Restructuring Costs (Tables)

9 Months Ended

Sep. 30, 2019

Restructuring And Related Activities [Abstract]

Summary of Restructuring Costs

The types of charges for restructuring costs for the three and nine months ended September 30, 2019 and September 30, 2018 were (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
Severance and benefits	$	253	$	—	$	1,254	$	—
Asset impairment charge (see Note 11)		—		—		375		—
Total	$	253	$	—	$	1,629	$	—

Summary of Activity and Estimated Timing of Future Payouts for Accrued Restructuring Costs

The following tables show the activity and estimated timing of future payouts for accrued restructuring costs (in thousand):

	Three Months Ended September 30,
	2019			2018
Balance as of June 30, 2019	$	661		$	—
Restructuring costs		253			—
Adjustments of prior estimates		—			—
Non-cash asset impairment charge		—			—
Cash payments		(442	)		—
Balance as of September 30, 2019	$	472		$	—
	Nine Months Ended September 30,
	2019			2018
Balance as of December 31, 2018	$	—		$	—
Restructuring costs		1,629			—
Adjustments of prior estimates		—			—
Non-cash asset impairment charge		(375	)		—
Cash payments		(782	)		—
Balance as of September 30, 2019	$	472		$	—
	As of September 30,
Estimated timing of future payments:	2019			2018
Remainder of 2019	$	310		$	—
2020		162			—
Total stock-based compensation expense	$	472		$	—