RESTRUCTURING ACCRUAL (Tables)

12 Months Ended

Dec. 31, 2017

Restructuring and Related Activities [Abstract]

Summary of restructuring accrual activity

Summaries of the Taqua Restructuring Initiative accrual activity for the years ended December 31, 2017 and 2016 are as follows (in thousands):

Year ended December 31, 2017	Balance at January 1, 2017		Initiatives charged to expense		Adjustments for changes in estimate			Cash payments			Balance at December 31, 2017
Severance	$	384	$	245	$	(49	)	$	(580	)	$	—
Facilities	218		508		—			(361		)	365
	$	602	$	753	$	(49	)	$	(941	)	$	365

Year ended December 31, 2016	Balance at January 1, 2016		Initiatives charged to expense		Adjustments for changes in estimate		Cash payments			Balance at December 31, 2016
Severance	$	—	$	971	$	—	$	(587	)	$	384
Facilities	—		218		—		—			218
	$	—	$	1,189	$	—	$	(587	)	$	602

A summary of the Merger Restructuring Initiative accrual activity for the year ended December 31, 2017 is as follows (in thousands):

Year ended December 31, 2017	Balance at January 1, 2017		Initiatives charged to expense		Adjustments for changes in estimate		Cash payments			Balance at December 31, 2017
Severance	$	—	$	8,508	$	—	$	(913	)	$	7,595

Summaries of the 2016 Restructuring Initiative accrual activity for the years ended December 31, 2017 and 2016 are as follows (in thousands):

Year ended December 31, 2017	Balance at January 1, 2017		Initiatives charged to expense		Adjustments for changes in estimate			Cash payments			Balance at December 31, 2017
Severance	$	497	$	405	$	(26	)	$	(876	)	$	—
Facilities	—		126		—			(31		)	95
	$	497	$	531	$	(26	)	$	(907	)	$	95

Year ended December 31, 2016	Balance at January 1, 2016		Initiatives charged to expense		Adjustments for changes in estimate		Cash payments			Balance at December 31, 2016
Severance	$	—	$	1,484	$	—	$	(987	)	$	497

Summaries of the 2015 Restructuring Initiative accrual for the years ended December 31, 2017 and 2016 are as follows (in thousands):

Year ended December 31, 2017	Balance at January 1, 2017		Initiatives charged to expense		Adjustments for changes in estimate		Cash payments			Balance at December 31, 2017
Severance	$	168	$	—	$	—	$	(168	)	$	—

Year ended December 31, 2016	Balance at January 1, 2016		Initiatives charged to expense		Adjustments for changes in estimate		Cash payments			Balance at December 31, 2016
Severance	$	749	$	—	$	67	$	(648	)	$	168

A summary of the GENBAND Restructuring Initiative accrual activity for the year ended December 31, 2017 is as follows (in thousands):

Year ended December 31, 2017	Balance at January 1, 2017		Liability assumed in connection with Merger		Initiatives charged to expense		Adjustments for changes in estimate			Cash payments			Balance at December 31, 2017
Severance	$	—	$	3,663	$	—	$	(158	)	$	(1,589	)	$	1,916
Facilities	—		431		—		(123		)	(103		)	205
	$	—	$	4,094	$	—	$	(281	)	$	(1,692	)	$	2,121