CONDENSED CONSOLIDATED STATEMENTS OF LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Operating revenue	$ 125,563	$ 126,111
Operations:
Water production costs	53,976	45,592
Administrative and general	29,680	29,097
Other operations	13,974	17,821
Maintenance	7,073	6,455
Depreciation and amortization	24,492	22,368
Income tax benefit	(3,937)	(2,991)
Property and other taxes	7,228	7,293
Total operating (income) expenses	132,486	125,635
Net operating (loss) income	(6,923)	476
Other income and expenses:
Non-regulated revenue	3,827	4,901
Non-regulated expenses	(8,454)	(2,219)
Other components of net periodic benefit cost	(1,430)	(1,259)
Allowance for equity funds used during construction	1,614	1,533
Income tax benefit (expense) on other income and expenses	913	(828)
Net other (loss) income	(3,530)	2,128
Interest expense:
Interest expense	10,798	11,075
Allowance for borrowed funds used during construction	(944)	(831)
Net interest expense	9,854	10,244
Net (loss) income	$ (20,307)	$ (7,640)
Loss per share:
Basic (in dollars per share)	$ (0.42)	$ (0.16)
Diluted (in dollars per share)	$ (0.42)	$ (0.16)
Weighted average shares outstanding:
Basic (in shares)	48,583	48,086
Diluted (in shares)	48,583	48,086