LONG-TERM DEBT Revolving Credit Facility Narrative (Details) - USD ($) | Jun. 30, 2014 | Sep. 25, 2015 | Dec. 26, 2014 |
Revolving Credit Facility [Line Items] | | | |
Long-term debt | | $ 113,956,000 | $ 201,650,000 |
Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Long-term debt | | $ 86,000,000 | $ 171,994,000 |
Revolving Credit Facility, interest rate description | one-month | | |
Revolving Credit Facility, interest rate at period end | | 1.79% | |
Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility, maximum borrowing capacity | $ 300,000,000 | | |
Revolving Credit Facility, current borrowing capacity | | $ 291,500,000 | |
Revolving Credit Facility, amount outstanding | | 4,500,000 | |
Revolving Credit Facility, utilization threshold | 25.00% | | |
Percent of Eligible Billed Accounts Receivable [Member] [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility Borrowing Limits, Percent of Accounts Receivable | 90.00% | | |
Percent of Eligible Accounts Receivable [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility Borrowing Limits, Percent of Accounts Receivable | 15.00% | | |
Percent of Eligible Unbilled Accounts Receivable [Member] [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility Borrowing Limits, Percent of Accounts Receivable | 85.00% | | |
Liquidation Value of Tacoma Headquarters Office Building [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility Borrowing Limits, Liquidation Value Requirement, Pledged Real Estate | $ 17,400,000 | | |
Revolving Credit Facility Borrowing Limits, Quarterly Reduction, Liquidation Value of Pledged Real Estate | $ 400,000 | | |
Revolving Credit Facility Borrowing Limits, Liquidation Value of Pledged Real Estate | | 15,700,000 | |
Revolving Credit Facility, Liquidity Requirement Component [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility, remaining borrowing capacity | | 201,000,000 | |
Revolving Credit Facility, cash and cash equivalents under control agreements | | 24,600,000 | |
Revolving Credit Facility, total liquidity | | $ 225,600,000 | |
London Interbank Offered Rate (LIBOR) [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility, additional base rate | 1.00% | 1.50% | |
Letters of Credit, additional basis rate | 0.125% | | |
Base rate [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility, additional base rate | 0.50% | 0.50% | |
Minimum [Member] | Revolving Credit Facility, Liquidity Requirement Component [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility, liquidity requirement | $ 37,500,000 | | |
Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Debt Instrument, basis spread on variable rate | 1.25% | | |
Minimum [Member] | Base rate [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Debt Instrument, basis spread on variable rate | 0.25% | | |
Maximum | London Interbank Offered Rate (LIBOR) [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Debt Instrument, basis spread on variable rate | 2.00% | | |
Maximum | Base rate [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Debt Instrument, basis spread on variable rate | 1.00% | | |
Less than 25% utilization [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility, unused capacity, commitment fee percentage | 0.375% | | |
Greater than or equal to 25% utilization [Member] | Bank of America, N.A. and Wells Fargo Capital Finance, LLC [Member] | Revolving Credit Facility [Member] | | | |
Revolving Credit Facility [Line Items] | | | |
Revolving Credit Facility, unused capacity, commitment fee percentage | 0.25% | | |