Exponent (EXPO) 10-Q 7 Nov 14 2014 Q3 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	9 Months Ended
	Oct. 03, 2014	Oct. 31, 2014
Document Information [Line Items]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	3-Oct-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
Entity Registrant Name	'EXPONENT INC	'
Entity Central Index Key	'0000851520	'
Current Fiscal Year End Date	'--01-02	'
Entity Filer Category	'Accelerated Filer	'
Trading Symbol	'EXPO	'
Entity Common Stock, Shares Outstanding	'	12,866,600

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Oct. 03, 2014	Jan. 03, 2014
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$115,614	$122,948
Short-term investments	26,009	33,171
Accounts receivable, net of allowance for doubtful accounts of $3,241 and $2,771 at October 3, 2014 and January 3, 2014, respectively	89,089	76,980
Prepaid expenses and other assets	12,630	10,450
Deferred income taxes	11,141	8,135
Total current assets	254,483	251,684
Property, equipment and leasehold improvements, net	28,812	28,721
Goodwill	8,607	8,607
Deferred income taxes	24,234	21,102
Deferred compensation plan assets	34,634	33,501
Other assets	1,286	551
Total assets	352,056	344,166
Current liabilities:	'	'
Accounts payable and accrued liabilities	11,011	8,442
Accrued payroll and employee benefits	54,496	56,934
Deferred revenues	5,848	6,771
Total current liabilities	71,355	72,147
Other liabilities	1,613	1,181
Deferred compensation	36,384	33,447
Deferred rent	2,162	2,332
Total liabilities	111,514	109,107
Stockholders' equity:	'	'
Common stock, $0.001 par value; 100,000 shares authorized; 16,427 shares issued at October 3, 2014 and January 3, 2014	16	16
Additional paid-in capital	158,909	141,250
Accumulated other comprehensive income	'	'
Investment securities, available for sale	19	10
Foreign currency translation adjustments	-372	99
Accumulated Other Comprehensive Income (Loss), Net of Tax, Total	-353	109
Retained earnings	241,074	226,040
Treasury stock, at cost; 3,519 and 3,363 shares held at October 3, 2014 and January 3, 2014, respectively	-159,104	-132,356
Total stockholders' equity	240,542	235,059
Total liabilities and stockholders' equity	$352,056	$344,166

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Oct. 03, 2014	Jan. 03, 2014
In Thousands, except Per Share data, unless otherwise specified
Accounts receivable, allowance for contract losses and doubtful accounts	$3,241	$2,771
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	100,000	100,000
Common stock, shares issued	16,427	16,427
Treasury stock, shares	3,519	3,363

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Oct. 03, 2014	Sep. 27, 2013	Oct. 03, 2014	Sep. 27, 2013
Revenues:	'	'	'	'
Revenues before reimbursements	$74,264	$70,096	$219,562	$211,007
Reimbursements	4,293	5,135	11,531	12,389
Revenues	78,557	75,231	231,093	223,396
Operating expenses:	'	'	'	'
Compensation and related expenses	43,948	44,801	138,855	137,795
Other operating expenses	6,715	6,440	19,482	18,794
Reimbursable expenses	4,293	5,135	11,531	12,389
General and administrative expenses	4,363	3,695	11,809	10,814
Total operating expenses	59,319	60,071	181,677	179,792
Operating income	19,238	15,160	49,416	43,604
Other income (expense), net:	'	'	'	'
Interest income, net	33	14	117	95
Miscellaneous income (expense), net	-896	2,341	2,605	5,592
Total other income (expense), net	-863	2,355	2,722	5,687
Income before income taxes	18,375	17,515	52,138	49,291
Income taxes	7,335	6,421	20,680	19,373
Net income	$11,040	$11,094	$31,458	$29,918
Net income per share:	'	'	'	'
Basic	$0.82	$0.82	$2.33	$2.19
Diluted	$0.80	$0.79	$2.26	$2.13
Shares used in per share computations:	'	'	'	'
Basic	13,469	13,598	13,509	13,638
Diluted	13,824	13,993	13,889	14,047
Cash dividends declared per common share	$0.25	$0.15	$0.75	$0.45

