Winfrey Transaction - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands			3 Months Ended	12 Months Ended
	Oct. 19, 2015	Oct. 18, 2015	Jan. 02, 2016	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Aggregate purchase price						$ 41,475
Options exercisable price per share				$ 10.60
Stock option expense			$ 12,759
Share based compensation ,dividend yield	0.00%			0.00%	0.00%	0.00%
Share based compensation ,volatility	63.88%
Share based compensation ,risk free rate	1.36%			2.17%
Option
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stocks to be purchased through options	3,513
Options exercisable price per share	$ 6.97
Prior To Fourth Anniversary
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of options shares to be transferred	60.00%
Prior To Fifth Anniversary
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of options shares to be transferred	80.00%
Prior To Second Anniversary
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of options shares to be transferred	20.00%
Prior To Third Anniversary
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of options shares to be transferred	40.00%
Strategic Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Initial term of agreement		5 years
Additional renewal terms		1 year
Share Purchase Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Purchased shares	6,362
Purchased shares, price per share	$ 6.79
Aggregate purchase price	$ 43,199
Fees related to share issuance	2,315
Fees related to share issuance, reduction of equity	$ 1,700
Share transfer restriction period	2 years
Minimum percentage of voting power transfer for change of control	50.00%
Share Purchase Agreement | Prior To Third Anniversary | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of shares transferable	15.00%
Share Purchase Agreement | Prior To Fourth Anniversary | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of shares transferable	30.00%
Share Purchase Agreement | Prior To Fifth Anniversary | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of shares transferable	60.00%
Share Purchase Agreement | Right of first offer, the "Securities Act" | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of Company's issued and outstanding Common Stock proposed for transfer	1.00%
Share Purchase Agreement | Right of first refusal, Competitor of the Company | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of Company's issued and outstanding Common Stock proposed for transfer	1.00%
Share Purchase Agreement | Right of first refusal | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Percentage of Company's issued and outstanding Common Stock proposed for transfer	5.00%