Shareholders' Equity - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 07, 2019
Equity Class Of Treasury Stock [Line Items]
Treasury shares authorized to be purchased				$ 25,000,000
Common stock repurchased, shares	342,731	420,770	342,100
Common stock repurchased, value	$ 8,080,000	$ 11,746,000	$ 9,440,000
Shares available for future purchases	$ 5,740,000
Previous Plan
Equity Class Of Treasury Stock [Line Items]
Common stock repurchased, value		566,000
Recent Board-Authorized Share Repurchase Program
Equity Class Of Treasury Stock [Line Items]
Common stock repurchased, value		$ 11,180,000