Impact of Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
New Accounting Pronouncements [Abstract]
Operating expenses	$ 6,504	$ 6,128
Other pension costs	321	305
ASU No. 2017-07 [Member]
New Accounting Pronouncements [Abstract]
Operating expenses	(321)	(305)
Other pension costs	$ 321	$ 305

Amount of expense (reversal of expense) for net periodic benefit cost components, excluding service cost component, of defined benefit plan. Amount includes, but is not limited to, interest cost, expected (return) loss on plan asset, amortization of prior service cost (credit), amortization of (gain) loss, amortization of transition (asset) obligation, settlement (gain) loss, curtailment (gain) loss and certain termination benefits.

No definition available.

Name:	yorw_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingTheServiceCostComponent
Namespace Prefix:	yorw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration