Income taxes	3 Months Ended
	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income taxes	Income taxesThe Company’s and the Utilities’ effective tax rates (combined federal and state income tax rates) were 20% and 21%, respectively, for the three months ended March 31, 2022. These rates differed from the combined statutory rates, due primarily to the Utilities’ amortization of excess deferred income taxes related to the provision in the Tax Act that lowered the federal income tax rate from 35% to 21%, the tax benefits derived from the low income housing tax credit investments and the non-taxability of the bank-owned life insurance income. The Company’s and the Utilities’ effective tax rates were 19% and 20%, respectively, for the three months ended March 31, 2021. In August 2020, the Internal Revenue Service notified the Company that its 2017 and 2018 income tax returns would be examined. The Company was previously audited every year through 2011, at which time the IRS changed their internal policies regarding audit frequency. The audit is still in progress and the Company has responded to all information requests received. The Company has not been notified of any material audit adjustments to date.