Computation of Basic and Diluted Earnings per Common Share (Parenthetical) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
EPS Performance-based Restricted Stock Units
Computation Of Earnings Per Share [Line Items]
Contingently issuable shares excluded from calculation of weighted average common shares outstanding	45	45	46
Operating Cash Flow Performance Based Restricted Stock Units
Computation Of Earnings Per Share [Line Items]
Contingently issuable shares excluded from calculation of weighted average common shares outstanding	37
Laser Quantum | Restricted Stock
Computation Of Earnings Per Share [Line Items]
Contingently issuable shares excluded from calculation of weighted average common shares outstanding	213	213	213