Net Income Per Common Share (Narrative) (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Average common shares outstanding, included in computation	9,022,040	9,091,179	9,067,879	9,464,482
Treshold	$ 42.41		$ 42.41
Minimum [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Number Of SharesTo Be Issued Basic Stock Purchase Contracts			8,964,213