Deferred Revenue (Tables)

6 Months Ended

Jun. 30, 2021

Deferred Revenue Disclosure [Abstract]

Summary of Changes in Deferred Revenue

The following table presents the changes in deferred revenue for the periods presented (in thousands):

	Six Months Ended June 30,
	2021			2020
Balance at beginning of period	$	7,088		$	764
Deferral of revenue		319			658
Recognition of deferred revenue		(6,872	)		(378	)
Balance at end of period	$	535		$	1,044