to be finalized and filed with the CPUC by April 1, 2021. The pandemic has caused significant volatility on financial markets, resulting in significant fluctuations in the fair value of plan assets in GSWC's pension and other retirement plans, which could continue. In addition, due to expected future credit losses on utility customer bills, GSWC and BVESI have increased their allowance for doubtful accounts as of December 31, 2020. However, the CPUC has authorized GSWC and BVESI to track incremental costs, including bad debt expense in excess of what is included in their respective revenue requirements, incurred as a result of the pandemic in COVID-19-related memorandum accounts, such as a Catastrophic Event Memorandum Account ("CEMA"), to be filed with the CPUC for future recovery. GSWC and BVESI have recorded approximately $4.4 million in these accounts as regulatory assets, as it is believed such amounts are probable of recovery. CEMA and other emergency-type memorandum accounts are established as a result of a state/federal declared emergency, and are therefore recognized as regulatory assets for future recovery. As a result, the amounts recorded in the COVID-19-related memorandum accounts have not impacted GSWC's and BVESI's earnings in 2020. Thus far, the COVID-19 pandemic has not had a material impact on ASUS's operations.
Utility Accounting [Policy Text Block]	Utility Accounting : Registrant’s accounting policies conform to accounting principles generally accepted in the United States of America ("GAAP"), including the accounting principles for rate-regulated enterprises, which reflect the ratemaking policies of the CPUC and, to the extent applicable, the Federal Energy Regulatory Commission. GSWC and BVESI have incurred various costs and received various credits reflected as regulatory assets and liabilities. Accounting for such costs and credits as regulatory assets and liabilities is in accordance with the guidance for accounting for the effects of certain types of regulation. This guidance sets forth the application of GAAP for those companies whose rates are established by or are subject to approval by an independent third-party regulator. Under such accounting guidance, rate-regulated entities defer costs and credits on the balance sheet as regulatory assets and liabilities when it is probable that those costs and credits will be recognized in the ratemaking process in a period different from the period in which they would have been reflected in income by an unregulated company. These regulatory assets and liabilities are then recognized in the income statement in the period in which the same amounts are reflected in the rates charged for service. The amounts included as regulatory assets and liabilities that will be collected or refunded over a period exceeding one year are classified as long-term assets and liabilities as of December 31, 2020 and 2019.
Property and Depreciation [Policy Text Block]	Property and Depreciation : Registrant's property consists primarily of regulated utility plant at GSWC and BVESI. GSWC and BVESI capitalize, as utility plant, the cost of construction and the cost of additions, betterments and replacements of retired units of property. Such cost includes labor, material and certain indirect charges. Water systems acquired are recorded at estimated original cost of utility plant when first devoted to utility service and the applicable depreciation is recorded to accumulated depreciation. The difference between the estimated original cost, less accumulated depreciation, and the purchase price, if recognized by the CPUC, is recorded as an acquisition adjustment within utility plant. Depreciation is computed on the straight-line, remaining-life basis, group method, in accordance with the applicable ratemaking process. The provision for depreciation expressed as a percentage of the aggregate depreciable asset balances for regulated utilities was 2.2% for 2020, 2.2% for 2019, and 2.7% for 2018. Depreciation expense for regulated utilities, excluding amortization expense and depreciation on transportation equipment, totaled $32.9 million, $31.7 million and $37.3 million for the years ended December 31, 2020, 2019 and 2018, respectively. Depreciation computed on regulated utilities’ transportation equipment is recorded in other operating expenses and totaled $353,000, $316,000 and $238,000 for the years ended December 31, 2020, 2019 and 2018, respectively. Expenditures for maintenance and repairs are expensed as incurred. Retired property costs, including costs of removal, are charged to the accumulated provision for depreciation. Estimated useful lives of regulated utilities’ utility plant, as authorized by the CPUC, are as follows: Source of water supply 30 years to 50 years Pumping 25 years to 40 years Water treatment 20 years to 35 years Transmission and distribution 25 years to 55 years Generation 40 years Other plant 7 years to 40 years Non-regulated property consists primarily of equipment utilized by ASUS and its subsidiaries for its operations. This property is stated at cost, net of accumulated depreciation, which is calculated using the straight-line method over the useful lives of the assets.
Asset Retirement Obligation [Policy Text Block]	Asset Retirement Obligations : GSWC has a legal obligation for the retirement of its wells, which by law need to be properly capped at the time of removal. As such, GSWC incurs asset retirement obligations. GSWC records the fair value of a liability for these asset retirement obligations in the period in which they are incurred. When the liability is initially recorded, GSWC capitalizes the cost by increasing the carrying amount of the related long-lived asset. Over time, the liability is accreted to its present value each period, and the capitalized cost is depreciated over the useful life of the related asset. Upon settlement of the liability, GSWC either settles the obligation for its recorded amount or incurs a gain or loss upon settlement. Retirement costs have historically been recovered through rates subsequent to the retirement costs being incurred. Accordingly, recoverability of GSWC’s asset retirement obligations are reflected as a regulatory asset. GSWC also reflects the loss or gain at settlement as a regulatory asset or liability on the balance sheet. With regards to removal costs associated with certain other long-lived assets, such as water mains, distribution and transmission assets, asset retirement obligations have not been recognized as GSWC believes there is no legal obligation to do so. There are no CPUC rules or regulations that require GSWC to remove any of its other long-lived assets. In addition, GSWC’s water pipelines are not subject to regulation by any federal regulatory agency. GSWC has franchise agreements with various municipalities in order to use the public right of way for utility purposes (i.e., operate water distribution and transmission assets), and if certain events occur in the future, GSWC could be required to remove or relocate certain of its pipelines. However, it is not possible to estimate an asset retirement amount since the timing and the amount of assets that may be required to be removed, if any, is not known.
Impairment of Long-Lived Assets [Policy Text Block]	Impairment of Long-Lived Assets : Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be fully recoverable in accordance with accounting guidance for impairment or disposal of long-lived assets. Registrant would recognize an impairment loss on its regulated assets only if the carrying value amount of a long-lived asset is not recoverable from customer rates authorized by the CPUC. Impairment loss is measured as the excess of the carrying value over the amounts recovered in customer rates. For the years ended December 31, 2020, 2019 and 2018, no impairment loss was incurred.
Goodwill [Policy Text Block]	Goodwill : At December 31, 2020 and 2019, AWR had approximately $1.1 million of goodwill. The $1.1 million goodwill arose from ASUS’s acquisition of a subcontractor’s business at some of the Military Utility Privatization Subsidiaries. In accordance with the accounting guidance for testing goodwill, AWR annually assesses qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. For 2020, AWR’s assessment of qualitative factors did not indicate that an impairment had occurred for goodwill at ASUS.
Cash and Cash Equivalents [Policy Text Block]	Cash and Cash Equivalents: Cash and cash equivalents include short-term cash investments with an original maturity of three months or less. At times, cash and cash equivalent balances may be in excess of federally insured limits. Cash and cash equivalents are held with financial institutions with high credit standings.
Accounts Receivable [Policy Text Block]	Accounts Receivable : Accounts receivable is reported on the balance sheet net of any allowance for doubtful accounts. The allowance for doubtful accounts is Registrant’s best estimate of the amount of probable credit losses in Registrant’s existing accounts receivable from its water and electric customers, and is determined based on expected losses rather than incurred losses. Registrant reviews the allowance for doubtful accounts quarterly. Account balances are written off against the allowance when it is probable the receivable will not be recovered. When utility customers request extended payment terms, credit is extended based on regulatory guidelines, and collateral is not required. Receivables from the U.S. government include amounts due under contracts with the U.S. government to operate and maintain, and/or provide construction services for the water and/or wastewater systems at military bases. Other accounts receivable consist primarily of amounts due from third parties (non-utility customers) for various reasons, including amounts due from contractors, amounts due under settlement agreements and amounts due from other third-party prime government contractors pursuant to agreements for construction of water and/or wastewater facilities for such third-party prime contractors. The allowance for these other accounts receivable is based on Registrant’s evaluation of the receivable portfolio under current conditions and a review of specific problems and such other factors that, in Registrant’s judgment, should be considered in estimating losses. Allowances for doubtful accounts are disclosed in Note 18. Registrant adopted Accounting Standards Update 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments effective January 1, 2020.
Materials and Supplies [Policy Text Block]	Materials and Supplies: Materials and supplies are stated at the lower of cost or net realizable value. Cost is computed using weighted average cost. Major classes of materials include pipe, hydrants and valves.
Interest [Policy Text Block]	Interest : Interest incurred during the construction of capital assets has generally not been capitalized for financial reporting purposes as such policy is not followed in the ratemaking process. Interest expense is generally recovered through the regulatory process. However, the CPUC has authorized certain capital projects to be filed for revenue recovery with advice letters when those projects are completed. During the time that such projects are under development and construction, GSWC and BVESI may accrue an allowance for funds used during construction (“AFUDC”) on the incurred expenditures to offset the cost of financing project construction. For the year ended December 31, 2020, BVESI recorded $200,000 in AFUDC. For the years ended December 31, 2019 and 2018, the amount of AFUDC recorded was immaterial.
Debt Issuance Costs and Redemption Premiums [Policy Text Block]	Debt Issuance Costs and Redemption Premiums: Original debt issuance costs are deducted from the carrying value of the associated debt liability and amortized over the lives of the respective issues. Premiums paid on the early redemption of debt, which is reacquired through refunding, are deferred and amortized over the life of the debt issued to finance the refunding as GSWC normally receives recovery of these costs in rates.
Advance for Construction and Contributions in Aid [Policy Text Block]	Advances for Construction and Contributions in Aid of Construction: Advances for construction represent amounts advanced by developers for the cost to construct water system facilities in order to extend water service to their properties. Advances are refundable in equal annual installments, generally over 40 years. In certain instances, GSWC makes refunds on these advances over a specific period of time based on operating revenues related to the main or as new customers are connected to receive service from the main.  Contributions in aid of construction are similar to advances but require no refunding. Generally, GSWC and BVESI depreciate contributed property and amortizes contributions in aid of construction at the composite rate of the related property. Utility plant funded by advances and contributions is excluded from rate base.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Instruments : For cash and cash equivalents, accounts receivable, accounts payable and short-term debt, the carrying amount is assumed to approximate fair value due to the short-term nature of the amounts. The table below estimates the fair value of long-term debt issued by GSWC. Rates available to GSWC at December 31, 2020 and 2019 for debt with similar terms and remaining maturities were used to estimate fair value for long-term debt. Changes in the assumptions will produce differing results. 2020 2019 (dollars in thousands) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt—GSWC (1) $ 444,271 $ 559,752 $ 284,699 $ 376,467 (1) Excludes debt issuance costs and redemption premiums. The accounting guidance for fair value measurements applies to all financial assets and financial liabilities that are being measured and reported on a fair value basis. Under the accounting guidance, GSWC makes fair value measurements on its publicly issued notes, private placement notes and other long-term debt using current U.S. corporate bond yields for similar debt instruments. Under the fair value guidance, these are classified as Level 2, which consists of quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. The following table sets forth by level, within the fair value hierarchy, GSWC’s long-term debt measured at fair value as of December 31, 2020: (dollars in thousands) Level 1 Level 2 Level 3 Total Long-term debt—GSWC — $ 559,752 — $ 559,752
Stock-Based Awards [Policy Text Block]	Stock-Based Awards : AWR has issued stock-based awards to its employees under stock incentive plans. AWR has also issued stock-based awards to its Board of Directors under non-employee directors stock plans. Registrant applies the provisions in the accounting guidance for share-based payments in accounting for all of its stock-based awards. See Note 13 for further discussion.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Issued Accounting Pronouncements : Accounting Pronouncements Adopted in 2020 In June 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, and issued further guidance in November 2018 and May 2019 related to the impairment of financial instruments, effective January 1, 2020. The new guidance provides an impairment model, known as the current expected credit loss model, which is based on expected credit losses rather than incurred losses over the remaining life of most financial assets measured at amortized cost, including trade and other receivables. For 2020, Registrant has increased its allowance for doubtful accounts for utility customer accounts receivable, largely due to Registrant's current estimate of the expected associated economic impact of the COVID-19 pandemic (see Note 18). In August 2018, the FASB issued ASU 2018-14, Compensation-Retirement Benefits—Defined Benefit Plans-General (Subtopic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans . This ASU removes disclosures to pension plans and other retirement plans that no longer are considered cost beneficial, clarifies the specific disclosure requirements and adds disclosure requirements deemed relevant. This ASU was adopted by Registrant effective December 31, 2020 and applied on a retrospective basis to all periods presented. The adoption of this guidance did not have a material impact on the Registrant's financial statements and disclosures. Accounting Pronouncements to be Adopted in Future Periods In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes . The amendments in this update simplify the accounting for income taxes by removing certain exceptions and clarifying certain requirements regarding franchise taxes, goodwill, consolidated tax expenses, and annual effective tax rate calculations. The ASU is effective for fiscal years beginning after December 15, 2020. Registrant will adopt this guidance effective January 1, 2021, which is not expected to have a material impact on its financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Public Utility Property, Plant, and Equipment [Table Text Block]	Estimated useful lives of regulated utilities’ utility plant, as authorized by the CPUC, are as follows: Source of water supply 30 years to 50 years Pumping 25 years to 40 years Water treatment 20 years to 35 years Transmission and distribution 25 years to 55 years Generation 40 years Other plant 7 years to 40 years
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]	The table below estimates the fair value of long-term debt issued by GSWC. Rates available to GSWC at December 31, 2020 and 2019 for debt with similar terms and remaining maturities were used to estimate fair value for long-term debt. Changes in the assumptions will produce differing results. 2020 2019 (dollars in thousands) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt—GSWC (1) $ 444,271 $ 559,752 $ 284,699 $ 376,467 (1) Excludes debt issuance costs and redemption premiums.
Fair Value, Liabilities Measured on Recurring Basis [Table Text Block]	The following table sets forth by level, within the fair value hierarchy, GSWC’s long-term debt measured at fair value as of December 31, 2020: (dollars in thousands) Level 1 Level 2 Level 3 Total Long-term debt—GSWC — $ 559,752 — $ 559,752

Revenues (Tables)

Revenues (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue [Table Text Block]	(dollar in thousands) For The Year Ended December 31, 2020 For The Year Ended December 31, 2019 For The Year Ended December 31, 2018 Water: Tariff-based revenues $ 329,670 $ 305,244 298,818 CPUC-approved surcharges (cost-recovery activities) 3,736 4,322 2,962 Other 2,100 2,006 1,813 Water revenues from contracts with customers 335,506 311,572 303,593 WRAM under/(over)-collection (alternative revenue program) (4,869) 8,258 (8,335) Total water revenues 330,637 319,830 295,258 Electric: Tariff-based revenues 35,283 36,628 34,501 CPUC-approved surcharges (cost-recovery activities) 686 410 214 Electric revenues from contracts with customers 35,969 37,038 34,715 BRRAM under/(over)-collection (alternative revenue program) 1,055 2,510 (365) Total electric revenues 37,024 39,548 34,350 Contracted services: Water 74,898 59,868 62,273 Wastewater 45,684 54,623 44,935 Contracted services revenues from contracts with customers 120,582 114,491 107,208 Total revenues $ 488,243 $ 473,869 $ 436,816
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]	The opening and closing balances of the receivable from the U.S. government, contract assets and contract liabilities from contracts with customers, which related entirely to ASUS, are as follows: (dollar in thousands) December 31, 2020 December 31, 2019 Unbilled receivables $ 14,924 $ 10,467 Receivable from the U.S. government $ 74,670 $ 64,819 Contract assets $ 10,257 $ 15,631 Contract liabilities $ 1,800 $ 11,167

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2020
Regulated Operations [Abstract]
Schedule of regulatory assets, less regulatory liabilities in the consolidated balance sheets for continuing operations	: December 31, (dollars in thousands) 2020 2019 GSWC Water Revenue Adjustment Mechanism, net of the Modified Cost Balancing Account $ 13,741 $ 22,535 Costs deferred for future recovery on Aerojet case 6,751 8,292 Pensions and other post-retirement obligations (Note 12) 65,576 40,693 Derivative unrealized loss (Note 5) — 3,171 COVID-19 memorandum account 4,119 — Other regulatory assets 10,670 23,662 Excess deferred income taxes (Note 11) (74,185) (79,886) Flow-through taxes, net (Note 11) (9,722) (12,439) Various refunds to customers (4,577) (8,478) Total GSWC $ 12,373 $ (2,450) BVESI Derivative unrealized loss (Note 5) 1,537 — Other regulatory assets 2,629 — Total AWR $ 16,539 $ (2,450)

Utility Plant and Intangible _2

Utility Plant and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Utility Plant and Intangible Assets
Schedule of Public Utility Property Plant and Equipment Components [Table Text Block]	The following table shows Registrant’s utility plant (regulated utility plant and non-regulated utility property) by major asset class: AWR GSWC (dollars in thousands) 2020 2019 2020 2019 Water Land $ 18,234 $ 18,066 $ 18,234 $ 18,066 Intangible assets 28,906 28,578 28,906 28,578 Source of water supply 92,166 91,685 92,166 91,685 Pumping 190,901 178,058 190,901 178,058 Water treatment 81,272 78,048 81,272 78,048 Transmission and distribution 1,277,361 1,219,285 1,277,361 1,219,285 Other 128,877 117,276 95,562 86,722 1,817,717 1,730,996 1,784,402 1,700,442 Electric (Note 20) Transmission and distribution 87,461 84,018 — 84,018 Generation 12,583 12,583 — 12,583 Other (1) 12,463 11,824 — 11,824 112,507 108,425 — 108,425 Less — accumulated depreciation (568,326) (543,263) (502,283) (531,801) Construction work in progress 150,145 119,547 118,370 117,676 Net utility plant $ 1,512,043 $ 1,415,705 $ 1,400,489 $ 1,394,742 (1) Includes intangible assets of $1.2 million for the years ended December 31, 2020 and 2019 for studies performed in association with the electric segment.
Schedule of components of intangible assets	As of December 31, 2020 and 2019, intangible assets consist of the following: Weighted Average Amortization AWR December 31, GSWC December 31, (dollars in thousands) Period 2020 2019 2020 2019 Intangible assets : Conservation programs 3 years $ 9,486 $ 9,486 $ 9,486 $ 9,486 Water and service rights (2) 30 years 8,694 8,695 8,124 8,124 Water planning studies 14 years 12,141 11,808 10,898 11,808 Total intangible assets 30,321 29,989 28,508 29,418 Less — accumulated amortization (24,460) (24,309) (24,305) (24,166) Intangible assets, net of amortization $ 5,861 $ 5,680 $ 4,203 $ 5,252 Intangible assets not subject to amortization (3) $ 399 $ 402 $ 399 $ 402
Schedule of estimated future consolidated amortization expenses related to intangible assets	Estimated future consolidated amortization expense related to intangible assets for the succeeding five years are (in thousands): Amortization 2021 $ 142 2022 114 2023 114 2024 74 2025 — Total $ 444
Schedule of reconciliation of the beginning and ending aggregate carrying amount of the asset retirement obligations	The following is a reconciliation of the beginning and ending aggregate carrying amount of asset retirement obligations, which are included in “Other Credits” on the balance sheets as of December 31, 2020 and 2019: (dollars in thousands) GSWC Obligation at December 31, 2018 $ 5,228 Additional liabilities incurred 271 Liabilities settled (173) Accretion 86 Revision of previous estimates $ 3,451 Obligation at December 31, 2019 $ 8,863 Additional liabilities incurred 165 Liabilities settled (58) Accretion 350 Obligation at December 31, 2020 $ 9,320

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
GSWC
Derivative instruments
Schedule of changes in the fair value of the derivative	The following table presents changes in the fair value of BVESI’s derivatives for the years 2020 and 2019: (dollars in thousands) 2020 2019 Balance, at beginning of the period $ (3,171) $ (311) Unrealized (loss) gain on purchased power contracts 1,634 (2,860) Balance, at end of the period $ (1,537) $ (3,171)

Earnings Per Share and Capita_2

Earnings Per Share and Capital Stock (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of reconciliation of Registrant's net income and weighted average Common Shares outstanding for calculating basic net income per share	The following is a reconciliation of Registrant’s net income and weighted average Common Shares outstanding for calculating basic net income per share: Basic: For The Years Ended December 31, (in thousands, except per share amounts) 2020 2019 2018 Net income $ 86,425 $ 84,342 $ 63,871 Less: (a) Distributed earnings to common shareholders 47,206 42,702 38,937 Distributed earnings to participating securities 158 180 204 Undistributed earnings 39,061 41,460 24,730 (b) Undistributed earnings allocated to common shareholders 38,930 41,285 24,601 Undistributed earnings allocated to participating securities 131 175 129 Total income available to common shareholders, basic (a)+(b) $ 86,136 $ 83,987 $ 63,538 Weighted average Common Shares outstanding, basic 36,880 36,814 36,733 Basic earnings per Common Share $ 2.34 $ 2.28 $ 1.73
Schedule of reconciliation of Registrant's net income and weighted average Common Shares outstanding for calculating diluted net income per share	The following is a reconciliation of Registrant’s net income and weighted average Common Shares outstanding for calculating diluted net income per share: Diluted: For The Years Ended December 31, (in thousands, except per share amounts) 2020 2019 2018 Common shareholders earnings, basic $ 86,136 $ 83,987 $ 63,538 Undistributed earnings for dilutive stock options and restricted stock units 131 175 129 Total common shareholders earnings, diluted $ 86,267 $ 84,162 $ 63,667 Weighted average Common Shares outstanding, basic 36,880 36,814 36,733 Stock-based compensation (1) 115 150 203 Weighted average Common Shares outstanding, diluted 36,995 36,964 36,936 Diluted earnings per Common Share $ 2.33 $ 2.28 $ 1.72 (1) In applying the treasury stock method of reflecting the dilutive effect of outstanding stock-based compensation in the calculation of diluted EPS, 127,298 restricted stock units, including performance awards, at December 31, 2020 were deemed to be outstanding in accordance with accounting guidance on earnings per share.

Bank Debt (Tables)

Bank Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Bank Debt
Schedule of Short-term Debt [Table Text Block]	Registrant’s borrowing activities (excluding letters of credit) for the years ended December 31, 2020 and 2019 were as follows: December 31, (in thousands, except percent) 2020 2019 Balance Outstanding at December 31, $ 134,200 $ 205,000 Interest Rate at December 31, 1.19% ~ 1.90% 2.44 % Average Amount Outstanding $ 162,995 $ 167,392 Weighted Average Annual Interest Rate 1.47 % 2.88 % Maximum Amount Outstanding $ 249,200 $ 205,500 AWR’s (parent) borrowing activities (excluding letters of credit) for the years ended December 31, 2020 and 2019 were as follows: December 31, (in thousands, except percent) 2020 2019 Balance Outstanding at December 31, $ 114,000 $ 205,000 Interest Rate at December 31, 1.19 % 2.44 % Average Amount Outstanding 160,495 $ 167,392 Weighted Average Annual Interest Rate 1.47 % 2.88 % Maximum Amount Outstanding $ 249,000 $ 205,500

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of annual maturities of all long-term debt, including capitalized leases	Annual maturities of all long-term debt at December 31, 2020 are as follows (in thousands): 2021 $ 358 2022 382 2023 406 2024 430 2025 449 Thereafter 442,246 Total $ 444,271

Taxes on Income (Tables)

Taxes on Income (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of significant components of the deferred tax assets and liabilities from continuing operations	The significant components of the deferred tax assets and liabilities as reflected in the balance sheets at December 31, 2020 and 2019 are: AWR GSWC December 31, December 31, (dollars in thousands) 2020 2019 2020 2019 Deferred tax assets: Regulatory-liability-related (1) $ 32,640 $ 33,080 $ 30,782 $ 33,080 Contributions and advances 6,390 5,777 6,771 6,158 Other 6,092 5,792 6,663 6,618 Total deferred tax assets $ 45,122 $ 44,649 $ 44,216 $ 45,856 Deferred tax liabilities: Fixed assets $ (146,688) $ (144,444) $ (141,422) $ (147,759) Regulatory-asset-related: depreciation and other (22,205) (20,641) (21,060) (20,641) Balancing and memorandum accounts (non-flow-through) (7,401) (4,868) (6,315) (5,262) Total deferred tax liabilities (176,294) (169,953) (168,797) (173,662) Accumulated deferred income taxes - net $ (131,172) $ (125,304) $ (124,581) $ (127,806)
Schedule of current and deferred components of income tax expense from continuing operations	The current and deferred components of income tax expense are as follows: AWR Year Ended December 31, (dollars in thousands) 2020 2019 2018 Current Federal $ 19,240 $ 12,507 $ 17,252 State 6,714 5,540 6,538 Total current tax expense $ 25,954 $ 18,047 $ 23,790 Deferred Federal $ 1,814 $ 6,407 $ (4,334) State 429 216 (1,439) Total deferred tax (benefit) expense 2,243 6,623 (5,773) Total income tax expense $ 28,197 $ 24,670 $ 18,017 GSWC Year Ended December 31, (dollars in thousands) 2020 2019 2018 Current Federal $ 14,674 $ 9,616 $ 14,488 State 5,849 5,480 5,932 Total current tax expense $ 20,523 $ 15,096 $ 20,420 Deferred Federal $ 949 $ 4,924 $ (5,531) State 232 157 (1,286) Total deferred tax (benefit) expense 1,181 5,081 (6,817) Total income tax expense $ 21,704 $ 20,177 $ 13,603
Schedule of reconciliations of the effective tax rates to the federal statutory rate	The reconciliations of the effective tax rates to the federal statutory rate are as follows: AWR Year Ended December 31, (dollars in thousands) 2020 2019 2018 Federal taxes on pretax income at statutory rate $ 24,071 $ 22,872 $ 17,196 Increase (decrease) in taxes resulting from: State income tax, net of federal benefit 5,764 4,758 3,693 Excess deferred tax amortization (1,550) (1,579) (2,101) Flow-through on fixed assets 1,056 1,244 429 Flow-through on removal costs (1,031) (1,582) (1,445) Investment tax credit (71) (71) (69) Other – net (42) (972) 314 Total income tax expense from operations $ 28,197 $ 24,670 $ 18,017 Pretax income from operations $ 114,622 $ 109,012 $ 81,888 Effective income tax rate 24.6 % 22.6 % 22.0 % GSWC Year Ended December 31, (dollars in thousands) 2020 2019 2018 Federal taxes on pretax income at statutory rate $ 18,202 $ 18,236 $ 12,939 Increase (decrease) in taxes resulting from: State income tax, net of federal benefit 4,920 4,656 3,335 Excess deferred tax amortization (1,477) (1,579) (2,101) Flow-through on fixed assets 1,042 1,244 429 Flow-through on removal costs (1,026) (1,582) (1,445) Investment tax credit (71) (71) (69) Other – net 114 (727) 515 Total income tax expense from operations $ 21,704 $ 20,177 $ 13,603 Pretax income from operations $ 86,675 $ 86,840 $ 61,615 Effective income tax rate 25.0 % 23.2 % 22.1 %

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Employee benefit plans
Schedule of Pension Plan's funded status and amounts recognized in balance sheets and the components of net pension cost and accrued post-retirement liability	The following table sets forth the Pension Plan’s and post-retirement medical plan’s funded status and amounts recognized in Registrant’s balance sheets and the components of net pension cost and accrued liability at December 31, 2020 and 2019: Pension Benefits Post-Retirement Medical (dollars in thousands) 2020 2019 2020 2019 Change in Projected Benefit Obligation: Projected benefit obligation at beginning of year $ 231,852 $ 196,082 $ 7,395 $ 7,886 Service cost 5,558 4,441 171 186 Interest cost 7,880 8,527 208 285 Actuarial (gain) loss 35,453 29,784 (1,604) (538) Benefits/expenses paid (7,957) (6,982) (264) (424) Projected benefit obligation at end of year $ 272,786 $ 231,852 $ 5,906 $ 7,395 Changes in Plan Assets: Fair value of plan assets at beginning of year $ 192,477 $ 162,529 $ 11,271 $ 10,010 Actual return on plan assets 24,909 33,018 1,307 1,685 Employer contributions 3,718 3,913 269 170 Benefits/expenses paid (7,957) (6,983) (534) (594) Fair value of plan assets at end of year $ 213,147 $ 192,477 $ 12,313 $ 11,271 Funded Status: Net amount recognized as accrued pension cost $ (59,639) $ (39,375) $ 6,407 $ 3,876 The increase in the underfunded status of the pension was due primarily to a decrease in the discount rate, which decreased from 3.43% as of December 31, 2019 to 2.55% as of December 31, 2020 as noted in the following tables. Pension Benefits Post-Retirement (dollars in thousands) 2020 2019 2020 2019 Amounts recognized on the balance sheets: Non-current assets $ — $ — $ 6,407 $ 3,876 Current liabilities — — — — Non-current liabilities (59,639) (39,375) — — Net amount recognized $ (59,639) $ (39,375) $ 6,407 $ 3,876 Amounts recognized in regulatory assets consist of: Prior service cost (credit) $ 2,757 $ 3,191 $ — $ — Net (gain) loss 57,716 37,309 (6,855) (5,432) Regulatory assets (liabilities) 60,473 40,500 (6,855) (5,432) Unfunded accrued pension cost (834) (1,125) 448 1,556 Net liability (asset) recognized $ 59,639 $ 39,375 $ (6,407) $ (3,876) Changes in plan assets and benefit obligations recognized in regulatory assets: Regulatory asset at beginning of year $ 40,500 $ 35,213 $ (5,432) $ (4,459) Net loss (gain) 22,343 7,140 (2,400) (1,775) New prior service cost — — — — Amortization of prior service (cost) credit (435) (434) — — Amortization of net gain (loss) (1,935) (1,419) 977 802 Total change in regulatory asset 19,973 5,287 (1,423) (973) Regulatory asset (liability) at end of year $ 60,473 $ 40,500 $ (6,855) $ (5,432) Net periodic pension costs $ 4,010 $ 4,447 $ (1,108) $ (779) Change in regulatory asset 19,973 5,287 (1,423) (973) Total recognized in net periodic pension cost and regulatory asset (liability) $ 23,983 $ 9,734 $ (2,531) $ (1,752) Additional year-end information for plans with an accumulated benefit obligation in excess of plan assets: Projected benefit obligation $ 272,786 $ 231,852 $ 5,906 $ 7,395 Accumulated benefit obligation $ 253,108 $ 215,996 N/A N/A Fair value of plan assets $ 213,147 $ 192,477 $ 12,313 $ 11,271 Weighted-average assumptions used to determine benefit obligations at December 31: Discount rate 2.55 % 3.43 % 2.20 % 3.12 % Rate of compensation increase * * N/A N/A • Age-graded ranging from 3.0% to 8.0%.
Schedule of components of net periodic pension and post-retirement benefits cost, before allocation to the overhead pool	The components of net periodic pension and post-retirement benefits cost, before allocation to the overhead pool, for 2020, 2019 and 2018 are as follows: Pension Benefits Post-Retirement (dollars in thousands, except percent) 2020 2019 2018 2020 2019 2018 Components of Net Periodic Benefits Cost: Service cost $ 5,558 $ 4,441 $ 5,342 $ 171 $ 186 $ 218 Interest cost 7,880 8,527 7,646 208 285 292 Expected return on plan assets (11,798) (10,374) (11,172) (510) (449) (493) Amortization of prior service cost (credit) 435 434 — — — Amortization of actuarial (gain) loss 1,935 1,419 1,254 (977) (801) (769) Net periodic pension cost under accounting standards $ 4,010 $ 4,447 $ 3,070 $ (1,108) $ (779) $ (752) Regulatory adjustment (483) (593) — — — — Total expense recognized, before surcharges and allocation to overhead pool $ 3,527 $ 3,854 $ 3,070 $ (1,108) $ (779) $ (752) Weighted-average assumptions used to determine net periodic cost: Discount rate 3.43 % 4.43 % 3.76 % 3.12 % 4.20 % 3.52 % Expected long-term return on plan assets 6.25 % 6.50 % 6.50 % * * * Rate of compensation increase ** ** ** N/A N/A N/A *6.0% for union plan and 4.2% for non-union (net of income taxes) in 2020, 2019 and 2018. ** Age-graded ranging from 3.0% to 8.0%.
Schedule of actual allocation of plan assets	The Committee approves the target asset allocations. Registrant’s pension and post-retirement plan weighted-average asset allocations at December 31, 2020 and 2019, by asset category are as follows: Pension Benefits Post-Retirement Asset Category 2020 2019 2020 2019 Actual Asset Allocations : Equity securities 59 % 56 % 63 % 61 % Debt securities 36 % 39 % 36 % 38 % Real Estate Funds 5 % 5 % — % — % Cash equivalents — % — % 1 % 1 % Total 100 % 100 % 100 % 100 %
Schedule of pension and post-retirement plan target asset allocations	Equity securities did not include AWR’s Common Shares as of December 31, 2020 and 2019. Target Asset Allocations: Pension Benefits Post-retirement Equity securities 60 % 60 % Debt securities 40 % 40 % Total 100 % 100 %
Summary of fair value, measured by net asset value, of the pension investment assets	The following tables set forth the fair value, measured by net asset value, of the pension investment assets as of December 31, 2020 and 2019: Net Asset Value as of December 31, 2020 (dollars in thousands) Fair Value Unfunded Commitments Redemption Frequency Redemption Notice Period Cash equivalents $ 589 — N/A N/A Fixed income fund $ 76,221 — Daily Daily Equity securities : U.S. small/mid cap funds 21,837 — Daily Daily U.S. large cap funds 53,677 — Daily Daily International funds 50,488 — Daily Daily Total equity funds 126,002 — Real estate funds 10,335 — Daily Daily Total $ 213,147 — Net Asset Value as of December 31, 2019 (dollars in thousands) Fair Value Unfunded Commitments Redemption Frequency Redemption Notice Period Cash equivalents $ 600 — N/A N/A Fixed income fund 74,123 — Daily Daily Equity securities : U.S. small/mid cap funds 17,865 — Daily Daily U.S. large cap funds 47,132 — Daily Daily International funds 43,778 — Daily Daily Total equity funds 108,775 Real estate funds 8,979 — Daily Daily Total $ 192,477 —
Schedule of pension and post-retirement plans' investment assets measured at fair value	The following tables set forth by level, within the fair value hierarchy, the post-retirement plan's investment assets measured at fair value as of December 31, 2020 and 2019: Fair Value as of December 31, 2020 (dollars in thousands) Level 1 Level 2 Level 3 Total Fair Value of Post-Retirement Plan Assets: Cash equivalents $ 169 — — $ 169 Fixed income 4,436 — — 4,436 U.S. equity securities 7,707 — — 7,707 Total investments measured at fair value $ 12,312 — — $ 12,312 Fair Value as of December 31, 2019 (dollars in thousands) Level 1 Level 2 Level 3 Total Fair Value of Post-Retirement Plan Assets: Cash equivalents $ 69 — — $ 69 Fixed income 4,279 — — 4,279 U.S. equity securities 6,923 — — 6,923 Total investments measured at fair value $ 11,271 — — $ 11,271
Schedule of estimated future benefit payments	Estimated future benefit payments at December 31, 2020 for the next five years and thereafter are as follows (in thousands): Pension Benefits Post-Retirement Medical Benefits 2021 $ 8,572 $ 486 2022 9,262 503 2023 9,880 516 2024 10,494 489 2025 11,142 476 Thereafter 63,680 1,813 Total $ 113,030 $ 4,283
SERP
Employee benefit plans
Schedule of Pension Plan's funded status and amounts recognized in balance sheets and the components of net pension cost and accrued post-retirement liability	The following provides a reconciliation of benefit obligations, funded status of the SERP, as well as a summary of significant estimates at December 31, 2020 and 2019: (dollars in thousands) 2020 2019 Change in Benefit Obligation: Benefit obligation at beginning of year $ 29,703 $ 24,517 Service cost 1,029 1,193 Interest cost 988 1,069 Actuarial (gain) loss 5,479 3,419 Benefits paid (597) (495) Benefit obligation at end of year $ 36,602 $ 29,703 Changes in Plan Assets: Fair value of plan assets at beginning and end of year — — Funded Status: Net amount recognized as accrued cost $ (36,602) $ (29,703) (in thousands) 2020 2019 Amounts recognized on the balance sheets: Current liabilities $ (602) $ (609) Non-current liabilities (36,000) (29,094) Net amount recognized $ (36,602) $ (29,703) Amounts recognized in regulatory assets consist of: Prior service cost $ — $ — Net loss 12,988 8,352 Regulatory assets 12,988 8,352 Unfunded accrued cost 23,614 21,351 Net liability recognized $ 36,602 $ 29,703 Changes in plan assets and benefit obligations recognized in regulatory assets consist of: Regulatory asset at beginning of year $ 8,352 $ 5,403 Net (gain) loss 5,479 3,419 Amortization of prior service credit — — Amortization of net loss (843) (470) Total change in regulatory asset 4,636 2,949 Regulatory asset at end of year $ 12,988 $ 8,352 Net periodic pension cost $ 2,860 $ 2,733 Change in regulatory asset 4,636 2,949 Total recognized in net periodic pension and regulatory asset $ 7,496 $ 5,682 Additional year-end information for plans with an accumulated benefit obligation in excess of plan assets: Projected benefit obligation $ 36,602 $ 29,703 Accumulated benefit obligation 30,428 26,251 Fair value of plan assets — — Weighted-average assumptions used to determine benefit obligations: Discount rate 2.52 % 3.36 % Rate of compensation increase 4.00 % 4.00 %
Schedule of components of net periodic pension and post-retirement benefits cost, before allocation to the overhead pool	The components of SERP expense, before allocation to the overhead pool, for 2020, 2019 and 2018 are as follows: (dollars in thousands, except percent) 2020 2019 2018 Components of Net Periodic Benefits Cost: Service cost $ 1,029 $ 1,193 $ 1,096 Interest cost 988 1,069 888 Amortization of prior service cost — — — Amortization of net loss 843 471 1,049 Net periodic pension cost $ 2,860 $ 2,733 $ 3,033 Weighted-average assumptions used to determine net periodic cost: Discount rate 3.36 % 4.40 % 3.72 % Rate of compensation increase 4.00 % 4.00 % 4.00 %
Schedule of pension and post-retirement plans' investment assets measured at fair value	The following tables set forth by level, within the fair value hierarchy, the Rabbi Trust investment assets measured at fair value as of December 31, 2020 and 2019: Fair Value as of December 31, 2020 (dollars in thousands) Level 1 Level 2 Level 3 Total Fair Value of Assets held in Rabbi Trust: Cash equivalents $ 8 — — $ 8 Fixed income securities 10,201 — — 10,201 Equity securities 15,703 — — 15,703 Total investments measured at fair value $ 25,912 — — $ 25,912 Fair Value as of December 31, 2019 (dollars in thousands) Level 1 Level 2 Level 3 Total Fair Value of Assets held in Rabbi Trust: Cash equivalents $ 72 — — $ 72 Fixed income securities 8,427 — — 8,427 Equity securities 13,054 — — 13,054 Total investments measured at fair value $ 21,553 — — $ 21,553
Schedule of estimated future benefit payments	Estimated future benefit payments for the SERP at December 31, 2020 for the next five years and thereafter are as follows (in thousands): 2021 $ 602 2022 792 2023 787 2024 1,039 2025 1,029 Thereafter 11,937 Total $ 16,186

