OTHER INCOME AND EXPENSES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other income and expenses
Revenue	$ 18,272	$ 15,898	$ 16,585
Expense	22,787	9,390	11,445
New development expense	5,400
Litigation gain		1,500
Operating and maintenance revenue
Other income and expenses
Revenue	10,392	8,621	8,430
Expense	11,895	8,847	9,061
Leases
Other income and expenses
Revenue	2,467	2,015	1,923
Expense	135	182	204
Design and construction
Other income and expenses
Revenue	1,273	1,918	1,792
Expense	1,202	1,635	1,473
Meter reading and billing
Other income and expenses
Revenue	391	256	242
Expense	157	(6)	62
Interest income
Other income and expenses
Revenue	133	68	18
Expense	0	0	0
Change in value of life insurance contracts loss (gain)
Other income and expenses
Revenue	0	0	0
Expense	2,340	(3,057)	(1,026)
Other non-regulated income and expenses
Other income and expenses
Revenue	3,616	3,020	4,180
Expense	$ 7,058	$ 1,789	$ 1,671