Business Segments (Tables)

12 Months Ended

Dec. 31, 2017

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.

	As Of And For The Year Ended December 31, 2017
	GSWC				ASUS		AWR			Consolidated
(dollars in thousands)	Water		Electric		Contracts		Parent			AWR
Operating revenues	$	306,332	$	33,969	$	100,302	$	—		$	440,603
Operating income (loss)	98,797		7,251		21,124		(96		)	127,076
Interest expense, net	18,909		1,380		255		248			20,792
Utility Plant	1,137,995		59,945		7,052		—			1,204,992
Depreciation and amortization expense (1)	35,706		2,146		1,179		—			39,031
Income tax expense/(benefit)	32,212		1,847		7,136		(2,221		)	38,974
Capital additions	104,546		5,941		2,639		—			113,126

	As Of And For The Year Ended December 31, 2016
	GSWC				ASUS		AWR			Consolidated
(dollars in thousands)	Water		Electric		Contracts		Parent			AWR
Operating revenues	$	302,931	$	35,771	$	97,385	$	—		$	436,087
Operating income (loss)	87,911		7,908		18,916		(19		)	114,716
Interest expense, net	19,696		1,337		68		134			21,235
Utility Plant	1,089,031		56,280		5,615		—			1,150,926
Depreciation and amortization expense (1)	35,777		2,027		1,046		—			38,850
Income tax expense/(benefit)	25,894		2,715		6,672		(546		)	34,735
Capital additions	120,850		7,063		1,954		—			129,867

	As Of And For The Year Ended December 31, 2015
	GSWC				ASUS		AWR			Consolidated
(dollars in thousands)	Water		Electric		Contracts		Parent			AWR
Operating revenues	$	328,511	$	36,039	$	94,091	$	—		$	458,641
Operating income (loss)	94,213		6,196		18,091		(11		)	118,489
Interest expense, net	19,468		1,090		26		46			20,630
Utility Plant	1,005,114		51,002		4,678		—			1,060,794
Depreciation and amortization expense (1)	39,190		1,703		1,140		—			42,033
Income tax expense/(benefit)	30,302		2,170		6,069		(810		)	37,731
Capital additions	77,440		8,704		1,179		—			87,323

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,
	2017		2016
Total utility plant	$	1,204,992	$	1,150,926
Other assets	211,742		319,567
Total consolidated assets	$	1,416,734	$	1,470,493