Deferred Costs

3 Months Ended

Mar. 31, 2020

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Deferred Costs

Deferred Costs

Changes in the balance of total deferred commissions and total deferred professional service costs during the three months ended March 31, 2020 are as follows (in thousands):

	As of December 31, 2019				Expense recognized		As of March 31, 2020
			Additions
Deferred commissions	$	14,718	$	318	$	(2,383)	$	12,653
Deferred professional service costs	6,711		434		(925)		6,220
Total deferred commissions and professional service costs	$	21,429	$	752	$	(3,308)	$	18,873

 These costs are reviewed for impairment quarterly. Impairment charges were $1.1 million for the three months ended March 31, 2020. Impairment charges for the three months ended March 31, 2019 were immaterial.