Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 100.4	$ 101.7
Increase (decrease) in annual rate per capita cost of covered healthcare benefits, next year	7.50%
Increase (decrease) in annual rate per capita cost of covered healthcare benefits, 2023-2028	0.50%
Increase (decrease) in annual rate per capita cost of covered healthcare benefits, 2028	4.50%
Number of hours required to participate in contribution plan	1,000
Percent of participants contributions matched by company, below one percent of participants compensation	100.00%
Percent of participants contributions matched by company, above one percent of participants compensation	50.00%
Threshold percentage of participants compensation at which matching decreases	1.00%
Matching contributions, percent	6.00%
Matching contributions	$ 0.7	0.7	$ 0.7
Discretionary contributions, percent	5.00%
Discretionary contributions	$ 0.8	$ 0.7	$ 0.7
Maximum number of shares authorized for grant	300,000
Equity Securities [Member] | Middlesex [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocation of plan assets	0.00%	1.60%
Common stock in plan, value	$ 0.0	$ 1.4
Other Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocation of plan assets	100.00%	100.00%
Benfit plan, Cash contributions	$ 0.8
Other Benefits Plan [Member] | Scenario Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Benfit plan, Cash contributions	$ 0.8
Pension Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocation of plan assets	100.00%	100.00%
Benfit plan, Cash contributions	$ 3.4
Pension Benefit Plan [Member] | Scenario Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Benfit plan, Cash contributions	$ 3.4