Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Significant Accounting Policies [Abstract]

Utility Plant

The following remaining lives are used for financial reporting purposes:

	December 31,				Approximate range
Utility Plant Asset Category	2017		2016		of remaining lives
Mains and accessories	$	182,927	$	176,068	10 – 83 years
Services, meters and hydrants		71,183		68,510	19 – 54 years
Operations structures, reservoirs and water tanks		53,610		46,494	11 – 37 years
Pumping and treatment equipment		29,814		29,459	2 – 33 years
Office, transportation and operating equipment		12,787		12,360	3 – 20 years
Land and other non-depreciable assets		3,196		3,172	-
Utility plant in service		353,517		336,063
Construction work in progress		12,250		7,349	-
Total Utility Plant	$	365,767	$	343,412

Regulatory Assets and Liabilities

Regulatory assets and liabilities are comprised of the following:

	December 31,				Remaining
	2017		2016		Recovery Periods
Assets
Income taxes	$	18,564	$	20,609	Various
Postretirement benefits		5,382		7,471	5 – 10 years
Unrealized swap losses		2,172		2,264	1 – 12 years
Utility plant retirement costs		3,994		2,679	5 years
Customer-owned lead service line replacements		191		-	Not yet known
Service life study expenses		23		4	5 years
Rate case filing expenses		5		-	Not yet known
	$	30,331	$	33,027
Liabilities
Excess accumulated deferred income taxes  on accelerated depreciation	$	14,348	$	-	Not yet known
Income taxes		6,260		753	1 – 50 years
IRS TPR catch-up deduction		3,887		3,887	Not yet known
	$	24,495	$	4,640