Fair Value Measurements (Assets) (Details) - USD ($) $ in Thousands | Jun. 29, 2019 | Dec. 29, 2018 |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash and cash equivalents (including money market funds) | $ 28,782 | $ 76,819 |
Fair value, measurements, recurring | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash and cash equivalents (including money market funds) | 28,782 | 76,819 |
Derivative financial instruments | 1,076 | 3,797 |
Deferred stock-based compensation | 8,686 | 7,857 |
Fair value, measurements, recurring | Quoted prices in active markets for identical assets (Level 1) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash and cash equivalents (including money market funds) | 28,782 | 76,819 |
Derivative financial instruments | 0 | 0 |
Deferred stock-based compensation | 0 | 0 |
Fair value, measurements, recurring | Significant other observable inputs (Level 2) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash and cash equivalents (including money market funds) | 0 | 0 |
Derivative financial instruments | 1,076 | 3,797 |
Deferred stock-based compensation | 8,686 | 7,857 |
Fair value, measurements, recurring | Significant unobservable inputs (Level 3) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Cash and cash equivalents (including money market funds) | 0 | 0 |
Derivative financial instruments | 0 | 0 |
Deferred stock-based compensation | 0 | 0 |
Fair value, measurements, recurring | Government securities | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Available-for-sale debt securities | 7,485 | 7,384 |
Fair value, measurements, recurring | Government securities | Quoted prices in active markets for identical assets (Level 1) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Available-for-sale debt securities | 0 | 0 |
Fair value, measurements, recurring | Government securities | Significant other observable inputs (Level 2) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Available-for-sale debt securities | 7,485 | 7,384 |
Fair value, measurements, recurring | Government securities | Significant unobservable inputs (Level 3) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Available-for-sale debt securities | 0 | 0 |
Fair value, measurements, recurring | Corporate Bonds | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Available-for-sale debt securities | 5,436 | 4,620 |
Fair value, measurements, recurring | Corporate Bonds | Quoted prices in active markets for identical assets (Level 1) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Available-for-sale debt securities | 0 | 0 |
Fair value, measurements, recurring | Corporate Bonds | Significant other observable inputs (Level 2) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Available-for-sale debt securities | 5,436 | 4,620 |
Fair value, measurements, recurring | Corporate Bonds | Significant unobservable inputs (Level 3) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Available-for-sale debt securities | 0 | 0 |
Variable Rate Debt Obligation | Fair value, measurements, recurring | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fair value of debt obligations | 186,000 | 150,000 |
Variable Rate Debt Obligation | Fair value, measurements, recurring | Quoted prices in active markets for identical assets (Level 1) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fair value of debt obligations | 0 | 0 |
Variable Rate Debt Obligation | Fair value, measurements, recurring | Significant other observable inputs (Level 2) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fair value of debt obligations | 186,000 | 150,000 |
Variable Rate Debt Obligation | Fair value, measurements, recurring | Significant unobservable inputs (Level 3) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fair value of debt obligations | 0 | 0 |
Fixed Rate Debt Obligation | Fair value, measurements, recurring | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fair value of debt obligations | 100,000 | 100,000 |
Fixed Rate Debt Obligation | Fair value, measurements, recurring | Quoted prices in active markets for identical assets (Level 1) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fair value of debt obligations | 0 | 0 |
Fixed Rate Debt Obligation | Fair value, measurements, recurring | Significant other observable inputs (Level 2) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fair value of debt obligations | 100,000 | 100,000 |
Fixed Rate Debt Obligation | Fair value, measurements, recurring | Significant unobservable inputs (Level 3) | | |
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fair value of debt obligations | $ 0 | $ 0 |