Significant Accounting Policies - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended		12 Months Ended
	Mar. 15, 2021	Feb. 28, 2021	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Accounting Policies [Abstract]
Common stock, shares authorized (in shares)			32,000,000		32,000,000
Common stock, par value (in dollars per share)			$ 0.01		$ 0.01
Common stock, shares issued (in shares)			24,651,205		24,418,939
Common stock, shares outstanding (in shares)			24,651,205		24,418,939
Preferred stock, shares authorized (in shares)			8,000,000		8,000,000
Issued shares of preferred stock			0		0
Outstanding shares of preferred stock			0		0
Common stock dividends declared (in dollars per share)		$ 0.60	$ 0.60	$ 0.60
Common stock dividends paid (in dollars per share)	$ 0.60
Accumulated other comprehensive income net of tax			$ 40,064,000		$ 48,880,000
Tax from unrealized gains and losses on marketable securities			300,000		$ 300,000
Reclassifications from AOCI			$ 0