Update to Significant Accounting Policies - Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 27, 2020	Dec. 29, 2019
Carrying Value
Measurement of financial assets and liabilities at fair value on a recurring basis
Cash surrender value of life insurance policies	$ 33,953	$ 33,220
Interest rate swap liabilities	15,334	6,168
Measured on Recurring Basis | Level 1
Measurement of financial assets and liabilities at fair value on a recurring basis
Cash surrender value of life insurance policies	33,953	33,220
Measured on Recurring Basis | Level 2
Measurement of financial assets and liabilities at fair value on a recurring basis
Interest rate swap liabilities	$ 15,334	$ 6,168