Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands		Dec. 28, 2018	Dec. 29, 2017
Assets
Money market securities	[1]	$ 6,213	$ 9,742
Total		145,486	134,696
Liabilities
Deferred compensation plan	[2]	59,349	59,050
Total		59,349	59,050
Fixed income securities
Assets
Fixed income available for sale securities	[3]	81,495	71,604
Fixed income trading securities held in deferred compensation plan	[4]	18,618	13,686
Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	39,160	39,664
Fair Value, Inputs, Level 1
Assets
Money market securities	[1]	6,213	9,742
Total		63,991	63,092
Liabilities
Deferred compensation plan	[2]	59,349	59,050
Total		59,349	59,050
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]	18,618	13,686
Fair Value, Inputs, Level 1 | Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	39,160	39,664
Fair Value, Inputs, Level 2
Assets
Money market securities	[1]	0	0
Total		81,495	71,604
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]	81,495	71,604
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 consolidated balance sheet.

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

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

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