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Summary of Significant Accounting Policies (Tables) - GSWC | 12 Months Ended
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Dec. 31, 2017
Summary of significant accounting policies |
Schedule of estimated useful lives of utility plant, as authorized by the CPUC | Estimated useful lives of GSWC’s 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 estimates of the fair value of long-term debt | The table below estimates the fair value of long-term debt issued by GSWC. Rates available to GSWC at December 31, 2017 and 2016 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.
|  | 2017 |  | 2016
(dollars in thousands) |  | Carrying Amount |  | Fair Value |  | Carrying Amount |  | Fair Value
Long-term debt—GSWC (1) |  | $ | 325,265 |  |  | $ | 424,042 |  |  | $ | 325,582 |  |  | $ | 423,124 |
Schedule of long-term debt measured at fair value | 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, 2017:
(dollars in thousands) |  | Level 1 |  | Level 2 |  | Level 3 |  | Total
Long-term debt—GSWC |  | — |  |  | $ | 424,042 |  |  | — |  |  | $ | 424,042 |

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- Definition Tabular disclosure of liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, by class that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). Where the quoted price in an active market for the identical liability is not available, the Level 1 input is the quoted price of an identical liability when traded as an asset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19190-110258 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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- Definition Tabular disclosure of information pertaining to carrying amount and estimated fair value of short-term and long-term debt instruments or arrangements, including but not limited to, identification of terms, features, and collateral requirements. + References No definition available. + Details
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- Definition Tabular disclosure of public utility physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, balances by class of assets, deprecation expense and method used, including composite depreciation, and accumulated deprecation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=84167750&loc=d3e42232-110370 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.13(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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