Unaudited Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2019

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

Summarized quarterly financial data is as follows:

	2019 Quarter Ended
	March		June	September	December
Operating revenue	$	77,682	102,965	113,997	125,838
Operating income	12,408		21,971	17,084	6,016
SJW Group net income	5,873		13,538	9,478	(5,486	)
Comprehensive income	5,873		13,538	9,478	(5,360	)
Earnings per share:
—Basic	0.21		0.48	0.33	(0.20	)
—Diluted	0.21		0.47	0.33	(0.19	)
Market price range of stock:
—High	63.76		63.40	69.23	74.47
—Low	54.74		59.83	61.23	67.13
Dividend per share	0.30		0.30	0.30	0.30