Equity Compensation Plans - Summary of Activity Related to Executive Deferred Compensation Plan (Details) - Executive Deferred Compensation Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Compensation Cash-based Arrangements, Liability, Current and Noncurrent [Roll Forward]
Balance at beginning of period	$ 2,454	$ 2,484	$ 2,171
New deferrals	726	789	759
Accrued interest	42	68	82
Withdrawals	(933)	(887)	(528)
Balance at End of Period	$ 2,289	$ 2,454	$ 2,484