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Oct. 03, 2014	Sep. 27, 2013	Oct. 03, 2014	Sep. 27, 2013
Net income	$11,040	$11,094	$31,458	$29,918
Other comprehensive income (loss):	'	'	'	'
Foreign currency translation adjustments, net of tax	-840	556	-471	119
Unrealized (loss) gain on available for sale investment securities, net of tax	-13	-3	9	-25
Comprehensive income	$10,187	$11,647	$30,996	$30,012

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Oct. 03, 2014	Sep. 27, 2013
Cash flows from operating activities:	'	'
Net income	$31,458	$29,918
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization of property, equipment and leasehold improvements	3,979	3,667
Amortization of premiums and accretion of discounts on short-term investments	660	165
Deferred rent	-170	884
Provision for doubtful accounts	1,234	822
Stock-based compensation	10,585	10,832
Deferred income tax provision	-6,046	-2,770
Excess tax benefit from equity awards	-5,126	-4,064
Changes in operating assets and liabilities:	'	'
Accounts receivable	-13,343	2,362
Prepaid expenses and other assets	-2,877	-3,498
Accounts payable and accrued liabilities	6,314	-521
Accrued payroll and employee benefits	331	-3,469
Deferred revenues	-923	-510
Net cash provided by operating activities	26,076	33,818
Cash flows from investing activities:	'	'
Capital expenditures	-3,906	-4,593
Purchase of short-term investments	-1,067	-11,813
Maturity of short-term investments	7,586	19,190
Net cash provided by investing activities	2,613	2,784
Cash flows from financing activities:	'	'
Excess tax benefit from equity awards	5,126	4,064
Payroll taxes for restricted stock units	-6,356	-6,112
Repurchase of common stock	-26,372	-21,719
Exercise of share-based payment awards	1,811	1,497
Dividends and dividend equivalents paid	-9,842	-5,962
Net cash used in financing activities	-35,633	-28,232
Effect of foreign currency exchange rates on cash and cash equivalents	-390	109
Net (decrease) increase in cash and cash equivalents	-7,334	8,479
Cash and cash equivalents at beginning of period	122,948	113,268
Cash and cash equivalents at end of period	$115,614	$121,747