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Schedule of share-based compensation expenses	The following table presents share-based compensation expenses for the years ended December 31, 2020, 2019 and 2018. These expenses resulting from restricted stock units, including performance awards, are included in administrative and general expenses in AWR's and GSWC’s statements of income: AWR GSWC For The Years Ended December 31, For The Years Ended December 31, (in thousands) 2020 2019 2018 2020 2019 2018 Stock-based compensation related to: Restricted stock units $ 2,463 $ 2,517 $ 3,851 $ 2,349 $ 2,253 $ 3,397 Total stock-based compensation expense $ 2,463 $ 2,517 $ 3,851 $ 2,349 $ 2,253 $ 3,397
Schedule of assumptions used to estimate fair value of each option grant on the grant date using the Black-Scholes option-pricing model	will be earned based on Registrant’s TSR compared to the TSR for a specific peer group of investor-owned water companies. A summary of the status of Registrant’s outstanding performance awards to officers as of December 31, 2020, and changes during the year ended December 31, 2020, is presented below: Number of Weighted Average Performance awards at January 1, 2020 84,649 $ 51.85 Granted 16,375 89.15 Performance criteria adjustment (670) 38.14 Vested (41,434) 44.80 Forfeited (960) 82.47 Performance awards at December 31, 2020 57,960 $ 66.40
Summary of the status of Registrant's outstanding restricted stock units to employees and directors	A summary of the status of Registrant’s outstanding RSUs, excluding performance awards, to employees and directors as of December 31, 2020, and changes during the year ended December 31, 2020, is presented below: Number of Weighted Average Restricted share units at January 1, 2020 75,071 $ 46.92 Granted 19,307 86.41 Vested (23,713) 58.56 Forfeited (1,326) 78.24 Restricted share units at December 31, 2020 69,339 $ 53.33

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2020
Risks and Uncertainties [Abstract]
Schedule of estimated future minimum payments under purchased water supply commitments	GSWC’s estimated future minimum payments under these purchased water supply commitments at December 31, 2020 are as follows (in thousands): 2021 $ 426 2022 426 2023 426 2024 426 2025 383 Thereafter 1,675 Total $ 3,762

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Supplemental lease information	Registrant's supplemental lease information for the year ended December 31, 2020 is as follows (in thousands, except for weighted average data): For The Year Ended December 31, 2020 For The Year Ended December 31, 2019 Operating lease costs $2,873 $3,166 Short-term lease costs 143 159 Weighted average remaining lease term (in years) 6.62 7.24 Weighted-average discount rate 3.6% 3.5% Non-cash transactions Lease liabilities arising from obtaining right-of-use assets $27 $18,034
Maturities of operating lease liabilities	.Registrant’s future minimum payments under long-term non-cancelable operating leases are as follows (in thousands): December 31, 2020 2021 $ 2,561 2022 2,318 2023 1,825 2024 1,503 2025 1,324 Thereafter 3,925 Total lease payments 13,456 Less: imputed interest 1,807 Total lease obligations 11,649 Less: current obligations 2,013 Long-term lease obligations $ 9,636

Business Segments (Tables)

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule of reporting segments information	Capital additions reflect capital expenditures paid in cash and exclude U.S. government-funded and third-party prime funded capital expenditures for ASUS and property installed by developers and conveyed to GSWC and BVESI. As Of And For The Year Ended December 31, 2020 AWR Consolidated (dollars in thousands) Water Electric ASUS Parent AWR Operating revenues $ 330,637 $ 37,024 $ 120,582 $ — $ 488,243 Operating income (loss) 97,896 10,303 22,309 (9) 130,499 Interest expense, net 20,312 584 (496) 330 20,730 Utility Plant 1,400,489 89,308 22,246 — 1,512,043 Depreciation and amortization expense (1) 30,969 2,479 3,402 — 36,850 Income tax expense (benefit) 20,515 2,689 5,201 (208) 28,197 Capital additions 107,355 18,393 4,675 — 130,423 As Of And For The Year Ended December 31, 2019 GSWC AWR Consolidated (dollars in thousands) Water Electric ASUS Parent AWR Operating revenues $ 319,830 $ 39,548 $ 114,491 $ — $ 473,869 Operating income (loss) 93,895 11,197 21,990 (9) 127,073 Interest expense, net 20,304 1,228 (734) 539 21,337 Utility Plant 1,322,062 72,680 20,963 — 1,415,705 Depreciation and amortization expense (1) 29,956 2,485 2,956 — 35,397 Income tax expense/(benefit) 17,295 2,882 5,202 (709) 24,670 Capital additions 131,353 11,499 9,088 — 151,940 As Of And For The Year Ended December 31, 2018 GSWC AWR Consolidated (dollars in thousands) Water Electric ASUS Parent AWR Operating revenues $ 295,258 $ 34,350 $ 107,208 $ — $ 436,816 Operating income 74,342 6,220 20,414 7 100,983 Interest expense, net 18,403 1,328 (327) 451 19,855 Utility Plant 1,218,468 62,624 15,218 — 1,296,310 Depreciation and amortization expense (1) 36,137 2,258 2,030 — 40,425 Income tax expense/(benefit) 12,391 1,212 4,939 (525) 18,017 Capital additions 110,934 5,420 10,207 — 126,561
Schedule of reconciliation of total utility plant (a key figure for rate-making) to total consolidated assets	The following table reconciles total utility plant (a key figure for rate-making) to total consolidated assets (in thousands): December 31, 2020 2019 Total utility plant $ 1,512,043 $ 1,415,705 Other assets 279,560 225,626 Total consolidated assets $ 1,791,603 $ 1,641,331

Allowance for Doubtful Accoun_2

Allowance for Doubtful Accounts (Tables)	12 Months Ended
	Dec. 31, 2020
Allowance for Doubtful Accounts
Schedule of provision for doubtful accounts charged to expense and accounts written off, net of recoveries	The table below presents Registrant’s provision for doubtful accounts charged to expense and accounts written off, net of recoveries. Provisions included in 2020, 2019, and 2018 for AWR and GSWC are as follows: AWR December 31, (dollars in thousands) 2020 2019 2018 Balance at beginning of year $ 916 $ 951 $ 1,041 Provision charged to expense 5,016 609 841 Accounts written off, net of recoveries (616) (644) (931) Balance at end of year $ 5,316 $ 916 $ 951 Allowance for doubtful accounts related to accounts receivable-customer $ 5,263 $ 857 $ 892 Allowance for doubtful accounts related to other accounts receivable 53 59 59 Total allowance for doubtful accounts $ 5,316 $ 916 $ 951 GSWC December 31, (dollars in thousands) 2020 2019 2018 Balance at beginning of year $ 916 $ 951 $ 865 Provision charged to expense 4,703 607 850 Balance transfer to BVESI (Note 20) (79) — — Accounts written off, net of recoveries (580) (642) (764) Balance at end of year $ 4,960 $ 916 $ 951 Allowance for doubtful accounts related to accounts receivable-customer $ 4,907 $ 857 $ 892 Allowance for doubtful accounts related to other accounts receivable 53 59 59 Total allowance for doubtful accounts $ 4,960 $ 916 $ 951

Statement of Cash Flows, Supp_2

Statement of Cash Flows, Supplemental Disclosures (Tables)	12 Months Ended
	Dec. 31, 2020
Supplemental Cash Flow Elements [Abstract]
Schedule of non-cash financing and investing activities and other cash flow information	The following table sets forth non-cash financing and investing activities and other cash flow information (in thousands). AWR GSWC December 31, December 31, 2020 2019 2018 2020 2019 2018 Taxes and Interest Paid: Income taxes paid, net $ 13,684 $ 22,496 $ 21,084 $ 8,184 $ 17,206 $ 19,448 Interest paid, net of capitalized interest 19,941 25,080 23,471 19,681 23,925 22,721 Non-Cash Transactions: Accrued payables for investment in utility plant 27,861 23,736 27,403 25,633 23,736 27,403 Property installed by developers and conveyed 3,102 6,220 2,082 3,102 6,220 2,082 Transfer of electric segment net assets (net of cash) for BVESI common shares (Note 20) — — — 71,324 — — Distribution of BVESI common shares to AWR parent (Note 20) — — — 71,344 — —

Completion of Electric Utilit_2

Completion of Electric Utility Reorganization Plan (Tables)	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
Completion of Electric Utility Reorganization Plan-selected information for the results of operations and its cashflow	The table below sets forth selected information relating to the electric segment's results of operations for the six months ended December 31, 2020 and 2019, and its cash flows for the six months ended December 31, 2020 (in thousands): Six Months Ended December 31, 2020 2019 (1) (Subsidiary of AWR) (Division of GSWC) Electric revenues $ 18,377 $ 21,510 Operating expenses 13,074 13,153 Operating income 5,303 8,357 Net income $ 3,870 $ 5,422 Six Months Ended December 31, 2020 (Subsidiary of AWR) Net cash provided from operating activities $ 1,887 Net cash used in investing activities (capital expenditures) (9,339) Net cash provided from financing activities (2) 7,799 Net change in cash and cash equivalents 347 Cash and cash equivalents, beginning of period 20 Cash and cash equivalents, end of period $ 367 (1) Operating income for the six months ended December 31, 2019 included the retroactive impact of the CPUC's August 2019 final decision on the electric general rate case, which totaled approximately $3.7 million for periods prior to July 1, 2019. (2) Effective July 1, 2020, BVESI entered into a 3-year, $35.0 million revolving credit facility agreement with a bank and began borrowing under this facility. As of December 31, 2020, there was $20.2 million outstanding under this new facility. Under the terms of the credit agreement, BVESI has the option to request an increase in the facility by an additional $15.0 million. Offsetting the increase from borrowings under this credit facility was dividends in the amount of $12.4 million that were paid to AWR by BVESI during the fourth quarter of 2020.

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Data [Abstract]
Quarterly Financial Information	Registrant's business is seasonal, and it is management’s opinion that comparisons of earnings for the quarterly periods do not reflect overall trends and changes in Registrant’s operations. AWR For The Year Ended December 31, 2020 (in thousands, except per share amounts) First Second Third Fourth Year Operating revenues $ 109,077 $ 121,278 $ 133,688 $ 124,200 $ 488,243 Operating income 25,699 35,716 39,807 29,277 130,499 Net income 14,072 25,612 26,530 20,211 86,425 Basic earnings per share 0.38 0.69 0.72 0.55 2.34 Diluted earnings per share 0.38 0.69 0.72 0.54 2.33 GSWC For The Year Ended December 31, 2020 (in thousands) First Second Third Fourth Year (1) Operating revenues $ 82,392 $ 94,753 $ 98,701 $ 73,438 $ 349,284 Operating income 22,092 30,175 33,149 17,480 102,896 Net income 11,202 20,919 21,143 11,707 64,971 AWR For The Year Ended December 31, 2019 (in thousands, except per share amounts) First Second Third Fourth Year Operating revenues $ 101,733 $ 124,647 $ 134,496 $ 112,993 $ 473,869 Operating income 20,195 39,430 42,724 24,724 127,073 Net income 12,852 26,784 28,006 16,700 84,342 Basic earnings per share 0.35 0.72 0.76 0.45 2.28 Diluted earnings per share 0.35 0.72 0.76 0.45 2.28 GSWC For The Year Ended December 31, 2019 (in thousands) First Second Third Fourth Year Operating revenues $ 75,352 $ 95,548 $ 107,245 $ 81,233 $ 359,378 Operating income 15,327 34,037 36,982 18,746 105,092 Net income 9,022 22,298 23,362 11,981 66,663 (1) As a result of GSWC's transfer of electric net assets to BVESI, from July 1, 2020 onward, operating results of the electric segment are no longer included in GSWC's financial statements, but continue to be included in AWR's consolidated financial statements. GSWC's operating revenues, operating income and net income for 2020 includes the electric segment's results through June 30, 2020. (2) The second quarter of 2019 includes approximately $4.0 million of operating income related to the first quarter of 2019 as a result of the final CPUC decision on the water general rate case, which was received in May 2019 and was retroactive to January 1, 2019. (3) The third quarter of 2019 includes the retroactive impact of the final decision on the electric general rate case approved by the CPUC in August 2019, which was retroactive to January 1, 2018. Included in the third quarter of 2019 results are approximately $1.4 million of pretax income related to the first two quarters of 2019 and approximately $2.3 million of pretax income related to 2018.

