Weighted-Average Fair Value of Stock Options and Employee Stock Purchase Rights using Weighted-Average Assumptions (Detail) - $ / shares	12 Months Ended
Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Stock Options
Weighted-average assumptions
Weighted-average fair value of grants per share	$ 1.76	$ 2.05	$ 3.15
Expected volatility	43.86%	46.12%	52.12%
Risk free interest rate	0.97%	1.42%	1.39%
Expected term of options (in years)	4 years 3 months 11 days	3 years 11 months 27 days	4 years 4 months 17 days
Dividend yield	0.00%	0.00%	0.00%
Stock Purchase Rights
Weighted-average assumptions
Weighted-average fair value of grants per share	$ 1.55	$ 2.14	$ 2.08
Expected volatility	39.22%	43.45%	44.00%
Risk free interest rate	0.75%	0.45%	0.11%
Expected term of options (in years)	1 year 10 months 13 days	1 year 4 months 10 days	8 months 9 days
Dividend yield	0.00%	0.00%	0.00%

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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