Leases - Schedule of Finance and Operating Lease Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 30, 2018
Finance Lease Liabilities, Payments, Due [Abstract]
Finance leases, 2019	$ 1,892
Finance leases, 2020	2,593
Finance leases, 2021	1,669
Finance leases, 2022	1,220
Finance leases, 2023	495
Finance leases, total lease payments	$ 7,869
Weighted-average remaining lease term—finance leases	3 years 4 months 24 days
Weighted-average discount rate—finance leases	5.80%
Present values	$ 7,169
Current portion of finance lease liabilities	2,228	$ 2,322
Finance lease liabilities, less current portion	4,941	$ 4,823
Lease liabilities - total	7,169
Difference between undiscounted and discounted cash flows	700
Operating Lease Liabilities, Payments Due [Abstract]
Operating leases, 2019	57,032
Operating leases, 2020	77,263
Operating leases, 2021	54,720
Operating leases, 2022	42,420
Operating leases, 2023	28,962
Operating leases, thereafter	57,434
Operating leases, total lease payments	$ 317,831
Weighted-average remaining lease term—operating leases	5 years 3 months 18 days
Weighted-average discount rate—operating leases	6.50%
Operating lease, liability	$ 266,199
Current portion of operating lease liabilities	60,708
Operating lease liabilities, less current portion	205,491
Lease liabilities - total	266,199
Difference between undiscounted and discounted cash flows	$ 51,632