Acquisition - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 27, 2016	Mar. 11, 2015	Dec. 30, 2017	Dec. 31, 2016
Business Acquisition
Business acquisition, purchase price allocation, goodwill			$ 156,281	$ 166,138
Weight Watchers of Greater Miami, Inc.
Business Acquisition
Business acquisition, purchase price allocation, net purchase price	$ 3,250
Business acquisition, net purchase price	2,898
Business acquisition, cash acquired	300
Business acquisition, assumed net liabilities	52
Business acquisition, purchase price allocation, goodwill	2,945
Weilos
Business Acquisition
Business acquisition, purchase price allocation, net purchase price		$ 6,674
Business acquisition, net purchase price		2,775
Business acquisition, assumed net liabilities		975
Business acquisition, purchase price allocation, goodwill		5,588
Business acquisition, purchase price allocation, finite lived intangible assets		1,741
Business acquisition, purchase price allocation, common stock issued		2,810
Business acquisition, purchase price allocation, restricted stock issued		114
Business acquisition, purchase price allocation, fixed assets		24
Business acquisition, purchase price allocation, deferred tax liabilities		679
Restricted shares issued to key employees		$ 908
Customer Relationships | Weight Watchers of Greater Miami, Inc.
Business Acquisition
Business acquisition, purchase price allocation, finite lived intangible assets	191
Franchise Rights | Weight Watchers of Greater Miami, Inc.
Business Acquisition
Business acquisition, purchase price allocation, indefinite lived intangible assets	$ 114