Schedule II - Valuation and Qualifying Accounts and Reserves (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 30, 2018	Dec. 31, 2017	Jan. 01, 2017
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year		$ 7,606	$ 4,448	$ 2,117
Additions charged to costs and expenses		9,964	4,464	2,534
Deductions		8,429	1,306	203
Balance at end of year		9,141	7,606	4,448
Deferred Income Tax Valuation Allowance [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year		4,337	1,618	2,307
Adjustment for federal tax legislation	[1]		2,419
Additions charged to costs and expenses		1,562	877
Deductions credited to expense			577	689
Balance at end of year		$ 5,899	$ 4,337	$ 1,618

[1] In 2017, the Company increased its valuation allowance as a result of the deductibility of certain deferred compensation based on the current interpretation of the Tax Act.