SEC Schedule, Article 12-04, Co

SEC Schedule, Article 12-04, Condensed Financial Information of Registrant (Tables)	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Schedule of Short-term Debt [Table Text Block]	Registrant’s borrowing activities (excluding letters of credit) for the years ended December 31, 2020 and 2019 were as follows: December 31, (in thousands, except percent) 2020 2019 Balance Outstanding at December 31, $ 134,200 $ 205,000 Interest Rate at December 31, 1.19% ~ 1.90% 2.44 % Average Amount Outstanding $ 162,995 $ 167,392 Weighted Average Annual Interest Rate 1.47 % 2.88 % Maximum Amount Outstanding $ 249,200 $ 205,500 AWR’s (parent) borrowing activities (excluding letters of credit) for the years ended December 31, 2020 and 2019 were as follows: December 31, (in thousands, except percent) 2020 2019 Balance Outstanding at December 31, $ 114,000 $ 205,000 Interest Rate at December 31, 1.19 % 2.44 % Average Amount Outstanding 160,495 $ 167,392 Weighted Average Annual Interest Rate 1.47 % 2.88 % Maximum Amount Outstanding $ 249,000 $ 205,500

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2020USD ($)customerregistrantshares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)shares
Nature of Operations:
Number of customers served | customer	1,000,000
Number of States in which Entity Operates	9
Number of registrants filing combined report | registrant	2
Related Party Transactions
Related Party Transaction, Amounts of Transaction	$ 4,900,000	$ 4,700,000	$ 4,200,000
Exercise of stock options and other issuance of Common Shares	30,000	519,000	546,000
Line of Credit Facility, Current Borrowing Capacity	200,000,000
Regulatory Asset CEMA	4,400,000
Impairment of Long-Lived Assets
Asset Retirement Obligation, Legally Restricted Assets, Fair Value	0
Impairment of long-lived assets	0	0	0
Goodwill
Goodwill arose from acquisition of subcontractor's business	$ 1,100,000	1,100,000
Advances for Construction and Contributions in aid of Constructions
Period for refund of advances for construction	40 years
Fair Value of Financial Instruments
Short-term Debt, Terms	24
Common Stock [Member]
Related Party Transactions
Exercise of stock options and other issuance of Common Shares	$ 30,000	$ 519,000	$ 546,000
Stock Issued During Period, Shares, New Issues | shares	42,000	89,000	77,000
GSWC
Related Party Transactions
Exercise of stock options and other issuance of Common Shares	$ 60,000,000		$ 47,500,000
Due to Related Parties	0
Regulatory Asset CEMA	$ 4,100,000
Property and Depreciation
Aggregate composite rate for depreciation (as a percent)	2.20%	2.20%	2.70%
Depreciation	$ 32,900,000	$ 31,700,000	$ 37,300,000
Depreciation on transportation equipment	$ 353,000	316,000	238,000
Estimated useful lives of utility plant, as authorized by the CPUC
Generation	40 years
Fair Value of Financial Instruments
Long-term debt-GSWC	$ 559,752,000
GSWC | Level 1
Fair Value of Financial Instruments
Long-term debt-GSWC	0
GSWC | Level 3
Fair Value of Financial Instruments
Long-term debt-GSWC	0
GSWC | Carrying Amount
Fair Value of Financial Instruments
Long-term debt-GSWC	444,271,000	284,699,000
GSWC | Fair Value
Fair Value of Financial Instruments
Long-term debt-GSWC		$ 376,467,000
GSWC | Fair Value | Level 2
Fair Value of Financial Instruments
Long-term debt-GSWC	$ 559,752,000
GSWC | Minimum
Estimated useful lives of utility plant, as authorized by the CPUC
Source of water supply	30 years
Pumping	25 years
Water treatment	20 years
Transmission and Distribution	25 years
Other plant	7 years
GSWC | Maximum
Estimated useful lives of utility plant, as authorized by the CPUC
Source of water supply	50 years
Pumping	40 years
Water treatment	35 years
Transmission and Distribution	55 years
Other plant	40 years
GSWC | Common Stock [Member]
Related Party Transactions
Exercise of stock options and other issuance of Common Shares	$ 60,000,000		$ 47,500,000
Stock Issued During Period, Shares, New Issues | shares	5	0	19
Bear Valley Electric Service, Inc.
Related Party Transactions
Related Party Transaction, Amounts of Transaction	$ 1,300,000
Regulatory Asset CEMA	295,000
Interest
Public Utilities, Allowance for Funds Used During Construction, Additions	200,000
Parent [Member]
Related Party Transactions
Line of Credit Facility, Current Borrowing Capacity	30,000,000
Notes Receivable, Related Parties	6,000,000
Notes Payable, Related Parties	$ 0
Water: | GSWC
Nature of Operations:
Number of customers served | customer	261,800
Electric: | Bear Valley Electric Service, Inc.
Nature of Operations:
Number of customers served | customer	24,500
Contracted services: | American States Utility Services [Member]
Nature of Operations:
Period of fixed price contracts to operate and maintain the water and/or wastewater systems at various military bases	50 years

Revenues (Details)

Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue, Performance Obligation, Payment Terms	20 days
Cost of services	$ 62,411	$ 55,673	$ 53,906
GSWC
Disaggregation of Revenue [Line Items]
Period within which Expected Additional Revenue Collection is Recorded Subject to Undercollection of Revenue	24 months
Contracted services: | American States Utility Services [Member]
Disaggregation of Revenue [Line Items]
Period of Fixed Price Contracts to Operate and Maintain Water Systems at Various Military Bases	50 years
Sales [Member] | Water: | GSWC
Disaggregation of Revenue [Line Items]
Percentage of total revenues	90.00%
Sales [Member] | Electric: | Golden State Water Company and Bear Valley Electric Service, Inc. [Member]
Disaggregation of Revenue [Line Items]
Percentage of total revenues	90.00%
Franchisor | GSWC
Disaggregation of Revenue [Line Items]
Cost of services	$ 3,800	$ 4,000	$ 3,600

Revenues Disaggregation of Reve

Revenues Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended								6 Months Ended	12 Months Ended
	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2020USD ($)unit	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Disaggregation of Revenue [Line Items]
Electric										$ 37,024	$ 39,548	$ 34,350
Operating revenues	$ 124,200	$ 133,688	$ 121,278	$ 109,077	$ 112,993	$ 134,496	$ 124,647	$ 101,733		488,243	473,869	436,816
GSWC
Disaggregation of Revenue [Line Items]
Electric										18,647	39,548	34,350
Operating revenues	$ 73,438	$ 98,701	$ 94,753	$ 82,392	$ 81,233	$ 107,245	$ 95,548	$ 75,352		349,284	359,378	329,608
GSWC | Water:
Disaggregation of Revenue [Line Items]
Revenue from contract with customers										335,506	311,572	303,593
Operating revenues										330,637	319,830	295,258
GSWC | Water: | Tariff-based revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customers										329,670	305,244	298,818
GSWC | Water: | CPUC-approved surcharges (cost-recovery activities)
Disaggregation of Revenue [Line Items]
Revenue from contract with customers										3,736	4,322	2,962
GSWC | Water: | Other
Disaggregation of Revenue [Line Items]
Revenue from contract with customers										2,100	2,006	1,813
GSWC | Water: | Alternative revenue program
Disaggregation of Revenue [Line Items]
Regulated Operating Revenue										$ (4,869)	(8,258)	(8,335)
GSWC | Electric:
Disaggregation of Revenue [Line Items]
Revenue from contract with customers											37,038
Electric									$ 21,510		2,510
Operating revenues											39,548	34,350
GSWC | Electric: | Tariff-based revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customers											36,628
GSWC | Electric: | CPUC-approved surcharges (cost-recovery activities)
Disaggregation of Revenue [Line Items]
Revenue from contract with customers											410
American States Utility Services [Member] | Contracted services:
Disaggregation of Revenue [Line Items]
Period of Fixed Price Contracts to Operate and Maintain Water Systems at Various Military Bases										50 years
Revenue from contract with customers										$ 120,582	114,491	107,208
Operating revenues										$ 120,582	114,491	107,208
Number of construction performance obligation | unit										1
American States Utility Services [Member] | Contracted services: | Water
Disaggregation of Revenue [Line Items]
Revenue from contract with customers										$ 74,898	59,868	62,273
American States Utility Services [Member] | Contracted services: | Wastewater
Disaggregation of Revenue [Line Items]
Revenue from contract with customers										45,684	$ 54,623	44,935
Golden State Water Company and Bear Valley Electric Service, Inc. [Member] | Electric:
Disaggregation of Revenue [Line Items]
Revenue from contract with customers										35,969		34,715
Electric										1,055		365
Operating revenues										37,024		34,350
Golden State Water Company and Bear Valley Electric Service, Inc. [Member] | Electric: | Tariff-based revenues
Disaggregation of Revenue [Line Items]
Revenue from contract with customers										35,283		34,501
Golden State Water Company and Bear Valley Electric Service, Inc. [Member] | Electric: | CPUC-approved surcharges (cost-recovery activities)
Disaggregation of Revenue [Line Items]
Revenue from contract with customers										$ 686		$ 214

Revenues Contract assets and Co

Revenues Contract assets and Contract Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Contract with Customer, Asset and Liability [Line Items]
Contract with Customer, Liability, Revenue Recognized	$ 10,900
Revenue, Remaining Performance Obligation, Amount	3,200,000
American States Utility Services [Member]
Contract with Customer, Asset and Liability [Line Items]
Unbilled Contracts Receivable	14,924	$ 10,467
Government Contract Receivable	74,670	64,819
Contract assets	10,257	15,631
Contract liabilities	$ 1,800	$ 11,167
Minimum | American States Utility Services [Member]
Contract with Customer, Asset and Liability [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	34 years
Maximum | American States Utility Services [Member]
Contract with Customer, Asset and Liability [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	48 years
Contracted services: | American States Utility Services [Member]
Contract with Customer, Asset and Liability [Line Items]
Period of Fixed Price Contracts to Operate and Maintain Water Systems at Various Military Bases	50 years
Revenue, Performance Obligation, Description of Payment Terms	5

Regulatory Matters (Details)

Regulatory Matters (Details) - USD ($)	1 Months Ended		12 Months Ended
	Oct. 31, 2005	Jul. 31, 2005	Dec. 31, 2020	Dec. 31, 2019
Regulatory matters:
Total			$ 16,539,000	$ (2,450,000)
Regulatory Asset Not Accruing Carrying Costs			19,800,000
Regulatory Asset CEMA			4,400,000
Water Revenue Adjustment Mechanism [Member]
Regulatory matters:
Regulatory adjustment			5,900,000
Pension Costs and Other Postretirement Benefit Costs
Regulatory matters:
Regulatory Asset Not Accruing Carrying Costs			66,600,000
Flow-through taxes, net
Regulatory matters:
Total			(10,400,000)
Excess deferred income taxes
Regulatory matters:
Total			(78,300,000)
GSWC
Regulatory matters:
Total			12,373,000	(2,450,000)
Regulatory Asset CEMA			4,100,000
GSWC | Various refunds to customers
Regulatory matters:
Total			(4,577,000)	(8,478,000)
GSWC | WRAM, net of MCBA
Regulatory matters:
Total			13,741,000	22,535,000
GSWC | Water Revenue Adjustment Mechanism [Member]
Regulatory matters:
Total			(3,600,000)
Deferred Revenues			0
GSWC | Costs deferred for future recovery on Aerojet case
Regulatory matters:
Total			6,751,000	8,292,000
Regulatory Asset Recovery Periods		20 years
Increase in Revenue Requirement, Recoverable through Surcharges		$ 21,300,000
GSWC | Pension Costs and Other Postretirement Benefit Costs
Regulatory matters:
Regulatory Assets			66,600,000
Total			65,576,000	40,693,000
GSWC | Gain (Loss) on Derivative Instruments [Member]
Regulatory matters:
Total			0	3,171,000
GSWC | COVID-19 memorandum account
Regulatory matters:
Total			4,119,000	0
GSWC | Flow-through taxes, net
Regulatory matters:
Total			(9,722,000)	(12,439,000)
GSWC | Excess deferred income taxes
Regulatory matters:
Total			(74,185,000)	(79,886,000)
GSWC | Other Regulatory Assets
Regulatory matters:
Total			10,670,000	23,662,000
Bear Valley Electric Service, Inc.
Regulatory matters:
Regulatory Asset CEMA			295,000
Bear Valley Electric Service, Inc. | Gain (Loss) on Derivative Instruments [Member]
Regulatory matters:
Total			1,537,000	0
Bear Valley Electric Service, Inc. | Other Regulatory Assets
Regulatory matters:
Total			$ 2,629,000	$ 0
Maximum | GSWC | WRAM, net of MCBA
Regulatory matters:
Regulatory Asset Recovery Periods			24 months
Maximum | GSWC | Costs deferred for future recovery on Aerojet case
Regulatory matters:
Regulatory Asset Recovery Periods	20 years

Regulatory Matters 2 (Details)

Regulatory Matters 2 (Details) - USD ($)	1 Months Ended		12 Months Ended
	Oct. 31, 2005	Jul. 31, 2005	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Regulatory matters:
Regulatory Asset Not Accruing Carrying Costs			$ 19,800,000
Under (over) collection			(16,539,000)	$ 2,450,000
Water			330,637,000	319,830,000	$ 295,258,000
Excess deferred income taxes
Regulatory matters:
Under (over) collection			78,300,000
Flow-through taxes, net
Regulatory matters:
Under (over) collection			10,400,000
WRAM
Regulatory matters:
Regulatory adjustment			5,900,000
Pension Costs and Other Postretirement Benefit Costs
Regulatory matters:
Regulatory Asset Not Accruing Carrying Costs			66,600,000
GSWC
Regulatory matters:
Under (over) collection			(12,373,000)	2,450,000
Water			330,637,000	319,830,000	$ 295,258,000
GSWC | Excess deferred income taxes
Regulatory matters:
Under (over) collection			74,185,000	79,886,000
GSWC | Costs deferred for future recovery on Aerojet case
Regulatory matters:
Under (over) collection			(6,751,000)	(8,292,000)
Recovery period		20 years
Increase in Revenue Requirement, Recoverable through Surcharges		$ 21,300,000
Deferred Costs, Noncurrent			17,500,000
GSWC | Costs deferred for future recovery on Aerojet case | Maximum
Regulatory matters:
Recovery period	20 years
GSWC | Gain (Loss) on Derivative Instruments [Member]
Regulatory matters:
Under (over) collection			0	(3,171,000)
GSWC | Flow-through taxes, net
Regulatory matters:
Under (over) collection			$ 9,722,000	12,439,000
GSWC | WRAM, net of MCBA
Regulatory matters:
Commercial paper, term			90 days
Amount billed to customers as surcharges			$ 14,700,000
Under (over) collection			$ (13,741,000)	(22,535,000)
GSWC | WRAM, net of MCBA | Maximum
Regulatory matters:
Recovery period			24 months
GSWC | WRAM
Regulatory matters:
Under (over) collection			$ 3,600,000
Deferred Revenues			0
GSWC | Modified Cost Balancing Account
Regulatory matters:
Under (over) collection			(17,300,000)
GSWC | Pension Costs and Other Postretirement Benefit Costs
Regulatory matters:
Under (over) collection			(65,576,000)	(40,693,000)
Regulatory Assets			66,600,000
Various refunds to customers | GSWC
Regulatory matters:
Under (over) collection			$ 4,577,000	$ 8,478,000

Regulatory Matters 3 (Details)

Regulatory Matters 3 (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Regulatory matters:
Under (over) collection	$ 16,539	$ (2,450)
Other Liabilities, Current	10,437	10,341
GSWC
Regulatory matters:
Under (over) collection	12,373	(2,450)
Other Liabilities, Current	9,403	9,745
Other Regulatory Assets | GSWC
Regulatory matters:
Under (over) collection	10,670	23,662
Other Regulatory Assets | Bear Valley Electric Service, Inc.
Regulatory matters:
Under (over) collection	2,629	0
Pension Costs and Other Postretirement Benefit Costs | GSWC
Regulatory matters:
Regulatory asset authorized under settlement	66,600
Under (over) collection	65,576	$ 40,693
Under Collection in Two Way Pension Balancing Account [Member] | Pension Costs and Other Postretirement Benefit Costs | Bear Valley Electric Service, Inc.
Regulatory matters:
Under (over) collection	(206)
Under Collection in Two Way Pension Balancing Account [Member] | Pension Costs and Other Postretirement Benefit Costs | Golden State Water Company and Bear Valley Electric Service, Inc. [Member]
Regulatory matters:
Under (over) collection	$ (1,000)

Regulatory Matters 4 (Details)

Regulatory Matters 4 (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Oct. 31, 2005	Jul. 31, 2005	Dec. 31, 2020
GSWC | Costs deferred for future recovery on Aerojet case
Regulatory matters:
Increase in Revenue Requirement, Recoverable through Surcharges		$ 21.3
Recovery period		20 years
Reimbursement to recover costs			$ 17.5
GSWC | Costs deferred for future recovery on Aerojet case | Maximum
Regulatory matters:
Recovery period	20 years
GSWC | Water Revenue Adjustment Mechanism Net of Modified Cost Balancing Account [Member] | Maximum
Regulatory matters:
Recovery period			24 months
Bear Valley Electric Service, Inc. | Renewables Portfolio Standard [Member]
Regulatory matters:
Derivative, Term of Contract			ten

Regulatory Matters 5 (Details)

Regulatory Matters 5 (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Regulatory matters:
Total	$ 16,539	$ (2,450)
GSWC
Regulatory matters:
Total	12,373	(2,450)
GSWC | Pension Costs and Other Postretirement Benefit Costs
Regulatory matters:
Regulatory Assets	66,600
Total	$ 65,576	$ 40,693

Regulatory Matters 6 (Details)

Regulatory Matters 6 (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)unit	Dec. 31, 2019USD ($)
Regulatory matters:
Net regulatory assets	$ 16,539	$ (2,450)
Bear Valley Electric Service, Inc.
Regulatory matters:
Number of renewable energy credits that would be purchased | unit	578,000
Bear Valley Electric Service, Inc. | Renewables Portfolio Standard [Member]
Regulatory matters:
Derivative, Term of Contract	ten
GSWC
Regulatory matters:
Net regulatory assets	$ 12,373	(2,450)
Various refunds to customers | GSWC
Regulatory matters:
Net regulatory assets	$ (4,577)	$ (8,478)

Utility Plant and Intangible _3

Utility Plant and Intangible Assets (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Utility plant utilized in continuing operations by major asset class
Total amortized intangible assets		$ 30,321	$ 29,989
Total utility plant, at cost		1,930,224	1,839,421
Less - accumulated depreciation		(568,326)	(543,263)
Construction work in progress		(150,145)	(119,547)
Net utility plant		1,512,043	1,415,705	$ 1,296,310
American States Utility Services [Member] | Intangible Assets [Member]
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		571	571
Water Service Utility Operations [Member]
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		1,817,717	1,730,996
Water Service Utility Operations [Member] | Land
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		18,234	18,066
Water Service Utility Operations [Member] | Intangible Assets [Member]
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		28,906	28,578
Water Service Utility Operations [Member] | Source of water supply
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		92,166	91,685
Water Service Utility Operations [Member] | Pumping
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		190,901	178,058
Water Service Utility Operations [Member] | Water treatment
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		81,272	78,048
Water Service Utility Operations [Member] | Transmission and distribution
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		1,277,361	1,219,285
Water Service Utility Operations [Member] | General
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		128,877	117,276
Electric:
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		112,507	108,425
Electric: | Intangible Assets [Member]
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		1,200	1,200
Electric: | Transmission and distribution
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		87,461	84,018
Electric: | Generation
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		12,583	12,583
Electric: | General
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost	[1]	12,463	11,824
GSWC
Utility plant utilized in continuing operations by major asset class
Total amortized intangible assets		28,508	29,418
Total utility plant, at cost		1,784,402	1,808,867
Less - accumulated depreciation		(502,283)	(531,801)
Construction work in progress		(118,370)	(117,676)
Net utility plant		1,400,489	1,394,742
GSWC | Water Service Utility Operations [Member]
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		1,784,402	1,700,442
Net utility plant		1,400,489	1,322,062	1,218,468
GSWC | Water Service Utility Operations [Member] | Land
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		18,234	18,066
GSWC | Water Service Utility Operations [Member] | Intangible Assets [Member]
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		28,906	28,578
GSWC | Water Service Utility Operations [Member] | Source of water supply
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		92,166	91,685
GSWC | Water Service Utility Operations [Member] | Pumping
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		190,901	178,058
GSWC | Water Service Utility Operations [Member] | Water treatment
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		81,272	78,048
GSWC | Water Service Utility Operations [Member] | Transmission and distribution
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		1,277,361	1,219,285
GSWC | Water Service Utility Operations [Member] | General
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		95,562	86,722
GSWC | Electric:
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		0	108,425
Net utility plant			72,680	$ 62,624
GSWC | Electric: | Transmission and distribution
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		0	84,018
GSWC | Electric: | Generation
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost		0	12,583
GSWC | Electric: | General
Utility plant utilized in continuing operations by major asset class
Total utility plant, at cost	[1]	0	11,824
Conservation [Member]
Utility plant utilized in continuing operations by major asset class
Total amortized intangible assets		9,486	9,486
Conservation [Member] | GSWC
Utility plant utilized in continuing operations by major asset class
Total amortized intangible assets		$ 9,486	$ 9,486
[1]	Includes intangible assets of $1.2 million for the years ended December 31, 2020 and 2019 for studies performed in association with the electric segment.

Utility Plant and Intangible _4

Utility Plant and Intangible Assets 2 (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Intangible assets
Total utility plant, at cost		$ 1,930,224	$ 1,839,421
Total amortized intangible assets		30,321	29,989
Less - accumulated amortization		(24,460)	(24,309)
Intangible assets, net of amortization		5,861	5,680
Unamortized intangible assets	[1]	399	402
Amortization of intangible assets		654	$ 1,300	$ 1,100
Estimated future consolidated amortization expenses related to intangible assets
2014		142
2015		114
2016		114
2017		74
2018		0
Total		$ 444
Conservation [Member]
Intangible assets
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		3 years	3 years
Total amortized intangible assets		$ 9,486	$ 9,486
Water and water service rights
Intangible assets
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		30 years	30 years
Total amortized intangible assets	[2]	$ 8,694	$ 8,695
Water planning studies
Intangible assets
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		14 years	14 years
Total amortized intangible assets		$ 12,141	$ 11,808
GSWC
Intangible assets
Total utility plant, at cost		1,784,402	1,808,867
Total amortized intangible assets		28,508	29,418
Less - accumulated amortization		(24,305)	(24,166)
Intangible assets, net of amortization		4,203	5,252
Unamortized intangible assets	[1]	$ 399	$ 402
GSWC | Conservation [Member]
Intangible assets
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		3 years	3 years
Total amortized intangible assets		$ 9,486	$ 9,486
GSWC | Water and water service rights
Intangible assets
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		30 years	30 years
Total amortized intangible assets	[2]	$ 8,124	$ 8,124
GSWC | Water planning studies
Intangible assets
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		14 years	14 years
Total amortized intangible assets		$ 10,898	$ 11,808
Intangible Assets [Member] | American States Utility Services [Member]
Intangible assets
Total utility plant, at cost		$ 571	$ 571
[1]	The intangible assets not subject to amortization primarily consist of organization and consent fees.
[2]	Includes intangible assets of $571,000 for contracted services included in "Other Property and Investments" on the consolidated balance sheets as of December 31, 2020 and 2019.

Utility Plant and Intangible _5

Utility Plant and Intangible Assets 3 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of the beginning and ending aggregate carrying amount of the asset retirement obligations
Obligation at the beginning of the period	$ 8,863	$ 5,228
Additional liabilities incurred	165	271
Liabilities settled	(58)	(173)
Accretion	350	86
Asset Retirement Obligation, Revision of Estimate		3,451
Obligation at the end of the period	$ 9,320	$ 8,863
Wells and Related Equipment and Facilities [Member]
Intangible assets
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	50 years

Derivative Instruments (Details

Derivative Instruments (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)MWh	Dec. 31, 2019USD ($)
GSWC | Purchase power contract
Changes in the fair value of the derivative
Balance, at beginning of the period	$ 3,171	$ 311
Unrealized (loss) gain on purchased power contracts		(2,860)
Balance, at end of the period		$ 3,171
Bear Valley Electric Service, Inc.
Derivative instruments
Derivative Activity Volume | MWh	487,000
Changes in the fair value of the derivative
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	$ (1,500)
Bear Valley Electric Service, Inc. | Purchase power contract
Changes in the fair value of the derivative
Unrealized (loss) gain on purchased power contracts	1,634
Balance, at end of the period	$ (1,537)
Minimum | Bear Valley Electric Service, Inc.
Derivative instruments
Derivative, Term of Contract	3 years
Minimum | Bear Valley Electric Service, Inc. | Purchase power contract
Derivative instruments
Derivative, Term of Contract	3 years
Maximum | Bear Valley Electric Service, Inc.
Derivative instruments
Derivative, Term of Contract	5 years
Maximum | Bear Valley Electric Service, Inc. | Purchase power contract
Derivative instruments
Derivative, Term of Contract	5 years

Military Privatization (Details

Military Privatization (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Receivables from the U.S. government:
Less: allowance for doubtful accounts	$ (5,316)				$ (916)				$ (5,316)	$ (916)	$ (951)	$ (1,041)
Pretax income
Increase in pretax operating income	$ 29,277	$ 39,807	$ 35,716	$ 25,699	$ 24,724	$ 42,724	$ 39,430	$ 20,195	$ 130,499	127,073	100,983
Contracted services:
Military Privatization
Period of fixed price contracts to maintain water systems at various military bases									50 years
Number of Operating Segments									7
American States Utility Services [Member] | Contracted services:
Pretax income
Increase in pretax operating income									$ 22,309	$ 21,990	$ 20,414

Earnings Per Share and Capita_3

Earnings Per Share and Capital Stock (Details) - USD ($)		3 Months Ended								12 Months Ended
		Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Basic
Net Income		$ 20,211,000	$ 26,530,000	$ 25,612,000	$ 14,072,000	$ 16,700,000	$ 28,006,000	$ 26,784,000	$ 12,852,000	$ 86,425,000	$ 84,342,000	$ 63,871,000
Less: Distributed earnings to common shareholders										47,206,000	42,702,000	38,937,000
Less: Distributed earnings to participating securities										158,000	180,000	204,000
Undistributed earnings										39,061,000	41,460,000	24,730,000
Undistributed earnings allocated to common shareholders										38,930,000	41,285,000	24,601,000
Undistributed earnings allocated to participating securities											175,000	129,000
Total income available to common shareholders, basic										$ 86,136,000	$ 83,987,000	$ 63,538,000
Weighted average Common Shares outstanding, basic										36,880,000	36,814,000	36,733,000
Basic earnings per Common Share:
Earnings Per Share, Basic		$ 0.55	$ 0.72	$ 0.69	$ 0.38	$ 0.45	$ 0.76	$ 0.72	$ 0.35	$ 2.34	$ 2.28	$ 1.73
Diluted
Total income available to common shareholders, basic										$ 86,136,000	$ 83,987,000	$ 63,538,000
Undistributed earnings for dilutive stock options										131,000	175,000	129,000
Total common shareholders earnings, diluted										$ 86,267,000	$ 84,162,000	$ 63,667,000
Weighted average Common Shares outstanding, basic										36,880,000	36,814,000	36,733,000
Stock-based compensation (in shares)	[1]									115,000	150,000	203,000
Weighted average common shares outstanding, diluted										36,995,000	36,964,000	36,936,000
Diluted earnings per Common Share:
Earnings Per Share, Diluted		$ 0.54	$ 0.72	$ 0.69	$ 0.38	$ 0.45	$ 0.76	$ 0.72	$ 0.35	$ 2.33	$ 2.28	$ 1.72
Share based compensation arrangement
Proceeds from Stock Options Exercised, Distributed to Subsidiaries										$ 0	$ 0	$ 0
Dividend Reinvestment Plan Common Stock Capital Shares Reserved for Future Issuance		1,055,948								1,055,948
Common Shares authorized for issuance but unissued under 401(k) Plan		387,300								387,300
Restricted Stock Units
Share based compensation arrangement
Restricted stock units outstanding (in shares)		127,298								127,298
[1]	(1) In applying the treasury stock method of reflecting the dilutive effect of outstanding stock-based compensation in the calculation of diluted EPS, 127,298 restricted stock units, including performance awards, at December 31, 2020 were deemed to be outstanding in accordance with accounting guidance on earnings per share.

Earnings Per Share and Capita_4

Earnings Per Share and Capital Stock 2 (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Capital stock
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic		$ (175,000)	$ (129,000)
Additional disclosure
Dividend Reinvestment Plan Common Stock Capital Shares Reserved for Future Issuance	1,055,948
Common Shares authorized for issuance but unissued under 401(k) Plan	387,300
Common Shares issued as a result of the exercise of stock options	1,800	30,998	32,142
Cash proceeds from the exercise of stock options	$ 30,000	$ 519,000	$ 546,000
Proceeds from Stock Options Exercised, Distributed to Subsidiaries	0	0	0
Exercise of stock options and other issuance of Common Shares	$ 30,000	$ 519,000	$ 546,000
2000 and 2008 Employee Plans
Additional disclosure
Exercise of stock options and other issuance of Common Shares	42,489	88,772	44,906
AWR
Additional disclosure
Cash proceeds from the exercise of stock options	$ 30,000	$ 519,000	$ 546,000
GSWC
Additional disclosure
Exercise of stock options and other issuance of Common Shares	$ 60,000,000		$ 47,500,000
Common Stock [Member]
Additional disclosure
Exercise of stock options and other issuance of Common Shares	42,000	89,000	77,000
Exercise of stock options and other issuance of Common Shares	$ 30,000	$ 519,000	$ 546,000
Common Stock [Member] | GSWC
Additional disclosure
Exercise of stock options and other issuance of Common Shares	5	0	19
Exercise of stock options and other issuance of Common Shares	$ 60,000,000		$ 47,500,000

Dividend Limitations (Details)

Dividend Limitations (Details)	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Dividend limitations
Common shareholder’s equity ( Note 20)	$ 641,673,000	$ 601,530,000	$ 558,223,000	$ 529,945,000
Reinvested earnings in the business	385,007,000	345,964,000
AWR
Dividend limitations
Common shareholder’s equity ( Note 20)	641,673,000	601,530,000
Subsidiaries [Member]
Dividend limitations
Dividends paid	47,300,000	42,700,000	79,000,000
GSWC
Dividend limitations
Fixed amount in computing maximum ability to pay dividends	$ 21,000,000
Percentage of consolidated net income plus the aggregate net cash proceeds received from capital stock offerings or other instruments convertible into capital stock	100.00%
Amount available to pay dividends under the most restrictive of the Note Agreements	$ 576,400,000
Dividends paid	22,500,000	20,200,000	68,850,000
Common shareholder’s equity ( Note 20)	$ 583,298,000	551,188,000	503,575,000	474,374,000
Ratio of Indebtedness to Net Capital	0.4306
Reinvested earnings in the business	$ 228,392,000	257,434,000
GSWC | Maximum
Dividend limitations
Ratio of Indebtedness to Net Capital	0.6667
Earnings Reinvested in the Business
Dividend limitations
Common shareholder’s equity ( Note 20)	$ 385,007,000	345,964,000	304,534,000	279,821,000
Earnings Reinvested in the Business | GSWC
Dividend limitations
Common shareholder’s equity ( Note 20)	$ 228,392,000	$ 257,434,000	$ 211,163,000	$ 232,193,000

Bank Debt (Details)

Bank Debt (Details)	6 Months Ended	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Jul. 01, 2020USD ($)
Bank debt
Maximum borrowing capacity	$ 260,000,000	$ 260,000,000
Line of Credit Facility, Current Borrowing Capacity	200,000,000	200,000,000
Short-term borrowing activities (excluding letters of credit)
Notes Payable to Bank	$ 134,200,000	$ 134,200,000
Bear Valley Electric Service, Inc.
Bank debt
Maximum borrowing capacity				$ 35,000,000
Debt instrument, term	3 years	3 years
Incremental expansion of borrowing capacity	$ 15,000,000	$ 15,000,000		$ 35,000,000
Notes Payable	20,200,000	20,200,000
Long-term Debt [Member]
Bank debt
Notes Payable, Current	134,200,000	134,200,000	$ 205,000,000
Short-term borrowing activities (excluding letters of credit)
Notes Payable, Current	$ 134,200,000	134,200,000	$ 205,000,000
Short-term borrowing (excluding letters of credit)
Bank debt
Interest Rate at the end of the period (as a percent)			2.44%
Average Amount Outstanding		$ 162,995,000	$ 167,392,000
Weighted Average Annual Interest Rate (as a percent)	1.47%	1.47%	2.88%
Maximum Amount Outstanding		$ 249,200,000	$ 205,500,000
Short-term borrowing activities (excluding letters of credit)
Weighted Average Annual Interest Rate (as a percent)	1.47%	1.47%	2.88%
Average Amount Outstanding		$ 162,995,000	$ 167,392,000
Maximum Amount Outstanding		249,200,000	$ 205,500,000
Interest Rate at the end of the period (as a percent)			2.44%
Average amount outstanding		$ 162,995,000	$ 167,392,000
Short-term borrowing (excluding letters of credit) | Minimum
Bank debt
Interest Rate at the end of the period (as a percent)	1.19%	1.19%
Short-term borrowing activities (excluding letters of credit)
Interest Rate at the end of the period (as a percent)	1.19%	1.19%
Short-term borrowing (excluding letters of credit) | Maximum
Bank debt
Interest Rate at the end of the period (as a percent)	1.90%	1.90%
Short-term borrowing activities (excluding letters of credit)
Interest Rate at the end of the period (as a percent)	1.90%	1.90%
Syndicated revolving credit facility
Bank debt
Variable rate basis		Euro rate
Syndicated revolving credit facility | Bear Valley Electric Service, Inc.
Bank debt
Interest coverage ratio		35.6
Total funded debt ratio		0.24
Short-term borrowing activities (excluding letters of credit)
Interest coverage ratio		35.6
Total funded debt ratio		0.24
Syndicated revolving credit facility | Minimum
Bank debt
Interest coverage ratio		3.25
Short-term borrowing activities (excluding letters of credit)
Interest coverage ratio		3.25
Syndicated revolving credit facility | Maximum
Bank debt
Total funded debt ratio		0.65
Short-term borrowing activities (excluding letters of credit)
Total funded debt ratio		0.65
AWR
Bank debt
Line of Credit Facility, Current Borrowing Capacity	$ 200,000,000	$ 200,000,000
AWR | Long-term Debt [Member]
Bank debt
Notes Payable, Current	114,000,000	114,000,000	205,000,000
Short-term borrowing activities (excluding letters of credit)
Notes Payable, Current	$ 114,000,000	$ 114,000,000	$ 205,000,000
AWR | Short-term borrowing (excluding letters of credit)
Bank debt
Interest Rate at the end of the period (as a percent)	1.19%	1.19%	2.44%
Average Amount Outstanding		$ 160,495,000	$ 167,392,000
Weighted Average Annual Interest Rate (as a percent)	1.47%	1.47%	2.88%
Maximum Amount Outstanding		$ 249,000,000	$ 205,500,000
Short-term borrowing activities (excluding letters of credit)
Weighted Average Annual Interest Rate (as a percent)	1.47%	1.47%	2.88%
Average Amount Outstanding		$ 160,495,000	$ 167,392,000
Maximum Amount Outstanding		$ 249,000,000	$ 205,500,000
Interest Rate at the end of the period (as a percent)	1.19%	1.19%	2.44%
Average amount outstanding		$ 160,495,000	$ 167,392,000
AWR | Syndicated revolving credit facility
Bank debt
Interest coverage ratio		7.74
Total funded debt ratio		0.47
Short-term borrowing activities (excluding letters of credit)
Interest coverage ratio		7.74
Total funded debt ratio		0.47
AWR | Syndicated revolving credit facility | Bear Valley Electric Service, Inc.
Bank debt
Total funded debt ratio		0.65
Short-term borrowing activities (excluding letters of credit)
Total funded debt ratio		0.65
AWR | Syndicated revolving credit facility | Minimum
Bank debt
Interest coverage ratio		3.25
Total funded debt ratio		0.65
Short-term borrowing activities (excluding letters of credit)
Interest coverage ratio		3.25
Total funded debt ratio		0.65
AWR | Syndicated revolving credit facility | Maximum
Bank debt
Total funded debt ratio		1
Short-term borrowing activities (excluding letters of credit)
Total funded debt ratio		1
AWR | Syndicated revolving credit facility | Letters of credit
Bank debt
Maximum borrowing capacity	$ 25,000,000	$ 25,000,000
Letter of credit, amount	$ 455,000	$ 455,000
Letter of credit fee (as a percent)		0.65%

