Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Mar. 27, 2018	Dec. 27, 2017	Dec. 26, 2017
Liabilities
Deferred tax liabilities, net	$ 8,401	$ 5,002	$ 5,301
Other liabilities, non-current	45,069	43,289	42,112
Equity
Retained earnings	638,309	601,621	$ 602,499
ASU 2014-09 | Adoption Impact of ASU 2014-09
Liabilities
Deferred tax liabilities, net	(308)	(299)
Other liabilities, non-current	1,217	1,177
Equity
Retained earnings	$ (909)	$ (878)