Equity Compensation - Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 25, 2016	Dec. 27, 2015
Number of Options
Number of Options, Outstanding (in shares)	1,316,000
Number of Options, Granted (in shares)	315,000	403,000	330,000
Number of Options, Exercised (in shares)	(147,000)	(478,000)	(441,000)
Number of Options, Cancelled (in shares)	(32,000)
Number of Options, Outstanding (in shares)	1,452,000	1,316,000
Number of Options, Exercisable (in shares)	800,000
Weighted Average Exercise Price
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 46.58
Weighted Average Exercise Price, Granted (in dollars per share)	78.59
Weighted Average Exercise Price, Exercised (in dollars per share)	42.71
Weighted Average Exercise Price, Cancelled (in dollars per share)	68.30
Weighted Average Exercise Price, Outstanding (in dollars per share)	53.43	$ 46.58
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 40.72
Options, Additional Disclosures
Weighted Average Remaining Contractual Term, Outstanding	7 years 26 days
Weighted Average Remaining Contractual Term, Exercisable	5 years 10 months 21 days
Aggregate Intrinsic Value, Outstanding	$ 13,901
Aggregate Intrinsic Value, Exercisable	$ 13,901