15. RESTRUCTURING

In December 2011, the Company restructured its operations by reducing its workforce by 35 employees. In November 2012, the Company notified 21 Bothell, Washington based employees that they would be terminated as part of the corporate headquarters relocation to Cambridge, Massachusetts. Terminated employees were given various incentives to remain through a transition period which was completed in 2013. During 2013, the transition period was extended for an employee through the second quarter of 2014. As of June 30, 2014, the program was completed.

The following table summarizes changes in the liability and the balance at year end related to these restructuring plans for each of the periods indicated.


	For the Year Ended December 31,
	2014			2013			2012
	(in thousands)
Balance at beginning of the period	$	44		$	185		$	828
Restructuring charge		14			764			185
Payments		(58	)		(905	)		(828	)

Balance at ending of the period	$	—		$	44		$	185

The following table summarizes restructuring expense by function for each of the periods indicated.


	For the Year Ended December 31,
	2014		2013		2012
	(in thousands)
Research and development	$	14	$	414	$	69
General and administrative		—		350		116

Total	$	14	$	764	$	185