Share-based Compensation (Restricted Common Shares and Stock Options) (Details) - USD ($) $ / shares in Units, $ in Thousands | 3 Months Ended | 6 Months Ended | |
Jun. 27, 2016 | Jun. 29, 2015 | Jun. 27, 2016 | Jun. 29, 2015 | Dec. 28, 2015 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | |
Common shares reserved for equity incentive awards | 2,116,747 | | 2,116,747 | | |
Restricted Stock | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | |
Aggregate number of shares issued under plan | 562,434 | | 562,434 | | 584,017 |
Restricted common stock, weighted average sale date fair value (in dollars per share) | | | | | |
Unvested, Beginning balance (usd per share) | | | $ 3.11 | | |
Vested (usd per share) | | | 12.22 | | |
Repurchased (usd per share) | | | 2.27 | | |
Unvested, Ending balance (usd per share) | $ 2.77 | | 2.77 | | |
Restricted Stock Grants: | | | | | |
Weighted average grant date fair value per share | $ 7.90 | $ 18.81 | $ 7.90 | $ 18.81 | |
Total fair value of shares granted | $ 119 | $ 90 | $ 119 | $ 90 | |
Total fair value of shares vested | $ 103 | 35 | $ 119 | $ 52 | |
Stock Option | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price | | | $ 11 | | |
Aggregate number of shares issued under plan | 1,213,151 | | 1,213,151 | | 1,076,555 |
Stock options outstanding, weighted average exercise price (in dollars per share) | | | | | |
Outstanding, Beginning balance (usd per share) | | | $ 11.55 | | |
Granted (usd per share) | | | 11.04 | | |
Forfeited (usd per share) | | | 11.44 | | |
Outstanding, Ending balance (usd per share) | $ 11.49 | | 11.49 | | |
Exercisable (usd per share) | $ 11.38 | | $ 11.38 | | |
Stock Option Grants | | | | | |
Weighted Average Remaining Contractual Term, Outstanding | | | 8 years 2 months | | |
Weighted Average Remaining Contractual Term, Exercisable | | | 7 years 11 months | | |
Aggregate Intrinsic Value, Outstanding | $ 0 | | $ 0 | | |
Aggregate Intrinsic Value, Exercisable | $ 0 | | $ 0 | | |
Weighted average grant date fair value per share | $ 3.80 | | $ 3.70 | $ 5.41 | |
Total fair value of awards granted | $ 13 | | $ 642 | $ 1,039 | |
Total fair value of awards vested | 151 | $ 314 | 480 | 324 | |
Total intrinsic value of options exercised | $ 25 | | $ 25 | $ 32 | |
Time Vesting | Restricted Stock | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | 15,000 | | |
Number of shares of restricted common stock, unvested [Roll Forward] | | | | | |
Unvested, Beginning balance (in shares) | | | 49,513 | | |
Vested (in shares) | | | (9,764) | | |
Repurchased (in shares) | | | (15,086) | | |
Unvested, Ending balance (in shares) | 39,663 | | 39,663 | | |
Time Vesting | Stock Option | | | | | |
Number of shares of stock options, outstanding [Roll Forward] | | | | | |
Outstanding, Beginning balance (in shares) | | | 841,956 | | |
Granted (in shares) | | | 173,450 | | |
Forfeited (in shares) | | | (22,213) | | |
Outstanding, Ending balance (in shares) | 966,549 | | 966,549 | | |
Exercisable (in shares) | 506,017 | | 506,017 | | |
Stock options outstanding, weighted average exercise price (in dollars per share) | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period | | | 26,644 | | |
Performance Vesting | Restricted Stock | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | 0 | | |
Number of shares of restricted common stock, unvested [Roll Forward] | | | | | |
Unvested, Beginning balance (in shares) | | | 186,515 | | |
Vested (in shares) | | | 0 | | |
Repurchased (in shares) | | | (18,858) | | |
Unvested, Ending balance (in shares) | 167,657 | | 167,657 | | |
Performance Vesting | Stock Option | | | | | |
Number of shares of stock options, outstanding [Roll Forward] | | | | | |
Outstanding, Beginning balance (in shares) | | | 200,481 | | |
Granted (in shares) | | | 0 | | |
Forfeited (in shares) | | | (14,641) | | |
Outstanding, Ending balance (in shares) | 185,840 | | 185,840 | | |
Exercisable (in shares) | 0 | | 0 | | |
Stock options outstanding, weighted average exercise price (in dollars per share) | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period | | | 0 | | |