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Oct. 03, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Note 1: Basis of Presentation
	Exponent, Inc. (referred to as the “Company” or “Exponent”) is an engineering and scientific consulting firm that provides solutions to complex problems. The Company operates on a 52-53 week fiscal year ending on the Friday closest to the last day of December.
	The accompanying unaudited condensed consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission. Accordingly, they do not contain all the information and notes required by accounting principles generally accepted in the United States of America for complete financial statements. In the opinion of management, all adjustments which are necessary for the fair presentation of the condensed consolidated financial statements have been included and all such adjustments are of a normal and recurring nature. The operating results for the three and nine months ended October 3, 2014 are not necessarily representative of the results of future quarterly or annual periods. The following information should be read in conjunction with the audited consolidated financial statements and accompanying notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended January 3, 2014 which was filed with the U.S. Securities and Exchange Commission on February 28, 2014.
	The unaudited condensed consolidated financial statements include the accounts of Exponent, Inc. and its subsidiaries, which are all wholly owned. All intercompany accounts and transactions have been eliminated in consolidation.
	Authorized Capital Stock. In a letter dated May 23, 2006, the Company committed to stockholders to limit its use of authorized capital stock to 40 million common shares, and 2 million preferred shares, unless the approval of the Company’s stockholders is subsequently obtained, such as through a further amendment to the Company’s authorized capital stock.
	Dividend. The Company declared and paid cash dividends per common share during the periods presented as follows:
		Fiscal Year 2014
		Dividends		Amount
		Per Share		(in thousands)
	First Quarter	$	0.25	$	3,262
	Second Quarter	$	0.25		3,270
	Third Quarter	$	0.25		3,262
				$	9,794
		Fiscal Year 2013
		Dividends		Amount
		Per Share		(in thousands)
	First Quarter	$	0.15	$	1,969
	Second Quarter	$	0.15		1,998
	Third Quarter	$	0.15		1,945
	Fourth Quarter	$	0.15		1,965
				$	7,877
	Prior to 2013 the Company had never paid cash dividends on its common stock. On October 22, 2014 the Company’s Board of Directors announced a cash dividend of $0.25 per share of the Company’s common stock, payable December 19, 2014, to stockholders of record as of November 28, 2014. The Company expects to continue paying quarterly dividends in the future, subject to declaration by the Company’s Board of Directors.
	Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the period. Significant items subject to such estimates and assumptions include accounting for revenue recognition and estimating the allowance for doubtful accounts. Actual results could differ from those estimates.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Oct. 03, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Note 2: Fair Value Measurements
	The Company measures certain financial assets and liabilities at fair value on a recurring basis, including available-for-sale fixed income securities, trading fixed income and equity securities held in its deferred compensation plan and the liability associated with its deferred compensation plan. There have been no transfers between fair value measurement levels during the nine months ended October 3, 2014 and September 27, 2013. Any transfers between fair value measurement levels would be recorded on the actual date of the event or change in circumstances that caused the transfer. The fair value of these certain financial assets and liabilities was determined using the following inputs at October 3, 2014:
			Fair Value Measurements at Reporting Date Using
	(In thousands)		Total		Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable
					Identical Assets		(Level 2)		Inputs
					(Level 1)				(Level 3)
	Assets
	Money market
	securities (1)		$	44,246	$	44,246	$	-	$	-
	Fixed income available
	for sale securities (2)			26,009		-		26,009		-
	Fixed income trading
	securities held in deferred
	compensation plan (3)			9,759		9,759		-		-
	Equity trading securities
	held in deferred
	compensation plan (3)			32,339		32,339		-		-
	Total		$	112,353	$	86,344	$	26,009	$	-
	Liabilities
	Deferred compensation
	plan (4)			43,832		43,832		-		-
