Earnings Per Share - Reconciliation of Number of Common Stock used in Computing Basic and Diluted Earning Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Weighted Average Number Of Shares Outstanding [Abstract]
Weighted average shares outstanding - basic	115,820,522	117,610,178	116,157,336	118,330,176
Dilutive effect of share-based awards	740,720	749,706	749,236	752,552
Weighted average shares outstanding - diluted	116,561,242	118,359,884	116,906,572	119,082,728