Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands		Mar. 29, 2019	Dec. 28, 2018
Assets
Money market securities	[1]	$ 770	$ 6,213
Total		165,194	145,486
Liabilities
Deferred compensation plan	[2]	73,119	59,349
Total		73,119	59,349
Fixed income securities
Assets
Fixed income available-for-sale securities	[3]	92,680	81,495
Fixed income trading securities held in deferred compensation plan	[4]	25,504	18,618
Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	46,240	39,160
Fair Value, Inputs, Level 1
Assets
Money market securities	[1]	770	6,213
Total		72,514	63,991
Liabilities
Deferred compensation plan	[2]	73,119	59,349
Total		73,119	59,349
Fair Value, Inputs, Level 1 | Fixed income securities
Assets
Fixed income available-for-sale securities	[3]	0	0
Fixed income trading securities held in deferred compensation plan	[4]	25,504	18,618
Fair Value, Inputs, Level 1 | Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	46,240	39,160
Fair Value, Inputs, Level 2
Assets
Money market securities	[1]	0	0
Total		92,680	81,495
Liabilities
Deferred compensation plan	[2]	0	0
Total		0	0
Fair Value, Inputs, Level 2 | Fixed income securities
Assets
Fixed income available-for-sale securities	[3]	92,680	81,495
Fixed income trading securities held in deferred compensation plan	[4]	0	0
Fair Value, Inputs, Level 2 | Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	0	0
Fair Value, Inputs, Level 3
Assets
Money market securities	[1]	0	0
Total		0	0
Liabilities
Deferred compensation plan	[2]	0	0
Total		0	0
Fair Value, Inputs, Level 3 | Fixed income securities
Assets
Fixed income available-for-sale securities	[3]	0	0
Fixed income trading securities held in deferred compensation plan	[4]	0	0
Fair Value, Inputs, Level 3 | Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	$ 0	$ 0

[1] Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet.

[2] Included in accrued payroll and employee benefits and deferred compensation plan liabilities on the Company’s unaudited condensed consolidated balance sheet.

[3] Included in short-term investments on the Company’s unaudited condensed consolidated balance sheet.

[4] Included in prepaid expenses and other current assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet.