Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands		Jun. 29, 2018	Dec. 29, 2017
Assets
Money market securities	[1]	$ 6,267	$ 9,742
Total		140,288	134,696
Liabilities
Deferred compensation plan	[2]	62,196	59,050
Total		62,196	59,050
Fixed income securities
Assets
Fixed income available-for-sale securities	[3]	75,534	71,604
Fixed income trading securities held in deferred compensation plan	[4]	16,419	13,686
Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	42,068	39,664
Fair Value, Inputs, Level 1
Assets
Money market securities	[1]	6,267	9,742
Total		64,754	63,092
Liabilities
Deferred compensation plan	[2]	62,196	59,050
Total		62,196	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]	16,419	13,686
Fair Value, Inputs, Level 1 | Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	42,068	39,664
Fair Value, Inputs, Level 2
Assets
Money market securities	[1]	0	0
Total		75,534	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]	75,534	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 unaudited condensed consolidated balance sheet.

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