Commitments and Contingencies (Details) - USD ($) $ in Thousands |
9 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|
Sep. 28, 2017 |
Sep. 29, 2016 |
Dec. 29, 2016 |
Dec. 31, 2015 |
Dec. 25, 2014 |
|
| Future minimum lease payments under non cancelable operating leases | |||||
| Thirteen weeks ended December 28, 2017 | $ 18,100 | ||||
| 2018 | 81,967 | $ 71,913 | |||
| 2019 | 92,825 | 73,580 | |||
| 2020 | 91,135 | 71,598 | |||
| 2021 | 87,128 | 67,875 | |||
| Thereafter | 564,361 | 369,231 | |||
| Total minimum lease payments | 935,516 | 717,537 | |||
| Lease expense | $ 51,956 | $ 39,211 | $ 53,899 | $ 41,756 | $ 29,774 |