Stock-Based Compensation - Summary of Restricted Stock, Stock Grants, Stock Units and Performance Shares (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted Stock Units, Stock Grants, and Stock Units
Stocks granted and the weighted average fair value
Units granted (in shares)	118,403	109,106	132,997
Grant date fair value (in dollars per share)	$ 71.70	$ 89.15	$ 77.51
Number of granted awards to be settled in cash (in shares)	45,646	48,972	66,252
Performance Shares
Stocks granted and the weighted average fair value
Units granted (in shares)	122,830	142,874	171,708
Grant date fair value (in dollars per share)	$ 104.74	$ 92.16	$ 76.56