Long-Term Debt (Details)

Long-Term Debt (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Jul. 08, 2020	Dec. 31, 2019	Dec. 31, 2014	Dec. 31, 2013
GSWC
Debt Instrument [Line Items]
Ratio of Indebtedness to Net Capital	0.4306
Ratio of Indebtedness to EBITDA	3.1
GSWC | Maximum
Debt Instrument [Line Items]
Ratio of Indebtedness to Net Capital	0.6667
Ratio of Indebtedness to EBITDA	8
Private Placement Notes [Member] | GSWC
Debt Instrument [Line Items]
Interest coverage ratio	4
Private Placement Notes [Member] | GSWC | Minimum
Debt Instrument [Line Items]
Interest coverage ratio	2
9.56% notes due 2031
Debt Instrument [Line Items]
Interest rate (as a percent)	9.56%		9.56%
9.56% notes due 2031 | GSWC
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 28,000,000
Interest rate (as a percent)	9.56%		9.56%
Debt Instrument Redemption Premium above Treasury Yield	55.00%
9.56% notes due 2031 | GSWC | Maximum
Debt Instrument [Line Items]
Redemption premium after 2021 (as a percent)	3.00%
5.87% notes due 2028
Debt Instrument [Line Items]
Interest rate (as a percent)	5.87%		5.87%
5.87% notes due 2028 | GSWC
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 40,000,000
Interest rate (as a percent)	5.87%		5.87%
American Recovery and Reinvestment Act Obligation due 2033 | GSWC
Debt Instrument [Line Items]
Interest rate (as a percent)					2.50%
3.45% notes due 2029
Debt Instrument [Line Items]
Interest rate (as a percent)	3.45%		3.45%
3.45% notes due 2029 | GSWC
Debt Instrument [Line Items]
Debt Instrument, Face Amount				$ 15,000,000
Interest rate (as a percent)	3.45%		3.45%
Private Placement Notes [Member] | GSWC
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 160,000,000
Debt Instrument Redemption Premium above Treasury Yield	50.00%
2.17% notes due 2030
Debt Instrument [Line Items]
Interest rate (as a percent)	2.17%
2.17% notes due 2030 | GSWC
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 85,000,000
Interest rate (as a percent)	2.17%	2.17%
2.90% notes due 2040
Debt Instrument [Line Items]
Interest rate (as a percent)	2.90%
2.90% notes due 2040 | GSWC
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 75,000,000
Interest rate (as a percent)	2.90%	2.90%

Long-Term Debt 2 (Details)

Long-Term Debt 2 (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Annual maturities of all long-term debt, including capitalized leases
Total	$ 444,271	$ 284,699
GSWC
Annual maturities of all long-term debt, including capitalized leases
2021	358
2022	382
2023	406
2024	430
2025	449
Thereafter	442,246
Total	$ 444,271	$ 284,699

Long-Term Debt 3 (Details)

Long-Term Debt 3 (Details)	3 Months Ended	12 Months Ended
	Dec. 31, 2009USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2013	Dec. 31, 2014USD ($)	Oct. 31, 2009USD ($)
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 260,000,000
Loan proceeds received for reimbursement of costs of conversion		$ 159,413,000	$ 0	$ 0
3.45% notes due 2029
Debt Instrument [Line Items]
Interest rate (as a percent)		3.45%	3.45%
GSWC
Debt Instrument [Line Items]
Ratio of Indebtedness to EBITDA		3.1
Loan proceeds received for reimbursement of costs of conversion		$ 159,413,000	$ 0	$ 0
GSWC | Maximum
Debt Instrument [Line Items]
Ratio of Indebtedness to EBITDA		8
GSWC | Private Placement Notes [Member]
Debt Instrument [Line Items]
Debt Instrument Covenant Interest Coverage Ratio		4
GSWC | Private Placement Notes [Member] | Minimum
Debt Instrument [Line Items]
Debt Instrument Covenant Interest Coverage Ratio		2
GSWC | 3.45% notes due 2029
Debt Instrument [Line Items]
Debt Instrument, Face Amount						$ 15,000,000
Interest rate (as a percent)		3.45%	3.45%
GSWC | American Recovery and Reinvestment Act Obligation due 2033
Debt Instrument [Line Items]
Maximum borrowing capacity							$ 9,000,000
Interest rate (as a percent)					2.50%
Maturity term					20 years
Loan proceeds received for reimbursement of costs of conversion	$ 8,600,000

Taxes on Income (Details)

Taxes on Income (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Taxes on income
Unrecognized Tax Benefits	$ 0	$ 0	$ 0
Deferred tax assets:
Regulatory-liability-related	32,640,000	33,080,000
Contributions and advances	6,390,000	5,777,000
Deferred Tax Assets, Other	6,092,000	5,792,000
Deferred tax assets	45,122,000	44,649,000
Deferred tax liabilities:
Fixed assets	(146,688,000)	(144,444,000)
Regulatory-asset-related: depreciation and other	(22,205,000)	(20,641,000)
Balancing and memorandum accounts (non-flow-through)	(7,401,000)	(4,868,000)
Deferred tax liabilities	(176,294,000)	(169,953,000)
Accumulated deferred income taxes - net	(131,172,000)	(125,304,000)
Current
Federal	19,240,000	12,507,000	17,252,000
State	6,714,000	5,540,000	6,538,000
Total current tax expense	25,954,000	18,047,000	23,790,000
Deferred
Federal	1,814,000	6,407,000	(4,334,000)
State	429,000	216,000	(1,439,000)
Total deferred tax (benefit) expense	2,243,000	6,623,000	(5,773,000)
Reconciliations of the effective tax rates to the federal statutory rate
Federal taxes on pretax income at statutory rate (21% in 2018; 35% in 2017 and 2016)	24,071,000	22,872,000	17,196,000
Increase (decrease) in taxes resulting from:	5,764,000	4,758,000	3,693,000
Excess deferred tax amortization	(1,550,000)	(1,579,000)	(2,101,000)
Flow-through on fixed assets	1,056,000	1,244,000	429,000
Flow-through on removal costs	(1,031,000)	(1,582,000)	(1,445,000)
Investment tax credit	(71,000)	(71,000)	(69,000)
Other- net	(42,000)	(972,000)	314,000
Total income tax expense operations	28,197,000	24,670,000	18,017,000
Income before income tax expense	$ 114,622,000	$ 109,012,000	$ 81,888,000
Effective income tax rate (as a percent)	24.60%	22.60%	22.00%
GSWC
Deferred tax assets:
Regulatory-liability-related	$ 30,782,000	$ 33,080,000
Contributions and advances	6,771,000	6,158,000
Deferred Tax Assets, Other	6,663,000	6,618,000
Deferred tax assets	44,216,000	45,856,000
Deferred tax liabilities:
Fixed assets	(141,422,000)	(147,759,000)
Regulatory-asset-related: depreciation and other	(21,060,000)	(20,641,000)
Balancing and memorandum accounts (non-flow-through)	(6,315,000)	(5,262,000)
Deferred tax liabilities	(168,797,000)	(173,662,000)
Accumulated deferred income taxes - net	(124,581,000)	(127,806,000)
Current
Federal	14,674,000	9,616,000	$ 14,488,000
State	5,849,000	5,480,000	5,932,000
Total current tax expense	20,523,000	15,096,000	20,420,000
Deferred
Federal	949,000	4,924,000	(5,531,000)
State	232,000	157,000	(1,286,000)
Total deferred tax (benefit) expense	1,181,000	5,081,000	(6,817,000)
Reconciliations of the effective tax rates to the federal statutory rate
Federal taxes on pretax income at statutory rate (21% in 2018; 35% in 2017 and 2016)	18,202,000	18,236,000	12,939,000
Increase (decrease) in taxes resulting from:	4,920,000	4,656,000	3,335,000
Excess deferred tax amortization	(1,477,000)	(1,579,000)	(2,101,000)
Flow-through on fixed assets	1,042,000	1,244,000	429,000
Flow-through on removal costs	(1,026,000)	(1,582,000)	(1,445,000)
Investment tax credit	(71,000)	(71,000)	(69,000)
Other- net	114,000	(727,000)	515,000
Total income tax expense operations	21,704,000	20,177,000	13,603,000
Income before income tax expense	86,675,000	86,840,000	61,615,000
Pretax income from operations	$ 86,675,000	$ 86,840,000	$ 61,615,000
Effective income tax rate (as a percent)	25.00%	23.20%	22.10%

Employee Benefit Plans 1 (Detai

Employee Benefit Plans 1 (Details) - Pension Benefits	12 Months Ended
	Dec. 31, 2020participantitem
Employee benefit plans
Minimum age for eligibility under the Pension Plan | item	21
Minimum period of service for eligibility under the Pension Plan	5 years
Normal retirement benefit (as a percent)	2.00%
Defined benefit plan number of highest consecutive years average earnings used in computing retirement benefit	5 years
Maximum number of years of credited service considered in determining retirement benefit	40 years
Number of participants in the Pension Plan | participant	935
Eligibility for employer matching contributions, period of service	3 years
Minimum
Employee benefit plans
Percentage of participant's eligible pay contributed to the plan by the employer	3.00%
Maximum
Employee benefit plans
Percentage of participant's eligible pay contributed to the plan by the employer	5.25%

Employee Benefit Plans 2 (Detai

Employee Benefit Plans 2 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits
Change in Projected Benefit Obligation:
Projected benefit obligation at beginning of year	$ 231,852	$ 196,082
Service cost	5,558	4,441	$ 5,342
Interest cost	7,880	8,527	7,646
Actuarial (gain) loss	35,453	29,784
Benefits/expenses paid	(7,957)	(6,982)
Projected benefit obligation at end of year	272,786	231,852	196,082
Changes in Plan Assets:
Fair value of plan assets at beginning of year	192,477	162,529
Actual return on plan assets	24,909	33,018
Employer contributions	3,718	3,913
Benefits/expenses paid	(7,957)	(6,983)
Fair value of plan assets at end of year	213,147	192,477	162,529
Funded Status:
Net amount recognized as accrued pension cost	(59,639)	(39,375)
Post-Retirement Medical Benefits
Change in Projected Benefit Obligation:
Projected benefit obligation at beginning of year	7,395	7,886
Service cost	171	186	218
Interest cost	208	285	292
Actuarial (gain) loss	(1,604)	(538)
Benefits/expenses paid	(264)	(424)
Projected benefit obligation at end of year	5,906	7,395	7,886
Changes in Plan Assets:
Fair value of plan assets at beginning of year	11,271	10,010
Actual return on plan assets	1,307	1,685
Employer contributions	269	170
Benefits/expenses paid	(534)	(594)
Fair value of plan assets at end of year	12,313	11,271	$ 10,010
Funded Status:
Net amount recognized as accrued pension cost	$ 6,407	$ 3,876

Employee Benefit Plans 3 (Detai

Employee Benefit Plans 3 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amounts recognized on the balance sheets:
Non-current liabilities				$ (95,639)	$ (68,469)
Pension Benefits
Amounts recognized on the balance sheets:
Non-current assets				0	0
Current liabilities				0	0
Non-current liabilities				(59,639)	(39,375)
Net amount recognized				(59,639)	(39,375)
Amounts recognized in regulatory assets consist of:
Prior service cost (credit)				2,757	3,191
Net (gain) loss				57,716	37,309
Regulatory assets (liabilities)	$ 60,473	$ 35,213	$ 35,213	60,473	40,500	$ 35,213
Unfunded accrued pension cost				(834)	(1,125)
Net liability (asset) recognized				59,639	39,375
Changes in plan assets and benefit obligations recognized in regulatory assets:
Regulatory asset at beginning of year	40,500	35,213
Net loss (gain)	(22,343)	(7,140)
New prior service cost	0	0
Amortization of prior service (cost) credit	(435)	(434)
Amortization of net gain (loss)	(1,935)	(1,419)
Total change in regulatory asset	19,973	5,287
Regulatory asset (liability) at end of year	60,473	40,500	35,213
Net periodic pension costs	4,010	4,447	3,070
Change in regulatory asset	19,973	5,287
Total recognized in net periodic pension cost and regulatory asset (liability)	23,983	9,734
Additional year-end information for plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation				272,786	231,852
Accumulated benefit obligation				253,108	215,996
Fair value of plan assets				$ 213,147	$ 192,477
Weighted-average assumptions used to determine benefit obligations at December 31:
Discount rate				2.55%	3.43%
Pension Benefits | Minimum
Weighted-average assumptions used to determine benefit obligations at December 31:
Rate of compensation increase				3.00%	3.00%	3.00%
Pension Benefits | Maximum
Weighted-average assumptions used to determine benefit obligations at December 31:
Rate of compensation increase				8.00%	8.00%	8.00%
Post-Retirement Medical Benefits
Amounts recognized on the balance sheets:
Non-current assets				$ 6,407	$ 3,876
Current liabilities				0	0
Non-current liabilities				0	0
Net amount recognized				6,407	3,876
Amounts recognized in regulatory assets consist of:
Prior service cost (credit)				0	0
Net (gain) loss				(6,855)	(5,432)
Regulatory assets (liabilities)	(5,432)	(5,432)	(4,459)	(6,855)	(5,432)	$ (4,459)
Unfunded accrued pension cost				448	1,556
Net liability (asset) recognized				(6,407)	(3,876)
Changes in plan assets and benefit obligations recognized in regulatory assets:
Regulatory asset at beginning of year	(5,432)	(4,459)
Net loss (gain)	2,400	1,775
New prior service cost	0	0
Amortization of prior service (cost) credit	0	0
Amortization of net gain (loss)	977	802
Total change in regulatory asset	(1,423)	(973)
Regulatory asset (liability) at end of year	(6,855)	(5,432)	(4,459)
Net periodic pension costs	(1,108)	(779)	$ (752)
Change in regulatory asset	(1,423)	(973)
Total recognized in net periodic pension cost and regulatory asset (liability)	$ (2,531)	$ (1,752)
Additional year-end information for plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation				5,906	7,395
Fair value of plan assets				$ 12,313	$ 11,271
Weighted-average assumptions used to determine benefit obligations at December 31:
Discount rate				2.20%	3.12%

Employee Benefit Plans 4 (Detai

Employee Benefit Plans 4 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Union plan
Weighted-average assumptions used to determine net periodic cost:
Expected long-term return on plan assets	6.00%	6.00%	6.00%
Non-union plan
Weighted-average assumptions used to determine net periodic cost:
Expected long-term return on plan assets	4.20%	4.20%	4.20%
Pension Benefits
Components of Net Periodic Benefits Cost:
Service cost	$ 5,558	$ 4,441	$ 5,342
Interest cost	7,880	8,527	7,646
Expected return on plan assets	(11,798)	(10,374)	(11,172)
Amortization of prior service cost (credit)	435	434	0
Amortization of actuarial (gain) loss	1,935	1,419	1,254
Net periodic pension cost under accounting standards	4,010	4,447	3,070
Regulatory adjustment	(483)	(593)	0
Total expense recognized, before surcharges and allocation to overhead pool	$ 3,527	$ 3,854	$ 3,070
Weighted-average assumptions used to determine net periodic cost:
Discount rate	3.43%	4.43%	3.76%
Expected long-term return on plan assets	6.25%	6.50%	6.50%
Pension Benefits | Minimum
Weighted-average assumptions used to determine net periodic cost:
Rate of compensation increase	3.00%	3.00%	3.00%
Pension Benefits | Maximum
Weighted-average assumptions used to determine net periodic cost:
Rate of compensation increase	8.00%	8.00%	8.00%
Post-Retirement Medical Benefits
Components of Net Periodic Benefits Cost:
Service cost	$ 171	$ 186	$ 218
Interest cost	208	285	292
Expected return on plan assets	(510)	(449)	(493)
Amortization of prior service cost (credit)		0	0
Amortization of actuarial (gain) loss	(977)	(801)	(769)
Net periodic pension cost under accounting standards	(1,108)	(779)	(752)
Regulatory adjustment	0	0	0
Total expense recognized, before surcharges and allocation to overhead pool	$ (1,108)	$ (779)	$ (752)
Weighted-average assumptions used to determine net periodic cost:
Discount rate	3.12%	4.20%	3.52%

Employee Benefit Plans 5 (Detai

Employee Benefit Plans 5 (Details) - Pension Benefits - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee benefit plans
Regulatory adjustment	$ 483	$ 593	$ 0
GSWC
Employee benefit plans
Regulatory adjustment	483	(593)	1,700
Bear Valley Electric Service, Inc.
Employee benefit plans
Regulatory adjustment	$ 200	$ 205	$ 271

Employee Benefit Plans 6 (Detai

Employee Benefit Plans 6 (Details)	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Employee benefit plans
Actual asset allocations	100.00%	100.00%
Target asset allocations	100.00%	100.00%
Pension Benefits | Equity securities
Employee benefit plans
Actual asset allocations	59.00%	56.00%
Target asset allocations	60.00%	60.00%
Pension Benefits | Debt securities
Employee benefit plans
Actual asset allocations	36.00%	39.00%
Target asset allocations	40.00%	40.00%
Pension Benefits | Real Estate Funds
Employee benefit plans
Actual asset allocations	5.00%	5.00%
Pension Benefits | Cash equivalents
Employee benefit plans
Actual asset allocations	0.00%	0.00%
Post-Retirement Medical Benefits
Employee benefit plans
Actual asset allocations	100.00%	100.00%
Target asset allocations	100.00%	100.00%
Post-Retirement Medical Benefits | Equity securities
Employee benefit plans
Actual asset allocations	63.00%	61.00%
Target asset allocations	60.00%	60.00%
Post-Retirement Medical Benefits | Debt securities
Employee benefit plans
Actual asset allocations	36.00%	38.00%
Target asset allocations	40.00%	40.00%
Post-Retirement Medical Benefits | Real Estate Funds
Employee benefit plans
Actual asset allocations	0.00%	0.00%
Post-Retirement Medical Benefits | Cash equivalents
Employee benefit plans
Actual asset allocations	1.00%	1.00%

