Valuation and Qualifying Accounts and Reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	$ 272	$ 190	$ 200
Opening balance, SJWNE, LLC	1,283	0	0
Charged to expense	520	430	399
Accounts written off	(875)	(650)	(675)
Recoveries of accounts written off	312	302	266
Ending Balance	1,512	272	190
SEC Schedule, 12-09, Reserve, Legal [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	2,181	1,892	2,105
Charged to expense	3,221	480	528
Accounts written off	(135)	1	(245)
Payments	(2,369)	(192)	(496)
Ending Balance	$ 2,898	$ 2,181	$ 1,892