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, 2019		Sep. 27, 2019		Jun. 28, 2019		Mar. 29, 2019		Dec. 31, 2018		Sep. 28, 2018		Jun. 29, 2018		Mar. 30, 2018		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Quarterly Financial Data [Abstract]
Revenue	$ 122,178		$ 115,725		$ 84,865		$ 80,106		$ 113,655		$ 100,616		$ 99,160		$ 90,127		$ 402,874	[1]	$ 403,558	[1]	$ 358,246	[1]
Gross profit	61,695	[2]	75,540	[2]	43,928	[2]	41,849	[2]	60,321	[2]	50,102	[2]	51,603	[2]	47,183	[2]	223,012		209,209		169,820
Net income (loss)	$ 5,570		$ 11,657		$ (11,845)		$ (11,306)		$ 3,330	[3],[4]	$ (7,758)	[3],[4]	$ (2,913)	[3],[4]	$ (13,694)	[3],[4]	$ (5,924)		$ (21,035)		$ (82,955)
Net loss per share, Basic and diluted
Earnings Per Share, Basic	$ 0.06		$ 0.13		$ (0.13)		$ (0.13)
Earnings Per Share, Diluted	$ 0.06		$ 0.12		$ (0.13)		$ (0.13)
Denominator:
Basic and diluted									$ 0.04		$ (0.09)		$ (0.03)		$ (0.16)		$ (0.07)		$ (0.25)		$ (1.02)
Basic	91,124		89,964		88,931		88,165		86,846		86,321		85,304		83,912
Diluted	97,499		97,596		88,931		88,165		89,028		86,321		85,304		83,912

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

[2] Gross margin in the first, second and fourth quarter of fiscal 2019 was 52.2%, 51.8% and 50.5%. The movement in gross margin in these quarters was primarily due to product mix. Gross margin increased to 65.3% in the third quarter of 2019 primarily due to the recognition of $37.5 million in software license revenue from the Comcast CableOS software license agreement during the third quarter of fiscal 2019. 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.

[3] During the fourth quarter of 2019, the Company recorded a one-time benefit of approximately $2.0 million due to changes in the Company's global tax structure. In addition, the Company recorded a one-time benefit of approximately $0.8 million due to a valuation allowance release for one of its foreign subsidiaries due to changes in forecasted taxable income resulting from the Company receiving a favorable tax ruling during the first quarter of 2019. During the fourth quarter of 2018, the Company released $1.0 million of valuation allowance associated with one of Company’s foreign subsidiaries.

[4] During the third and the fourth quarter of 2019, the Company recorded net income primarily due to growing success of our Cable OS solution and with stronger gross margins due to increase in revenue from Software. 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.