Restructuring Charges

During the quarter ended September 30, 2017, we ceased use of an additional 25,812 square feet of our 108,743 square foot headquarters facility in Waltham, Massachusetts. We recorded a lease obligation charge of $3.1 million. The lease obligation charge comprised of restructuring expense, including sublease income and construction costs, net of deferred rent liabilities of $2.6 million. Additionally, we wrote-off $0.5 million of lease-hold improvements related to the space. These estimates may vary from the sublease agreements ultimately executed, if at all, resulting in an adjustment to the charges. The initial restructuring charge was recorded as restructuring expense in the consolidated statements of operations for the three and nine months ended September 30, 2017. In the first quarter of fiscal 2018, we updated our assumptions, as we had signed a sublease agreement for a portion of the ceased use space and updated our estimates for the expected time period it will take to obtain a subtenant for the remainder of the cease use space. This resulted in an additional $0.5 million of restructuring charges in the first quarter of fiscal 2018. During the three months ended September 29, 2018, we again updated our estimate for the expected time period it will take to obtain a subtenant for the remainder of the cease use space, resulting in an additional $0.1 million of restructuring charges in the third quarter of fiscal 2018.

The following table presents the change in restructuring liability from December 30, 2017 to September 29, 2018 (in thousands):



	September 29, 2018
	Restructuring Liability
Balance as of December 30, 2017	$	3,494
Restructuring charges	187
Change in estimates	331
Other payments	(466		)
Net rent payments	(846		)
Accretion of sublease liability	51
Balance as of September 29, 2018	$	2,751