Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Jan. 01, 2016
Assets
Money market securities	[1]	$ 28,901	$ 10,530
Total		127,442	99,312
Liabilities
Deferred compensation plan	[2]	51,845	46,740
Total		51,845	46,740
Fixed income securities
Assets
Fixed income available-for-sale securities	[3]	51,993	45,842
Fixed income trading securities held in deferred compensation plan	[4]	12,020	9,295
Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	34,528	33,645
Fair Value, Inputs, Level 1
Assets
Money market securities	[1]	28,901	10,530
Total		75,449	53,470
Liabilities
Deferred compensation plan	[2]	51,845	46,740
Total		51,845	46,740
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]	12,020	9,295
Fair Value, Inputs, Level 1 | Equity securities
Assets
Equity trading securities held in deferred compensation plan	[4]	34,528	33,645
Fair Value, Inputs, Level 2
Assets
Money market securities	[1]	0	0
Total		51,993	45,842
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]	51,993	45,842
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.