Sources of Revenue and Other Information by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Meeting Fees									$ 664,957	$ 605,332	$ 587,801
Online Subscription Revenues									416,722	343,789	349,567
In-meeting product sales									137,855	125,508	127,291
Licensing, franchise royalties and other									87,377	90,273	99,760
Net revenue	$ 312,488	$ 323,687	$ 341,673	$ 329,063	$ 267,412	$ 280,819	$ 309,761	$ 306,910	1,306,911	1,164,902	1,164,419
Long-lived assets	47,978				49,574				47,978	49,574	58,186
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue									846,249	743,668	700,972
Long-lived assets	42,114				43,714				42,114	43,714	51,103
Canada
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue									64,100	55,159	54,277
Long-lived assets	2,563				2,730				2,563	2,730	2,757
United Kingdom
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue									99,989	100,808	124,773
Long-lived assets	1,920				1,899				1,920	1,899	2,938
Continental Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue									239,223	210,590	229,147
Long-lived assets	642				716				642	716	614
Other
Revenues From External Customers And Long Lived Assets [Line Items]
Net revenue									57,350	54,677	55,250
Long-lived assets	$ 739				$ 515				$ 739	$ 515	$ 774