SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2017

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Schedule of changes in accumulated other comprehensive income (loss), by component

Changes in accumulated other comprehensive income (loss), by component, were as follows (in thousands):

	Projected
	Pension
	Benefit		Translation		Short Term
	Obligation		Adjustment		Investment		Total
Balance at December 31, 2014	$	(2,672)	$	(249)	$	—	$	(2,921)
Adjust funded status of pension plan, net of tax of $0.7 million		(809)		—		—		(809)
Foreign currency translation adjustment		—		26		—		26
Balance at December 31, 2015		(3,481)		(223)		—		(3,704)
Adjust funded status of pension plan, net of tax of $0.7 million		5,251		—		—		5,251
Foreign currency translation adjustment		—		(687)		—		(687)
Unrealized gain on marketable securities		—		—		868		868
Balance at December 31, 2016		1,770		(910)		868		1,728
Adjust funded status of pension plan, net of tax of $0.7 million		1,357		—		—		1,357
Foreign currency translation adjustment		—		1,265		—		1,265
Reclassifications of gains on sale of marketable securities to net income		—		—		(1,044)		(1,044)
Unrealized gain on marketable securities		—		—		440		440
Balance at December 31, 2017	$	3,127	$	355	$	264	$	3,746

Schedule of reclassification from accumulated other comprehensive income

Amounts reclassified from accumulated other comprehensive income to net income were as follows (in thousands):

		2017		2016		2015
Pension and other postretirement benefit plans	$	716	$	1,300	$	200
Realized gains on marketable securities		(1,044)		—		—
Total	$	(328)	$	1,300	$	200

Schedule of percentage of revenues generated from a single customer that exceeds 10% of the Company's consolidated revenue

Customer	2017		2016		2015
Verizon	10	%	12	%	19	%
AT&T	13	%	14	%	17	%

Schedule of percentage of accounts receivable, from customers that exceed 10% of the Company's consolidated accounts receivable, net of allowances

Customer	2017		2016
AT&T	18	%	17	%
Verizon	—	%	12	%

Schedule of assets and liabilities of the Company measured at fair value on a recurring basis

			December 31, 2017
			Significant Other
	Quoted Prices in		Observable
	Active Markets		Inputs
Description	(Level 1)		(Level 2)		Total
Certificates of deposit	$	—	$	391	$	391
Money market funds		2,894		—		2,894
Short term investments		555		6,521		7,076
Commercial paper		—		49,954		49,954
Interest rate swap		—		52		52
Total assets and liabilities measured at fair value	$	3,449	$	56,918	$	60,367

	December 31, 2016
			Significant Other
	Quoted Prices in		Observable
	Active Markets		Inputs
Description	(Level 1)		(Level 2)		Total
Certificates of deposit	$	—	$	391	$	391
Money market funds		29,027		—		29,027
Short term investments		1,751		7,486		9,237
Commercial paper		—		29,981		29,981
Total assets measured at fair value	$	30,778	$	37,858	$	68,636

Schedule of reconciliation from basic to diluted weighted average common shares outstanding

The reconciliation from basic to diluted weighted average shares of Common Stock outstanding is as follows (in thousands):

	Year ended December 31,
	2017	2016	2015
Basic weighted-average shares of common stock outstanding	16,138	16,131	16,022
Stock options	72	96	120
Diluted weighted-average shares of common stock outstanding	16,210	16,227	16,142

Schedule of anti-dilutive potential shares that were excluded from the computation of diluted weighted average shares outstanding

The following notes the number of potential shares of common stock not included in the above calculation because the effects of such were anti‑dilutive (in thousands of shares):

	For the Year Ended
	December 31,
	2017	2016	2015
Stock options	7	5	2
Total	7	5	2