Earnings Per Share - (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Reconciliation of number of shares used in calculation of basic and diluted earnings per share
Weighted average number of common shares outstanding	80,691,996	80,421,478	80,649,824	80,731,889
Effect of non-participatory equity compensation (in shares)	34,442	40,000	34,442	40,000
Weighted average number of common shares outstanding, including effect of dilutive securities	80,726,438	80,461,478	80,684,266	80,771,889