Employee Benefit Plans 7 (Detai

Employee Benefit Plans 7 (Details) - Pension Benefits - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee benefit plans
Fair Value	$ 213,147	$ 192,477	$ 162,529
Unfunded Commitments	0	0
Cash equivalents
Employee benefit plans
Fair Value	589	600
Unfunded Commitments	0	0
Fixed income fund
Employee benefit plans
Fair Value	76,221	74,123
Unfunded Commitments	0	0
Total equity funds
Employee benefit plans
Fair Value	126,002	108,775
Unfunded Commitments	0
U.S. small/mid cap funds
Employee benefit plans
Fair Value	21,837	17,865
Unfunded Commitments	0	0
U.S. large cap funds
Employee benefit plans
Fair Value	53,677	47,132
Unfunded Commitments	0	0
International funds
Employee benefit plans
Fair Value	50,488	43,778
Unfunded Commitments	0	0
Real estate funds
Employee benefit plans
Fair Value	10,335	8,979
Unfunded Commitments	$ 0	$ 0

Employee Benefit Plans 8 (Detai

Employee Benefit Plans 8 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Post-Retirement Medical Benefits
Employee benefit plans
Employer contributions	$ 269	$ 170
Pension Benefits
Employee benefit plans
Employer contributions	3,718	$ 3,913
Expected future employer's contribution	$ 3,600
Minimum | Fixed income fund | Post-Retirement Medical Benefits
Employee benefit plans
Maturity period of investments	1 year
Maximum | Fixed income fund | Post-Retirement Medical Benefits
Employee benefit plans
Maturity period of investments	20 years

Employee Benefit Plans 9 (Detai

Employee Benefit Plans 9 (Details) - Post-Retirement Medical Benefits - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee benefit plans
Fair value of post-retirement plan assets	$ 12,313	$ 11,271	$ 10,010
Fair Value
Employee benefit plans
Fair value of post-retirement plan assets	12,312	11,271
Level 1
Employee benefit plans
Fair value of post-retirement plan assets	12,312	11,271
Level 2
Employee benefit plans
Fair value of post-retirement plan assets	0	0
Level 3
Employee benefit plans
Fair value of post-retirement plan assets	0	0
Cash equivalents | Fair Value
Employee benefit plans
Fair value of post-retirement plan assets	169	69
Cash equivalents | Level 1
Employee benefit plans
Fair value of post-retirement plan assets	169	69
Cash equivalents | Level 2
Employee benefit plans
Fair value of post-retirement plan assets	0	0
Cash equivalents | Level 3
Employee benefit plans
Fair value of post-retirement plan assets	0	0
Fixed income fund | Fair Value
Employee benefit plans
Fair value of post-retirement plan assets	4,436	4,279
Fixed income fund | Level 1
Employee benefit plans
Fair value of post-retirement plan assets	4,436	4,279
Fixed income fund | Level 2
Employee benefit plans
Fair value of post-retirement plan assets	0	0
Fixed income fund | Level 3
Employee benefit plans
Fair value of post-retirement plan assets	0	0
U.S. large cap funds | Fair Value
Employee benefit plans
Fair value of post-retirement plan assets	7,707	6,923
U.S. large cap funds | Level 1
Employee benefit plans
Fair value of post-retirement plan assets	7,707	$ 6,923
U.S. large cap funds | Level 2
Employee benefit plans
Fair value of post-retirement plan assets	0
U.S. large cap funds | Level 3
Employee benefit plans
Fair value of post-retirement plan assets	$ 0

Employee Benefit Plans 10 (Deta

Employee Benefit Plans 10 (Details) $ in Thousands	Dec. 31, 2020USD ($)
Pension Benefits
Employee benefit plans
2021	$ 8,572
2022	9,262
2023	9,880
2024	10,494
2025	11,142
Thereafter	63,680
Total	113,030
Post-Retirement Medical Benefits
Employee benefit plans
2021	486
2022	503
2023	516
2024	489
2025	476
Thereafter	1,813
Total	$ 4,283

Employee Benefit Plans 11 (Deta

Employee Benefit Plans 11 (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Healthcare Cost Trend Rate
Initial health care cost for employees under age of 65 (as a percent)	5.20%
Ultimate health care cost for employees under age of 65 (as a percent)	4.40%
Initial Health care cost for employees of age 65 and over (as a percent)	4.30%
Ultimate health care cost for employees of age 65 and over (as a percent)	4.00%
Union plan
Employee benefit plans
Expected long-term return on plan assets	6.00%	6.00%	6.00%
Non-union plan
Employee benefit plans
Expected long-term return on plan assets	4.20%	4.20%	4.20%

Employee Benefit Plans 12 (Deta

Employee Benefit Plans 12 (Details) - SERP - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Balance in Rabbi Trust
Balance in Rabbi Trust	$ 25,900
Fair value of assets held in Rabbi Trust	0	$ 0
Rabbi Trust | Fair Value
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	25,912	21,553
Level 1 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	25,912	21,553
Level 2 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	0	0
Level 3 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	0	0
Cash equivalents | Rabbi Trust | Fair Value
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	8	72
Cash equivalents | Level 1 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	8	72
Cash equivalents | Level 2 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	0	0
Cash equivalents | Level 3 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	0	0
Fixed income fund | Rabbi Trust | Fair Value
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	10,201	8,427
Fixed income fund | Level 1 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	10,201	8,427
Fixed income fund | Level 2 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	0	0
Fixed income fund | Level 3 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	0	0
Equity securities | Rabbi Trust | Fair Value
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	15,703	13,054
Equity securities | Level 1 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	15,703	13,054
Equity securities | Level 2 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	0	0
Equity securities | Level 3 | Rabbi Trust
Balance in Rabbi Trust
Fair value of assets held in Rabbi Trust	$ 0	$ 0

Employee Benefit Plans 13 (Deta

Employee Benefit Plans 13 (Details) - SERP - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in Benefit Obligation:
Projected benefit obligation at beginning of year	$ 29,703	$ 24,517
Service cost	1,029	1,193	$ 1,096
Interest cost	988	1,069	888
Actuarial (gain) loss	5,479	3,419
Benefits/expenses paid	(597)	(495)
Projected benefit obligation at end of year	36,602	29,703	$ 24,517
Changes in Plan Assets:
Fair value of plan assets at beginning of year	0
Fair value of plan assets at end of year	0	0
Funded Status:
Net amount recognized as accrued pension cost	$ (36,602)	$ (29,703)

Employee Benefit Plans 14 (Deta

Employee Benefit Plans 14 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amounts recognized on the balance sheets:
Non-current liabilities				$ (95,639)	$ (68,469)
SERP
Amounts recognized on the balance sheets:
Current liabilities				(602)	(609)
Non-current liabilities				(36,000)	(29,094)
Net amount recognized				(36,602)	(29,703)
Amounts recognized in regulatory assets consist of:
Prior service cost (credit)				0	0
Net loss				12,988	8,352
Regulatory assets (liabilities)	$ 12,988	$ 5,403	$ 5,403	12,988	8,352	$ 5,403
Unfunded accrued pension cost				23,614	21,351
Net liability (asset) recognized				36,602	29,703
Changes in plan assets and benefit obligations recognized in regulatory assets:
Regulatory asset at beginning of year	8,352	5,403
Net (gain) loss	5,479	3,419
Amortization of prior service (cost) credit	0	0
Amortization of net gain (loss)	(843)	(470)
Total change in regulatory asset	4,636	2,949
Regulatory asset (liability) at end of year	12,988	8,352	5,403
Net periodic pension costs	2,860	2,733	$ 3,033
Change in regulatory asset	4,636	2,949
Total recognized in net periodic pension cost and regulatory asset (liability)	$ 7,496	$ 5,682
Additional year-end information for plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation				36,602	29,703	$ 24,517
Accumulated benefit obligation				30,428	26,251
Fair value of plan assets				$ 0	$ 0
Weighted-average assumptions used to determine benefit obligations at December 31:
Discount rate				2.52%	3.36%
Rate of compensation increase				4.00%	4.00%

Employee Benefit Plans 15 (Deta

Employee Benefit Plans 15 (Details) - SERP - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components of Net Periodic Benefits Cost:
Service cost	$ 1,029	$ 1,193	$ 1,096
Interest cost	988	1,069	888
Amortization of prior service cost (credit)	0	0	0
Amortization of actuarial (gain) loss	843	471	1,049
Net periodic pension cost under accounting standards	$ 2,860	$ 2,733	$ 3,033
Weighted-average assumptions used to determine net periodic cost:
Discount rate	3.36%	4.40%	3.72%
Rate of compensation increase	4.00%	4.00%	4.00%

Employee Benefit Plans 16 (Deta

Employee Benefit Plans 16 (Details) - SERP $ in Thousands	Dec. 31, 2020USD ($)
Employee benefit plans
2021	$ 602
2022	792
2023	787
2024	1,039
2025	1,029
Thereafter	11,937
Total	$ 16,186

Employee Benefit Plans 17 (Deta

Employee Benefit Plans 17 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Employer's contribution	$ 2.7	$ 2.5	$ 2.4
Employer discretionary contribution amount	$ 1.9	$ 1.6	$ 1.3

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)stock_planshares	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Stock compensation plans
Number of stock incentive plans | stock_plan	3
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 122
Stock-based compensation recognized in the income statement, before taxes	$ 2,463	$ 2,517	$ 3,851
Immediate vesting for employees of certain age and above	55 years
GSWC
Stock compensation plans
Stock-based compensation recognized in the income statement, before taxes	$ 2,349	2,253	3,397
Capitalized equity-based compensation cost	299	265	199
Nonqualified stock options
Stock compensation plans
Tax benefits from exercise of stock-based awards	1,200	1,800	1,600
Nonqualified stock options | GSWC
Stock compensation plans
Tax benefits from exercise of stock-based awards	1,200	1,800	1,600
Restricted Stock Units | Employees and directors
Stock compensation plans
Stock-based compensation recognized in the income statement, before taxes	2,463	2,517	3,851
Restricted Stock Units | Employees and directors | GSWC
Stock compensation plans
Stock-based compensation recognized in the income statement, before taxes	$ 2,349	$ 2,253	$ 3,397
Performance awards
Stock compensation plans
Vesting period	3 years
2000 and 2008 Employee Plans | Nonqualified stock options
Stock compensation plans
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
Common stock entitled to be received under each award | shares	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
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%
2003 and 2013 Directors plans [Member]
Stock compensation plans
Vesting period	90 days
Maximum
Stock compensation plans
Chang in control, term	24
Weighted Average [Member]
Stock compensation plans
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 10 months 28 days
Weighted Average [Member] | Restricted Stock [Member]
Stock compensation plans
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 2 months 15 days

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans 2 (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Options
Common Shares issued as a result of the exercise of stock options	1,800	30,998	32,142
Additional disclosure
Cash proceeds from the exercise of stock options	$ 30	$ 519	$ 546
Unrecognized compensation cost	$ 122
Maximum
Additional disclosure
Percentage of target amount of performance shares	200.00%
Minimum
Additional disclosure
Percentage of target amount of performance shares	0.00%
Weighted Average [Member]
Additional disclosure
Expected recognition period for unrecognized compensation cost	1 year 10 months 28 days
Restricted Stock Units
Additional disclosure
Unrecognized compensation cost related to performance awards	$ 587
Number of Restricted/Performance Share Units
Restricted share units at the beginning of the period (in shares)	75,071
Granted (in shares)	19,307
Vested (in shares)	(23,713)
Forfeited (in shares)	(1,326)
Restricted share units at the end of the period (in shares)	69,339	75,071
Weighted Average Grant-Date Value
Restricted share units at the beginning of the period (in dollars per share)	$ 46.92
Granted (in dollars per share)	86.41
Vested (in dollars per share)	58.56
Forfeited (in dollars per share)	78.24
Restricted share units at the end of the period (in dollars per share)	$ 53.33	$ 46.92
Stock options
Additional disclosure
Tax benefit for the tax deduction from awards exercised	$ (1,200)	$ (1,800)	(1,600)
Performance awards
Additional disclosure
Vesting period	3 years
Period to meet the performance goals	3 years
Number of Restricted/Performance Share Units
Restricted share units at the beginning of the period (in shares)	84,649
Granted (in shares)	16,375
Performance criteria adjustment (in shares)	(670)
Vested (in shares)	(41,434)
Forfeited (in shares)	(960)
Restricted share units at the end of the period (in shares)	57,960	84,649
Weighted Average Grant-Date Value
Restricted share units at the beginning of the period (in dollars per share)	$ 51.85
Granted (in dollars per share)	89.15
Performance criteria adjustment (in dollars per share)	38.14
Vested (in dollars per share)	44.80
Forfeited (in dollars per share)	82.47
Restricted share units at the end of the period (in dollars per share)	$ 66.40	$ 51.85
GSWC | Stock options
Additional disclosure
Tax benefit for the tax deduction from awards exercised	$ (1,200)	$ (1,800)	$ (1,600)

Commitments (Details)

Commitments (Details) $ in Thousands	Dec. 31, 2020USD ($)
GSWC | Water Supply
Estimated future minimum payments
2021	$ 426
2022	426
2023	426
2024	426
2025	383
Thereafter	1,675
Total	3,762
GSWC | Water Supply | Various third parties
Purchase commitments
Remaining amount of commitment	1,900
GSWC | Water Supply | Other various third parties
Estimated future minimum payments
Total	1,900
Electric: | Electric Power Purchase Commitments [Member]
Estimated future minimum payments
Total	$ 20,100

Commitments Commitments 2 (Deta

Commitments Commitments 2 (Details) - Bear Valley Electric Service, Inc.	12 Months Ended
	Dec. 31, 2020unit
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Number of renewable energy credits that would be purchased	578,000
Minimum
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Derivative, Term of Contract	3 years
Maximum
Purchase Commitment, Excluding Long-term Commitment [Line Items]
Derivative, Term of Contract	5 years

Commitments (Details)_2

Commitments (Details)	12 Months Ended
	Dec. 31, 2020
Renewables Portfolio Standard [Member] | Bear Valley Electric Service, Inc.
Purchase commitments
Derivative, Term of Contract	ten

Contingencies (Details)

Contingencies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Contingencies
Term estimate for the environmental cleanup	2 years
Environmental Clean-Up and Remediation | GSWC
Contingencies
Amount spent in clean-up and remediation activities	$ 6.4
Amount paid by the State of California Underground Storage Tank Fund for clean-up and remediation of plant facilities	1.5
Accrued liability for the estimated additional cost to complete the clean-up at the site	$ 1.3

Leases Lease- additional inform

Leases Lease- additional information (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease liabilities	$ 2,013	$ 1,849
Operating lease liabilities	9,636	11,739
Operating lease right-of-use assets	$ 11,146	$ 13,168

Leases Supplemental lease infor

Leases Supplemental lease information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Lease, Cost	$ 2,873	$ 3,166
Operating lease right-of-use assets	11,146	13,168
Short-term Lease, Cost	$ 143	$ 159
Operating Lease, Weighted Average Remaining Lease Term	6 years 7 months 13 days	7 years 2 months 26 days
Operating Lease, Weighted Average Discount Rate, Percent	3.60%	3.50%
Operating Lease, Payments, Use	$ 27	$ 18,034

Leases Lessee Operating Lease L

Leases Lessee Operating Lease Liability Maturity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
2021	$ 2,561
2022	2,318
2023	1,825
2024	1,503
2025	1,324
Thereafter	3,925
Total lease payments	13,456
Less: imputed interest	1,807
Total lease obligations	11,649
Less: current obligations	2,013	$ 1,849
Long-term lease obligations	9,636	11,739
Operating Lease, Expense	$ 2,600	$ 2,800	$ 2,500

Business Segments (Details)

Business Segments (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Details of reportable segment
Operating revenues	$ 124,200	$ 133,688	$ 121,278	$ 109,077	$ 112,993	$ 134,496	$ 124,647	$ 101,733	$ 488,243	$ 473,869	$ 436,816
Operating Income	29,277	39,807	35,716	25,699	24,724	42,724	39,430	20,195	130,499	127,073	100,983
Interest expense, net									(20,730)	(21,337)	(19,855)
Net utility plant	1,512,043				1,415,705				1,512,043	1,415,705	1,296,310
Depreciation and amortization expense									36,850	35,397	40,425
Income Tax Expense (Benefit)									28,197	24,670	18,017
Capital additions									$ 130,423	151,940	126,561
Parent Company
Details of reportable segment
Number of reportable segments | segment									3
Operating revenues									$ 0	0	0
Operating Income									(9)	(9)	7
Interest expense, net									(330)	(539)	(451)
Net utility plant	0				0				0	0	0
Depreciation and amortization expense									0	0	0
Income Tax Expense (Benefit)									(208)	(709)	(525)
Capital additions									$ 0	0	0
GSWC
Details of reportable segment
Number of reportable segments | segment									1
Operating revenues	73,438	98,701	94,753	82,392	81,233	107,245	95,548	75,352	$ 349,284	359,378	329,608
Operating Income	17,480	$ 33,149	$ 30,175	$ 22,092	18,746	$ 36,982	$ 34,037	$ 15,327	102,896	105,092	80,562
Net utility plant	1,400,489				1,394,742				1,400,489	1,394,742
Depreciation and amortization expense									32,184	32,441	38,395
Income Tax Expense (Benefit)									21,704	20,177	13,603
GSWC | Water Service Utility Operations [Member]
Details of reportable segment
Operating revenues									330,637	319,830	295,258
Operating Income									97,896	93,895	74,342
Interest expense, net									(20,312)	(20,304)	(18,403)
Net utility plant	1,400,489				1,322,062				1,400,489	1,322,062	1,218,468
Depreciation and amortization expense									30,969	29,956	36,137
Income Tax Expense (Benefit)									20,515	17,295	12,391
Capital additions									107,355	131,353	110,934
GSWC | Electric:
Details of reportable segment
Operating revenues										39,548	34,350
Operating Income										11,197	6,220
Interest expense, net										(1,228)	(1,328)
Net utility plant					72,680					72,680	62,624
Depreciation and amortization expense										2,485	2,258
Income Tax Expense (Benefit)										2,882	1,212
Capital additions										11,499	5,420
American States Utility Services [Member] | Contracted services:
Details of reportable segment
Operating revenues									120,582	114,491	107,208
Operating Income									22,309	21,990	20,414
Interest expense, net									496	734	327
Net utility plant	22,246				$ 20,963				22,246	20,963	15,218
Depreciation and amortization expense									3,402	2,956	2,030
Income Tax Expense (Benefit)									5,201	5,202	4,939
Capital additions									$ 4,675	9,088	$ 10,207
Period of Fixed Price Contracts to Operate and Maintain Water Systems at Various Military Bases									50 years
Bear Valley Electric Service, Inc. | Electric:
Details of reportable segment
Operating revenues									$ 37,024
Operating Income									10,303
Interest expense, net									(584)
Net utility plant	$ 89,308								89,308
Depreciation and amortization expense									2,479
Income Tax Expense (Benefit)										$ 2,689
Capital additions									$ 18,393