	Total		$	43,832	$	43,832	$	-	$	-
		-1	Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet.
		-2	Included in short-term investments on the Company’s unaudited condensed consolidated balance sheet.
		-3	Included in prepaid expenses and other assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet.
		-4	Included in accrued payroll and employee benefits and deferred compensation on the Company’s unaudited condensed consolidated balance sheet.
	The fair value of these certain financial assets and liabilities was determined using the following inputs at January 3, 2014:
			Fair Value Measurements at Reporting Date Using
	(In thousands)		Total		Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable
					Identical Assets		(Level 2)		Inputs
					(Level 1)				(Level 3)
	Assets
	Money market
	securities (1)		$	37,099	$	37,099	$	-	$	-
	Fixed income available
	for sale securities (2)			33,171		-		33,171		-
	Fixed income trading
	securities held in deferred
	compensation plan (3)			9,535		9,535		-		-
	Equity trading securities
	held in deferred
	compensation plan (3)			28,444		28,444		-		-
	Total		$	108,249	$	75,078	$	33,171	$	-
	Liabilities
	Deferred compensation
	plan (4)			37,926		37,926		-		-
	Total		$	37,926	$	37,926	$	-	$	-
		-1	Included in cash and cash equivalents on the Company’s consolidated balance sheet.
		-2	Included in short-term investments on the Company’s consolidated balance sheet.
		-3	Included in prepaid expenses and other assets and deferred compensation plan assets on the Company’s consolidated balance sheet.
		-4	Included in accrued payroll and employee benefits and deferred compensation on the Company’s consolidated balance sheet.
	Fixed income available-for-sale securities as of October 3, 2014 and January 3, 2014 represent primarily obligations of state and local government agencies. Fixed income and equity trading securities represent mutual funds held in the Company’s deferred compensation plan. See Note 6 for additional information about the Company’s deferred compensation plan.
	Cash, cash equivalents and short-term investments consisted of the following as of October 3, 2014:
			Amortized		Unrealized		Unrealized		Estimated
	(In thousands)		Cost		Gains		Losses		Fair Value
	Classified as current assets:
	Cash		$	71,368	$	-	$	-	$	71,368
	Cash equivalents:
	Money market securities			44,246		-		-		44,246
	Total cash equivalents			44,246		-		-		44,246
	Total cash and cash equivalents			115,614		-		-		115,614
Short-term investments:
State and municipal bonds			25,977		36		-4		26,009
Total short-term investments			25,977		36		-4		26,009
Total cash, cash equivalents and short-term investments		$	141,591	$	36	$	-4	$	141,623
Cash, cash equivalents and short-term investments consisted of the following as of January 3, 2014:
		Amortized		Unrealized		Unrealized		Estimated
(In thousands)		Cost		Gains		Losses		Fair Value
Classified as current assets:
Cash		$	85,849	$	-	$	-	$	85,849
Cash equivalents:
Money market securities			37,099		-		-		37,099
Total cash equivalents			37,099		-		-		37,099
Total cash and cash equivalents			122,948		-		-		122,948
Short-term investments:
State and municipal bonds			33,155		25		-9		33,171
Total short-term investments			33,155		25		-9		33,171
Total cash, cash equivalents and short-term investments		$	156,103	$	25	$	-9	$	156,119
The following table summarizes the cost and estimated fair value of short-term fixed income securities classified as short-term investments based on stated effective maturities as of October 3, 2014:
		Amortized		Estimated
(In thousands)		Cost		Fair Value
Due within one year		$	18,873	$	18,897
Due between one and two years			7,104		7,112
Total		$	25,977	$	26,009
At October 3, 2014 and January 3, 2014, the Company did not have any assets or liabilities valued using significant unobservable inputs.
The following financial instruments are not measured at fair value on the Company's consolidated balance sheet at October 3, 2014 and January 3, 2014, but require disclosure of their fair values: accounts receivable, other assets and accounts payable. The estimated fair value of such instruments at October 3, 2014 and January 3, 2014 approximates their carrying value as reported on the consolidated balance sheet due to their generally short maturities. If measured at fair value in the financial statements, these instruments would be categorized as Level 2 on the fair value hierarchy.
There were no other-than-temporary impairments or credit losses related to available-for-sale securities during the three and nine months ended October 3, 2014 and September 27, 2013.

