Leases - ROU assets and lease liabilities (Detail) - USD ($) $ in Thousands	Dec. 25, 2021	Dec. 26, 2020
Right-of-use assets
Operating lease assets	$ 52,774	$ 58,483
Finance lease assets	$ 3,014	$ 4,035
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant and Equipment, Net	Property, Plant and Equipment, Net
Current
Operating lease liabilities	$ 7,634	$ 8,232
Finance lease liabilities	$ 1,598	$ 1,453
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued Liabilities and Other Liabilities	Accrued Liabilities and Other Liabilities
Non-current
Operating lease liabilities	$ 53,849	$ 59,171
Finance lease liabilities	$ 1,459	$ 2,631
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent