CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Revenues	$ 116,665,000	$ 107,054,000	$ 98,667,000
Operating Expenses
Operation and Maintenance	52,006,000	47,130,000	43,155,000
Depreciation	18,692,000	16,684,000	13,905,000
Income Taxes	(2,008,000)	(1,993,000)	2,570,000
Taxes Other Than Income Taxes	11,874,000	10,941,000	9,796,000
Total Operating Expenses	80,564,000	72,762,000	69,426,000
Net Operating Revenues	36,101,000	34,292,000	29,241,000
Other Utility Income, Net of Taxes	1,078,000	824,000	744,000
Total Utility Operating Income	37,179,000	35,116,000	29,985,000
Other Income (Deductions), Net of Taxes
Gain (Loss) on Real Estate Transactions	629,000	33,000	(54,000)
Non-Water Sales Earnings	1,807,000	1,167,000	1,219,000
Allowance for Funds Used During Construction	465,000	774,000	1,198,000
Merger and Acquisition Costs	(10,819,000)	(392,000)	(302,000)
Other	(1,442,000)	(2,803,000)	(1,743,000)
Total Other Income, Net of Taxes	(9,360,000)	(1,221,000)	318,000
Interest and Debt Expense
Interest on Long-Term Debt	10,387,000	9,054,000	7,714,000
Interest Expense, Other	537,000
Other Interest Charges		(359,000)	(922,000)
Amortization of Debt Expense	200,000	146,000	124,000
Total Interest and Debt Expense	11,124,000	8,841,000	6,916,000
Net Income	16,695,000	25,054,000	23,387,000
Preferred Stock Dividend Requirement	10,000	38,000	38,000
Net Income Applicable to Common Stock	$ 16,685,000	$ 25,016,000	$ 23,349,000
Weighted Average Common Shares Outstanding:
Basic (in shares)	11,914	11,540	11,009
Diluted (in shares)	12,065	11,762	11,228
Earnings Per Common Share:
Basic (in dollars per share)	$ 1.40	$ 2.17	$ 2.12
Diluted (in dollars per share)	$ 1.38	$ 2.13	$ 2.08
Adjustment to post-retirement benefit plans, net of tax benefit (expense) of $15, $(505), and $735 in 2016, 2015, and 2014, respectively	$ 127,000	$ 289,000	$ (24,000)
Unrealized Investment gain (loss), net of tax (expense) benefit of $(22), $62 and $(25), in 2016, 2015, and 2014, respectively	(184,000)	207,000	35,000
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(57,000)	496,000	11,000
Comprehensive Income	$ 16,638,000	$ 25,550,000	$ 23,398,000