Summary of Significant Accounting Policies - Stockholder's Equity (Details)	1 Months Ended		9 Months Ended
	Jul. 31, 2020 USD ($) shares	Jun. 30, 2020 USD ($) $ / shares shares	Sep. 30, 2021 vote $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares
Accounting Policies [Abstract]
Total number of shares of all classes of stock authorized (in shares)			110,000,000
Common stock, par value (in dollars per share) | $ / shares			$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)			10,000,000
Common stock, shares authorized (in shares)			100,000,000	100,000,000
Votes per share held | vote			1
Ordinary share per dividend (in dollars per share) | $ / shares		$ 0.04
Cash dividends | $				$ 607,000
Treasury stock acquired (in shares)	13,000	10,000
Payments to acquire treasury stock | $	$ 141,000	$ 107,000