10. Restructuring

We recorded the following net restructuring charges within our consolidated statements of operations (in thousands):

	Three Months Ended					Six Months Ended
	June 30,					June 30,
	2018			2017		2018		2017
Cost of revenue	$	—		$	—	$	27	$	—
Research and development		(109	)		1,265		78		333
General and administrative		509			157		766		244
Total restructuring charges	$	400		$	1,422	$	871	$	577

Restructuring activities, summarized by plan, are presented in the table below (in thousands):

	Q4 2017			Q2 2015			Other
	Restructuring Plan			Restructuring Plan			Restructuring Plans			Total
Restructuring liability – December 31, 2017	$	371		$	14,152		$	7		$	14,530
Restructuring expense and adjustments		770			76			25			871
Cash payments		(756	)		(1,727	)		(32	)		(2,515	)
Restructuring liability – June 30, 2018	$	385		$	12,501		$	—		$	12,886
Cumulative costs to date, as of June 30, 2018	$	2,236		$	34,400		$	2,195		$	38,831
Total costs expected to be incurred, as of June 30, 2018	$	2,252		$	34,400		$	2,195		$	38,847

Q4 2017 Restructuring Plan

During the fourth quarter of 2017, we implemented a restructuring plan which included a reduction in work force to reduce the Company’s long-term cost structure. As a result of ongoing initiatives associated with this restructuring plan, we recorded $0.4 million and $0.8 million of expense during the three and six months ended June 30, 2018, respectively, which is included in operating expenses in our consolidated statement of operations. The $0.4 million restructuring charge for the three months ended June 30, 2018 is comprised of $0.1 million of employee severance costs and $0.3 million of other costs and the $0.8 million restructuring charge for the six months ended June 30, 2018 is comprised of $0.3 million of employee severance costs and $0.5 million of other costs. The remaining costs are expected to be paid out within the next quarter.

Q2 2015 Restructuring Plan

During the second quarter of 2015, we implemented a restructuring plan which included a reduction in work force to reduce the Company’s long-term cost structure. As a result of ongoing initiatives associated with this restructuring plan, we recorded $0.1 million of other costs during the three and six months ended June 30, 2018, which is included in operating expenses in our consolidated statement of operations. The remaining liability is expected to be paid out over the next 3.9 years.