Selected Quarterly Financial Data - Summary of Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2018		Sep. 28, 2018		Jun. 29, 2018		Mar. 30, 2018		Dec. 31, 2017		Sep. 29, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Quarterly Financial Data [Abstract]
Revenue	$ 113,655		$ 100,616		$ 99,160		$ 90,127		$ 100,974		$ 92,014		$ 82,315		$ 82,943		$ 403,558	[1]	$ 358,246	[1]	$ 405,911	[1]
Gross profit	60,321	[2]	50,102	[2]	51,603	[2]	47,183	[2]	48,572	[2]	47,025	[2]	33,815	[2]	40,408	[2]	209,209		169,820		200,750
Net loss	$ 3,330	[3],[4],[5]	$ (7,758)	[3],[4],[5]	$ (2,913)	[3],[4],[5]	$ (13,694)	[3],[4],[5]	$ (11,516)	[4],[5]	$ (15,583)	[4],[5]	$ (31,500)	[4],[5]	$ (24,027)	[4],[5]	$ (21,035)		$ (82,955)		$ (72,314)
Basic net income (loss) per share from:
Basic and diluted	$ 0.04		$ (0.09)		$ (0.03)		$ (0.16)		$ (0.14)		$ (0.19)		$ (0.39)		$ (0.30)		$ (0.25)		$ (1.02)		$ (0.93)
Denominator:
Basic	86,846		86,321		85,304		83,912
Diluted	89,028		86,321		85,304		83,912
Basic and diluted									82,014		81,445		80,590		79,810		85,615		80,974		77,705

[1] Revenue is attributed to countries based on the location of the customer.

[2] Gross margin decreased to 49.8% during the third quarter of 2018 compared to 52.0% during the second quarter of 2018 and increased to 53.1% during the fourth quarter primarily as a result of product mix. Gross margin decreased to 41.1% during the second quarter of 2017 compared to 48.7% during the first quarter of 2017, primarily due to lower service margins and higher inventory obsolescence charges for the Company’s legacy broadcast video inventory due to reduced demand, as well as higher inventory obsolescence charge for our older Cable Edge product lines. The factors negatively impacting the gross margin during the second quarter of 2017 were mostly absent during the third quarter of 2017, and together with a more favorable product mix, the gross margin increased to 51.1% during the third quarter of 2017 compared to 41.1% during the second quarter of 2017.

[3] During the fourth quarter of 2018, the Company recorded net income primarily due to higher revenues with stronger gross margins of 53.1% coupled with reduced operating expenses as a result of our vigilant cost management.

[4] During the fourth quarter of 2018, the Company released $1.0 million of valuation allowance associated with one of Company’s foreign subsidiaries. During the third and fourth quarter of 2017, the Company recorded $2.4 million of tax benefit associated with the release of tax reserves for uncertain tax positions as a result of the expiration of statute of limitations and $2.5 million of tax benefits associated with the alternative minimum tax refund related to the TCJA, respectively. These tax benefits were offset by $3.0 million tax expense recorded during the fourth quarter of 2017, related to tax law changes in one of the Company’s foreign subsidiaries.

[5] In 2017, the Company incurred TVN acquisition- and integration-related expenses of $2.2 million, $0.5 million, $0.1 million and $0.1 million during the first through fourth quarter of 2017. These costs consisted of acquisition-related costs which include outside legal, accounting and other professional services as well as integration-related costs which include incremental costs resulting from the TVN acquisition that are not expected to generate future benefits once the integration is fully consummated. These costs are expensed as incurred and the Company did not incur any TVN acquisition- and integration-related expenses in 2018.