(8) Other Long-term Liabilities

Other long-term liabilities consist of the following:

	December 31,
	2016			2015
	(In thousands)
Asset retirement obligations (ARO)	$	—		$	397
Deferred rent		1,125			163
		1,125			560
Current maturities of other long-term liabilities		(154	)		(409	)
Other long-term liabilities, less current maturities	$	971		$	151

As of December 31, 2015, the Company had asset retirement obligations (ARO) of $0.4 million arising from requirements to perform certain asset retirement activities upon the termination of its Northborough, Massachusetts facility lease and upon disposal of certain machinery and equipment.

A summary of ARO activity consists of the following:

	Year Ended December 31,
	2016			2015
	(In thousands)
Balance at beginning of period	$	397		$	1,018
Accretion of discount expense		—			21
Settlement costs		(397	)		(642	)
Balance at end of period	$	—		$	397

During the year ended December 31, 2016, the Company incurred approximately $0.2 million in expenditures in support of completing the restoration of space under the facility lease. This space was vacated and returned to the landlord on July 1, 2016.

On June 29, 2016, the Company executed an agreement to remain at the Northborough, Massachusetts facility through December 31, 2026. As part of the new agreement, the Company’s obligation to restore the remaining space in the Northborough facility was eliminated. The settlement of the remaining reserve balance of approximately $0.2 million was reclassified to other long-term liabilities and will be amortized as a reduction to rent expense over the term of the new lease agreement.