Business Segments 2 (Details)

Business Segments 2 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting [Abstract]
Total utility plant	$ 1,512,043	$ 1,415,705	$ 1,296,310
Other assets	279,560	225,626
Total Assets	1,791,603	1,641,331
Parent Company
Segment Reporting [Abstract]
Total utility plant	0	0	0
Total Assets	759,716	811,677
GSWC
Segment Reporting [Abstract]
Total utility plant	1,400,489	1,394,742
Total Assets	1,560,782	1,522,454
Segment Reporting Information [Line Items]
Depreciation on transportation equipment	353	316	238
Contracted services: | American States Utility Services [Member]
Segment Reporting [Abstract]
Total utility plant	$ 22,246	$ 20,963	$ 15,218

Allowance for Doubtful Accoun_3

Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Changes in allowance for doubtful accounts
Balance at beginning of year	$ 916	$ 951	$ 1,041
Provision charged to expense	5,016	609	841
Accounts written off, net of recoveries	616	644	931
Balance at end of year	5,316	916	951
Components of allowance for doubtful accounts
Allowance for doubtful accounts related to accounts receivable-customer				$ 5,263	$ 857	$ 892
Allowance for doubtful accounts related to other accounts receivable				53	59	59
Total allowance for doubtful accounts	916	916	1,041	5,316	916	951
GSWC
Changes in allowance for doubtful accounts
Balance at beginning of year	916	951	865
Provision charged to expense	4,703	607	850
Provision for Doubtful Accounts transfer to BVESI	(79)	0	0
Accounts written off, net of recoveries	580	642	764
Balance at end of year	4,960	916	951
Components of allowance for doubtful accounts
Allowance for doubtful accounts related to accounts receivable-customer				4,907	857	892
Allowance for doubtful accounts related to other accounts receivable				53	59	59
Total allowance for doubtful accounts	$ 4,960	$ 951	$ 951	$ 4,960	$ 916	$ 951

Statement of Cash Flows, Supp_3

Statement of Cash Flows, Supplemental Disclosures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Taxes and Interest Paid:
Income taxes paid	$ 13,684	$ 22,496	$ 21,084
Interest paid	19,941	25,080	23,471
Non-Cash Transactions:
Accrued payables for investment in utility plant	27,861	23,736	27,403
Property installed by developers and conveyed	3,102	6,220	2,082
Noncash or Part Noncash Acquisition, Value of Assets Acquired	0	0	0
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	0	0	0
GSWC
Taxes and Interest Paid:
Income taxes paid	8,184	17,206	19,448
Interest paid	19,681	23,925	22,721
Non-Cash Transactions:
Accrued payables for investment in utility plant	25,633	23,736	27,403
Property installed by developers and conveyed	3,102	6,220	2,082
Noncash or Part Noncash Acquisition, Value of Assets Acquired	71,324	0	0
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	$ 71,344	$ 0	$ 0

Completion of Electric Utilit_3

Completion of Electric Utility Reorganization Plan (Details) - USD ($)	Jul. 01, 2020	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Gain (loss) on transfer of net assets	$ 0
Electric												$ 37,024,000	$ 39,548,000	$ 34,350,000
Net Income		$ 20,211,000	$ 26,530,000	$ 25,612,000	$ 14,072,000	$ 16,700,000	$ 28,006,000	$ 26,784,000	$ 12,852,000			86,425,000	84,342,000	63,871,000
Net cash provided from operating activities												122,170,000	116,864,000	136,774,000
Net cash used in investing activities (capital expenditures)												(131,610,000)	(153,195,000)	(128,042,000)
Net cash provided from financing activities												44,843,000	30,524,000	(1,805,000)
Maximum borrowing capacity		260,000,000								$ 260,000,000		$ 260,000,000
Revision of Prior Period, Adjustment
Restructuring Cost and Reserve [Line Items]
Operating income						3,700,000
Bear Valley Electric Service, Inc.
Restructuring Cost and Reserve [Line Items]
Gain (loss) on transfer of net assets	0
Income tax liability	0
Debt instrument, term										3 years		3 years
Maximum borrowing capacity	35,000,000
Fair value of amount outstanding		20,200,000								$ 20,200,000		$ 20,200,000
Incremental expansion of borrowing capacity	35,000,000	15,000,000								15,000,000		15,000,000
Dividends		12,400,000
Bear Valley Electric Service, Inc. | Electric
Restructuring Cost and Reserve [Line Items]
Electric										18,377,000
Operating expenses										13,074,000
Operating income										5,303,000
Net Income										3,870,000
Net cash provided from operating activities										1,887,000
Net cash used in investing activities (capital expenditures)										(9,339,000)
Net cash provided from financing activities										7,799,000
Net change in cash and cash equivalents										347,000
Cash and cash equivalents, end of period	20,000	367,000								$ 367,000		367,000
GSWC
Restructuring Cost and Reserve [Line Items]
Electric												18,647,000	39,548,000	34,350,000
Net Income		$ 11,707,000	$ 21,143,000	$ 20,919,000	$ 11,202,000	$ 11,981,000	$ 23,362,000	$ 22,298,000	$ 9,022,000			64,971,000	66,663,000	48,012,000
Net cash provided from operating activities												110,337,000	96,628,000	120,439,000
Net cash used in investing activities (capital expenditures)												(117,684,000)	(144,188,000)	(117,898,000)
Net cash provided from financing activities												42,524,000	43,774,000	$ 1,432,000
Dividends												$ 71,344,000
GSWC | Electric
Restructuring Cost and Reserve [Line Items]
Electric											$ 21,510,000		$ 2,510,000
Operating expenses											13,153,000
Operating income											8,357,000
Net Income											$ 5,422,000
Bear Valley Electric Service, Inc.
Restructuring Cost and Reserve [Line Items]
Net assets transferred	$ 71,300,000

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								6 Months Ended		12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating revenues	$ 124,200	$ 133,688	$ 121,278	$ 109,077	$ 112,993	$ 134,496	$ 124,647	$ 101,733			$ 488,243	$ 473,869	$ 436,816
Net Income	$ 20,211	$ 26,530	$ 25,612	$ 14,072	$ 16,700	$ 28,006	$ 26,784	$ 12,852			$ 86,425	$ 84,342	$ 63,871
Earnings Per Share, Basic	$ 0.55	$ 0.72	$ 0.69	$ 0.38	$ 0.45	$ 0.76	$ 0.72	$ 0.35			$ 2.34	$ 2.28	$ 1.73
Earnings Per Share, Diluted	$ 0.54	$ 0.72	$ 0.69	$ 0.38	$ 0.45	$ 0.76	$ 0.72	$ 0.35			$ 2.33	$ 2.28	$ 1.72
Operating Income	$ 29,277	$ 39,807	$ 35,716	$ 25,699	$ 24,724	$ 42,724	$ 39,430	$ 20,195			$ 130,499	$ 127,073	$ 100,983
GSWC
Operating revenues	73,438	98,701	94,753	82,392	81,233	107,245	95,548	75,352			349,284	359,378	329,608
Net Income	11,707	21,143	20,919	11,202	11,981	23,362	22,298	9,022			64,971	66,663	48,012
Operating Income	$ 17,480	$ 33,149	$ 30,175	22,092	$ 18,746	$ 36,982	$ 34,037	$ 15,327			102,896	105,092	80,562
Water Service Utility Operations [Member] | GSWC
Operating revenues											330,637	319,830	295,258
Retroactive pretax income adjustment due to GRC delay				$ 4,000
Operating Income											$ 97,896	93,895	74,342
Electric: | GSWC
Operating revenues												39,548	34,350
Net Income										$ 5,422
Retroactive pretax income adjustment due to GRC delay									$ 1,400			2,300
Operating Income												$ 11,197	$ 6,220

SCHEDULE I - CONDENSED FINANC_2

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 36,737	$ 1,334	$ 7,141	$ 214
Income taxes receivable and other receivables	103	5,685
Total current assets	157,115	122,456
Deferred taxes and other assets	10,597	7,702
Total Assets	1,791,603	1,641,331
Liabilities and Capitalization
Notes payable to bank	0	5,000
Income taxes payable	6,783	95
Other Liabilities, Current	10,437	10,341
Total current liabilities	118,572	115,998
Notes payable to banks	134,200	200,000
Total other credits	591,010	642,807
Common shareholders' equity	641,673	601,530	$ 558,223	529,945
Total capitalization	1,082,021	882,526
Liabilities and Equity, Total	$ 1,791,603	$ 1,641,331
Dividends Declared Per Common Share (in dollars per share)	$ 1.28	$ 1.16	$ 1.06
Income tax expense	$ 28,197	$ 24,670	$ 18,017
Parent Company
Assets
Cash and cash equivalents	441	310	$ 34	$ 48
Income Taxes Receivable	72	0
Inter-company loan receivables	32,819	185,094
Total current assets	33,332	185,404
Investments in subsidiaries	716,627	616,725
Deferred taxes and other assets	9,757	9,548
Total Assets	759,716	811,677
Liabilities and Capitalization
Notes payable to bank	0	5,000
Income taxes payable	2,123	3,259
Other Liabilities, Current	272	274
Total current liabilities	2,395	8,533
Notes payable to banks	114,000	200,000
Income taxes payable and other liabilities	1,648	1,614
Total other credits	115,648	201,614
Common shareholders' equity	641,673	601,530
Total capitalization	641,673	601,530
Liabilities and Equity, Total	$ 759,716	$ 811,677
Dividends Declared Per Common Share (in dollars per share)	$ 1.280	$ 1.160	$ 1.060
Income tax expense	$ (208)	$ (709)	$ (525)

SCHEDULE I - CONDENSED FINANC_3

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT 2 (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed financial statements
Income tax expense									$ 28,197	$ 24,670	$ 18,017
Net Income	$ 20,211	$ 26,530	$ 25,612	$ 14,072	$ 16,700	$ 28,006	$ 26,784	$ 12,852	$ 86,425	$ 84,342	$ 63,871
Weighted Average Number of Shares Outstanding (in shares)									36,880	36,814	36,733
Earnings Per Share, Basic	$ 0.55	$ 0.72	$ 0.69	$ 0.38	$ 0.45	$ 0.76	$ 0.72	$ 0.35	$ 2.34	$ 2.28	$ 1.73
Weighted Average Number of Diluted Common Shares Outstanding									36,995	36,964	36,936
Earnings Per Share, Diluted	$ 0.54	$ 0.72	$ 0.69	$ 0.38	$ 0.45	$ 0.76	$ 0.72	$ 0.35	$ 2.33	$ 2.28	$ 1.72
Dividends Paid Per Common Share									$ 1.28	$ 1.16	$ 1.06
Parent Company
Condensed financial statements
Operating revenues and other income									$ 0	$ 0	$ 0
Operating Expenses and Other Expenses									90	314	305
Operating income / (loss)									(90)	(314)	(305)
Equity in earnings of subsidiaries									86,307	83,947	63,651
Closed Block Operations, Results before Income Taxes									86,217	83,633	63,346
Income tax expense									(208)	(709)	(525)
Net Income									$ 86,425	$ 84,342	$ 63,871
Earnings Per Share, Basic									$ 2.34	$ 2.28	$ 1.73
Earnings Per Share, Diluted									2.33	2.28	1.72
Dividends Paid Per Common Share									$ 1.280	$ 1.160	$ 1.060

SCHEDULE I - CONDENSED FINANC_4

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT 3 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed financial statements
Net Cash Provided by (Used in) Operating Activities	$ 122,170	$ 116,864	$ 136,774
Cash Flows From Investing Activities:
Net Cash Provided by (Used in) Investing Activities	(131,610)	(153,195)	(128,042)
Cash Flows From Financing Activities:
Proceeds from stock option exercises	30	519	546
Dividends paid	(47,206)	(42,702)	(38,937)
Net Cash Provided by (Used in) Financing Activities	44,843	30,524	(1,805)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	35,403	(5,807)	6,927
Cash and cash equivalents, beginning of period	1,334	7,141	214
Cash and cash equivalents, end of year	36,737	1,334	7,141
Parent Company
Condensed financial statements
Net Cash Provided by (Used in) Operating Activities	47,307	40,459	79,877
Cash Flows From Investing Activities:
Loans (made to)/repaid from, wholly-owned subsidiaries	151,000	(107,500)	(30,500)
Investment Company, Net Assets, Period Increase (Decrease)	(60,000)	0	(47,500)
Net Cash Provided by (Used in) Investing Activities	91,000	(107,500)	(78,000)
Cash Flows From Financing Activities:
Proceeds from stock option exercises	30	519	546
Net change in notes payable to banks	91,000	(109,500)	(36,500)
Repayments of Related Party Debt	(6,000)	0	0
Proceeds from Related Party Debt	6,000	0	0
Dividends paid	(47,206)	(42,702)	(38,937)
Net Cash Provided by (Used in) Financing Activities	(138,176)	67,317	(1,891)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect	131	276	(14)
Cash and cash equivalents, beginning of period	310	34	48
Cash and cash equivalents, end of year	$ 441	$ 310	$ 34

SCHEDULE I - CONDENSED FINANC_5

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT 4 (Details)	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Note payable to banks
Line of Credit Facility, Current Borrowing Capacity	$ 200,000,000
Maximum borrowing capacity	260,000,000
Notes Payable to Bank	134,200,000
Maximum borrowing capacity	260,000,000
Short-term borrowing activities (excluding letters of credit)
Notes payable to banks	0	$ 5,000,000
Parent [Member]
Note payable to banks
Line of Credit Facility, Current Borrowing Capacity	$ 30,000,000
Short-term borrowing (excluding letters of credit)
Short-term borrowing activities (excluding letters of credit)
Interest Rate at the end of the period (as a percent)		2.44%
Weighted Average Annual Interest Rate (as a percent)	1.47%	2.88%
Maximum Amount Outstanding	$ 249,200,000	$ 205,500,000
Average Amount Outstanding	$ 162,995,000	167,392,000
Short-term borrowing (excluding letters of credit) | Minimum
Short-term borrowing activities (excluding letters of credit)
Interest Rate at the end of the period (as a percent)	1.19%
Short-term borrowing (excluding letters of credit) | Maximum
Short-term borrowing activities (excluding letters of credit)
Interest Rate at the end of the period (as a percent)	1.90%
Long-term Debt [Member]
Short-term borrowing activities (excluding letters of credit)
Notes Payable, Current	$ 134,200,000	205,000,000
Syndicated revolving credit facility
Note payable to banks
Variable rate basis	Euro rate
Syndicated revolving credit facility | Minimum
Note payable to banks
Interest coverage ratio	3.25
Syndicated revolving credit facility | Maximum
Note payable to banks
Total funded debt ratio	0.65
Parent Company
Note payable to banks
Line of Credit Facility, Current Borrowing Capacity	$ 200,000,000
Short-term borrowing activities (excluding letters of credit)
Notes payable to banks	$ 0	$ 5,000,000
Parent Company | Short-term borrowing (excluding letters of credit)
Short-term borrowing activities (excluding letters of credit)
Interest Rate at the end of the period (as a percent)	1.19%	2.44%
Weighted Average Annual Interest Rate (as a percent)	1.47%	2.88%
Maximum Amount Outstanding	$ 249,000,000	$ 205,500,000
Average Amount Outstanding	160,495,000	167,392,000
Parent Company | Long-term Debt [Member]
Short-term borrowing activities (excluding letters of credit)
Notes Payable, Current	$ 114,000,000	205,000,000
Parent Company | Syndicated revolving credit facility
Note payable to banks
Total funded debt ratio	0.47
Interest coverage ratio	7.74
Parent Company | Syndicated revolving credit facility | Minimum
Note payable to banks
Total funded debt ratio	0.65
Interest coverage ratio	3.25
Parent Company | Syndicated revolving credit facility | Maximum
Note payable to banks
Total funded debt ratio	1
Parent Company | Syndicated revolving credit facility | Letters of credit
Note payable to banks
Maximum borrowing capacity	$ 25,000,000
Maximum borrowing capacity	25,000,000
Letter of credit, amount	$ 455,000
Letter of credit fee (as a percent)	0.65%
Subsidiaries [Member]
Short-term borrowing activities (excluding letters of credit)
Dividends paid	$ (47,300,000)	(42,700,000)	$ (79,000,000)
GSWC
Short-term borrowing activities (excluding letters of credit)
Dividends paid	$ (22,500,000)	$ (20,200,000)	$ (68,850,000)