Description of Business and Summary of Significant Accounting Policies - Additional Information (Details) |
3 Months Ended | |
|---|---|---|
|
Apr. 01, 2016
USD ($)
segment
|
Mar. 27, 2015
USD ($)
|
|
| Accounting Policies [Line Items] | ||
| Document period end date | Apr. 01, 2016 | |
| Number of reportable segments | segment | 1 | |
| Revenue | $ 310,682,000 | $ 260,920,000 |
| Government Contracts Concentration Risk | Sales Revenue, Net | U.S. Army | ||
| Accounting Policies [Line Items] | ||
| Concentration risk, percentage | 69.00% | 70.00% |
| Government Contracts Concentration Risk | Sales Revenue, Net | U.S. Army | Four Largest Contracts | ||
| Accounting Policies [Line Items] | ||
| Concentration risk, percentage | 85.00% | 90.50% |
| Revenue | $ 214,600,000 | $ 183,300,000 |
| High Desert Support Services (HDSS) | ||
| Accounting Policies [Line Items] | ||
| Equity method investment, percentage income or loss | 40.00% | |
| Distributions from equity method investment | $ 0 | $ 0 |
| Other Noncurrent Assets | High Desert Support Services (HDSS) | ||
| Accounting Policies [Line Items] | ||
| Equity method investments | $ 1,300,000 | |