CONSOLIDATED STATEMENTS OF CAPITALIZATION (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Common Shareholders' Equity:
Common shares, no par value	$ 253,961	$ 249,322
Earnings reinvested in the business	238,443	205,257
Common shareholders' equity	492,404	454,579
Long-Term Debt
Total	332,377	335,791
Less: Current maturities	(6,298)	(3,328)
Long-Term Debt	326,079	332,463
Total capitalization	818,483	787,042
GSWC
Common Shareholders' Equity:
Common shares, no par value	233,721	231,480
Earnings reinvested in the business		184,777
Common shareholders' equity	437,613	416,257
Long-Term Debt
Total	332,377	335,791
Less: Current maturities	(6,298)	(3,328)
Long-Term Debt	326,079	332,463
Total capitalization	763,692	748,720
6.64% notes due 2013
Long-Term Debt
Total	0	1,100
6.64% notes due 2013 | GSWC
Long-Term Debt
Total	0	1,100
6.80% notes due 2013
Long-Term Debt
Total	0	2,000
6.80% notes due 2013 | GSWC
Long-Term Debt
Total	0	2,000
6.87% notes due 2023
Long-Term Debt
Total	5,000	5,000
6.87% notes due 2023 | GSWC
Long-Term Debt
Total	5,000	5,000
7.00% notes due 2023
Long-Term Debt
Total	10,000	10,000
7.00% notes due 2023 | GSWC
Long-Term Debt
Total	10,000	10,000
6.81% notes due 2028
Long-Term Debt
Total	15,000	15,000
6.81% notes due 2028 | GSWC
Long-Term Debt
Total	15,000	15,000
6.59% notes due 2029
Long-Term Debt
Total	40,000	40,000
6.59% notes due 2029 | GSWC
Long-Term Debt
Total	40,000	40,000
7.875% notes due 2030
Long-Term Debt
Total	20,000	20,000
7.875% notes due 2030 | GSWC
Long-Term Debt
Total	20,000	20,000
7.23% notes due 2031
Long-Term Debt
Total	50,000	50,000
7.23% notes due 2031 | GSWC
Long-Term Debt
Total	50,000	50,000
6.00% notes due 2041
Long-Term Debt
Total	62,000	62,000
6.00% notes due 2041 | GSWC
Long-Term Debt
Total	62,000	62,000
9.56% private placement notes due 2031
Long-Term Debt
Total	28,000	28,000
9.56% private placement notes due 2031 | GSWC
Long-Term Debt
Total	28,000	28,000
5.87% private placement notes due 2028
Long-Term Debt
Total	40,000	40,000
5.87% private placement notes due 2028 | GSWC
Long-Term Debt
Total	40,000	40,000
6.70% private placement notes due 2019
Long-Term Debt
Total	40,000	40,000
6.70% private placement notes due 2019 | GSWC
Long-Term Debt
Total	40,000	40,000
5.50% tax-exempt obligation due 2026
Long-Term Debt
Total	7,730	7,730
5.50% tax-exempt obligation due 2026 | GSWC
Long-Term Debt
Total	7,730	7,730
Tax-Exempt Variable Rate Obligation due 2014
Long-Term Debt
Total	6,000	6,000
Tax-Exempt Variable Rate Obligation due 2014 | GSWC
Long-Term Debt
Total	6,000	6,000
Tax-Exempt State Water Project due 2035
Long-Term Debt
Total	4,190	4,453
Tax-Exempt State Water Project due 2035 | GSWC
Long-Term Debt
Total	4,190	4,453
Variable Rate Obligation due 2018
Long-Term Debt
Total	161	196
Variable Rate Obligation due 2018 | GSWC
Long-Term Debt
Total	161	196
American Recovery and Reinvestment Act Obligation due 2033
Long-Term Debt
Total	4,269	4,259
American Recovery and Reinvestment Act Obligation due 2033 | GSWC
Long-Term Debt
Total	4,269	4,259
Capital lease obligations
Long-Term Debt
Total	27	53
Capital lease obligations | GSWC
Long-Term Debt
Total	$ 27	$ 53