Deferred Compensation Plans - Summary of Changes in Deferred Compensation Plan Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Postemployment Benefits [Roll Forward]
Balance, beginning of year	$ 3,234	$ 2,408	$ 2,503
Deferrals, dividends, and changes in fair value	(70)	904	64
Deferred compensation payments	(79)	(78)	(159)
Balance, end of year	$ 3,085	$ 3,234	$ 2,408