Unaudited Quarterly Financial Information (Details) - USD ($)	3 Months Ended																12 Months Ended
	Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Income (Loss) [Abstract]
Revenue	$ 49,830,000		$ 45,076,000		$ 37,796,000		$ 34,670,000		$ 52,918,000		$ 41,593,000		$ 46,074,000		$ 46,001,000		$ 167,372,000	$ 186,586,000	$ 193,534,000
Gross profit	14,250,000		14,256,000		12,153,000		10,303,000		18,503,000		15,480,000		16,597,000		17,863,000		50,962,000	68,443,000	75,290,000
Net income (loss)	$ (2,167,000)	[1]	$ (1,449,000)	[2]	$ (9,376,000)	[3]	$ (9,341,000)	[4]	$ (2,118,000)	[5]	$ (3,292,000)	[6]	$ (1,181,000)	[7]	$ 319,000	[8]	(22,333,000)	(6,272,000)	6,340,000
Basic and diluted net loss per share	$ (0.07)		$ (0.05)		$ (0.31)		$ (0.32)		$ (0.07)		$ (0.11)		$ (0.04)		$ 0.01
Stock-based compensation expense	$ 1,000,000		$ 1,100,000		$ 1,000,000		$ 839,000		$ 1,000,000		$ 1,000,000		$ 1,200,000		$ 755,000		3,946,000	3,967,000	3,980,000
Deferred Tax Liabilities, Undistributed Foreign Earnings	$ 3,675,000								1,590,000								3,675,000	1,590,000
Restructuring and exit costs					$ 2,300,000												2,512,000	$ 0	0
Repatriation of Foreign Earnings, Amount									$ 1,590,000								$ 2,085,000		$ 0

[1] Includes a non-cash expense for stock-based compensation of $1.0 million.

[2] Includes a non-cash expense for stock-based compensation of $1.1 million.

[3] Includes restructuring costs of $2.3 million, a non-cash deferred tax expense of $2.1 million in connection with the probable repatriation of a portion of the unremitted earnings of a foreign subsidiary and a non-cash expense for stock-based compensation of $1.0 million.

[4] Includes a non-cash expense for stock-based compensation of $839,000.

[5] Includes non-cash deferred tax expense of $1.6 million in connection with the probable repatriation of a portion of the unremitted earnings of a foreign subsidiary and a non-cash expense for stock-based compensation of $1.0 million.

[6] Includes a non-cash expense for stock-based compensation of $1.0 million.

[7] Includes a non-cash expense for stock-based compensation of $1.2 million

[8] Includes a non-cash expense for stock-based compensation of $755,000.