Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity and Share-Based Compensation - Summary of Stock Option Activity (Detail)

v2.4.0.8
Stockholders' Equity and Share-Based Compensation - Summary of Stock Option Activity (Detail) (USD $)
In Thousands, except Share data, unless otherwise specified
 9 Months Ended
Sep. 27, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Options outstanding, Shares, Beginning 5,320,000
Granted, Shares 840,000
Exercised, Shares (129,000)
Expired, Shares (204,000)
Forfeited, Shares (383,000)
Options outstanding, Shares, Ending 5,444,000
Vested and expected to vest, Shares, Ending balance 4,871,000
Options exercisable, Shares, Ending balance 3,242,000
Options outstanding, Weighted Average Exercise Price, Beginning Balance $ 2.97
Granted - Weighted Average Exercise Price $ 2.32
Exercised - Weighted Average Exercise Price $ 2.06
Expired - Weighted Average Exercise Price $ 7.20
Forfeited - Weighted Average Exercise Price $ 1.80
Options outstanding, Weighted Average Exercise Price, Ending Balance $ 2.81
Vested and expected to vest, Weighted Average Exercise Price, Ending Balance $ 2.91
Options exercisable, Weighted Average Exercise Price, Ending Balance $ 3.36
Options outstanding, Weighted Average Remaining Contractual Term (in years), Ending 6 years 6 months 9 days
Vested and expected to vest, Weighted Average Remaining Contractual Term (in years), Ending 6 years 2 months 15 days
Options exercisable, Weighted Average Remaining Contractual Term (in years), Ending 4 years 9 months 14 days
Options outstanding, Aggregate Intrinsic Value, Ending Balance $ 3,320 [1]
Vested and expected to vest, Aggregate Intrinsic Value, Ending Balance 2,876 [1]
Options exercisable, Aggregate Intrinsic Value, Ending Balance $ 1,592 [1]
[1] These amounts represent the difference between the exercise price and the closing price of U.S. Auto Parts Network, Inc. stock on September 27, 2014 as reported on the NASDAQ National Market, for all options outstanding that have an exercise price currently below the closing price.