Components of and Changes in Accumulated Other Comprehensive Income, Net of Related Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 466,237	$ 488,261	$ 454,481
Other comprehensive income (loss)	399	(2,303)	(1,173)
Ending Balance	542,557	466,237	488,261
Unrealized Holding Gains (Losses) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(94)	105	244
Other comprehensive income (loss)	23	(199)	(139)
Ending Balance	(71)	(94)	105
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(3,394)	(1,290)	(256)
Other comprehensive income (loss)	376	(2,104)	(1,034)
Ending Balance	(3,018)	(3,394)	(1,290)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(3,488)	(1,185)	(12)
Other comprehensive income (loss)	399	(2,303)	(1,173)
Ending Balance	$ (3,089)	$ (3,488)	$ (1,185)