11. RESTRUCTURING

In March 2016, the Company announced a long-term plan (“Corvallis plan”) to consolidate all of the Company’s operations to Massachusetts as part of a strategic plan to increase operational efficiency. As part of the consolidation, research activities and some employees transitioned to the Company’s facilities in Andover and Cambridge, Massachusetts. As of December 31, 2017, the relocations and terminations were completed.

The second floor and the first floor of the Corvallis facility were vacated and closed and made available for sub-leasing in December 2016 and April 2017, respectively. Using a discounted cash flow methodology and based on monthly rent payments as well as estimated sublease income, the Company recognized a total of approximately $1.5 million and $2.3 million, in restructuring expenses for the second and the first floor, respectively. As of March 31, 2018, the Company continues to be obligated to make $4.5 million of minimum lease payments and certain other contractual maintenance costs for the whole facility.

The following table summarizes the restructuring reserve for the periods indicated:

	For the Three Months Ended March 31, 2018			For the Year Ended December 31, 2017
	(in thousands)
Restructuring reserve beginning balance	$	2,933		$	1,588
Restructuring expenses incurred during the period		—			3,020
Amounts paid during the period		(355	)		(1,675	)
Restructuring reserve ending balance	$	2,578		$	2,933