Executive Deferred Compensation Plan (Details) - Executive [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Executive Deferred Compensation Plan [Abstract]
Percentage of matching contribution maximum	10.00%
Percentage of compensation deferred, maximum	80.00%
Percentage of bonus deferred, maximum	100.00%
Percentage vested after ten years of service	50.00%
Number of years of service to attain fifty percent vesting	10 years
Percentage vested per year after ten years of service	5.00%
Minimum age for unvested company contributions to fully vest	60 years
Compensation expense	$ 1.8	$ 1.1	$ 1.5
Long-term deferred compensation liability	43.2	36.4
Investment in Rabbi Trust	$ 41.7	$ 35.6