Net_Income_Per_Share

Net Income Per Share	9 Months Ended
	Oct. 03, 2014
Earnings Per Share [Abstract]	'
Net Income Per Share	'
	Note 3: Net Income Per Share
	Basic per share amounts are computed using the weighted-average number of common shares outstanding during the period. Diluted per share amounts are calculated using the weighted-average number of common shares outstanding during the period and, when dilutive, the weighted-average number of potential common shares from the issuance of common stock to satisfy outstanding restricted stock units and the exercise of outstanding options to purchase common stock using the treasury stock method.
	The following schedule reconciles the shares used to calculate basic and diluted net income per share:
		Three Months Ended				Nine Months Ended
	(In thousands)	October 3, 2014		September 27,		October 3,		September 27,
				2013		2014		2013
	Shares used in basic per share computation		13,469		13,598		13,509		13,638
	Effect of dilutive common stock options outstanding		59		83		69		78
	Effect of dilutive restricted stock units outstanding		296		312		311		331
	Shares used in diluted per share computation		13,824		13,993		13,889		14,047
	There were no options excluded from the diluted per share calculations for the three and nine months ended October 3, 2014 and September 27, 2013.

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
	Oct. 03, 2014
Share-Based Compensation [Abstract]	'
Stock-Based Compensation	'
	Note 4: Stock-Based Compensation
	Restricted Stock Units
	Restricted stock unit grants are designed to attract and retain employees, and to better align employee interests with those of the Company’s stockholders. For a select group of employees, up to 40% of their annual bonus is settled with fully vested restricted stock unit awards. Under these fully vested restricted stock unit awards, the holder of each award has the right to receive one share of the Company’s common stock for each fully vested restricted stock unit four years from the date of grant. Each individual who receives a fully vested restricted stock unit award is also granted a matching number of unvested restricted stock unit awards. Unvested restricted stock unit awards are also granted for select new hires and promotions. These unvested restricted stock unit awards generally cliff vest four years from the date of grant, at which time the holder of each award will have the right to receive one share of the Company’s common stock for each restricted stock unit award provided the holder of each award has met certain employment conditions. In the case of retirement at 59½ years or older, all unvested restricted stock unit awards will continue to vest, provided that the holder of each award does all consulting work through the Company and does not become an employee for a past or present client, beneficial party or competitor of the Company.
	The value of these restricted stock unit awards is determined based on the market price of the Company’s common stock on the date of grant. The value of fully vested restricted stock unit awards issued is recorded as a reduction to accrued bonuses. The portion of bonus expense that the Company expects to settle with fully vested restricted stock unit awards is recorded as stock-based compensation during the period the bonus is earned. The Company recorded stock-based compensation expense associated with accrued bonus awards of $1,657,000 and $1,557,000 during the three months ended October 3, 2014 and September 27, 2013, respectively. For the nine months ended October 3, 2014 and September 27, 2013, the Company recorded stock-based compensation expense associated with accrued bonus awards of $4,825,000 and $4,695,000, respectively. The value of the unvested restricted stock unit awards granted is recognized on a straight-line basis over the shorter of the four-year vesting period or the period between the grant date and the date the award recipient turns 59½. If the award recipient is 59½ years or older on the date of grant, the value of the entire award is expensed upon grant. The Company recorded stock-based compensation expense associated with the unvested restricted stock unit awards of $982,000 and $844,000 during the three months ended October 3, 2014 and September 27, 2013, respectively. The Company recorded stock-based compensation expense associated with the unvested restricted stock unit awards of $5,145,000 and $5,169,000 during the nine months ended October 3, 2014 and September 27, 2013, respectively.
	Stock Options
	Stock options are granted for terms of ten years and generally vest 25% per year over a four-year period from the grant date. For options granted on or after January 1, 2012, all unvested stock option awards will continue to vest in the case of retirement at 59½ or older, provided that the holder of each award does all consulting work through the Company and does not become an employee for a past or present client, beneficial party or competitor of the Company. The Company grants options at exercise prices equal to the fair value of the Company’s common stock on the date of grant. The Company recorded stock-based compensation expense of $71,000 and $100,000 during the three months ended October 3, 2014 and September 27, 2013, respectively, associated with stock option grants. The Company recorded stock-based compensation expense of $615,000 and $969,000 during the nine months ended October 3, 2014 and September 27, 2013, respectively, associated with stock option grants.
	The Company uses the Black-Scholes option-pricing model to determine the fair value of options granted. The determination of the fair value of stock-based awards on the date of grant using an option-pricing model is affected by the Company’s stock price as well as assumptions regarding a number of complex and subjective variables. These variables include expected stock price volatility over the term of the award, actual and projected employee stock option exercise behaviors, the risk-free interest rate and expected dividends.
	The Company used historical exercise and post-vesting forfeiture and expiration data to estimate the expected term of options granted. The historical volatility of the Company’s common stock over a period of time equal to the expected term of the options granted was used to estimate expected volatility. The risk-free interest rate used in the option-pricing model was based on United States Treasury zero-coupon issues with remaining terms similar to the expected term on the options. The Company is required to estimate forfeitures at the time of grant and revise those estimates in subsequent periods if actual forfeitures differ from those estimates. Historical data was used to estimate pre-vesting option forfeitures and stock-based compensation expense was recorded only for those awards that are expected to vest. All share-based payment awards are recognized on a straight-line basis over the requisite service periods of the awards.

Treasury_Stock

Treasury Stock	9 Months Ended
	Oct. 03, 2014
Equity [Abstract]	'
Treasury Stock	'
	Note 5: Treasury Stock
	On February 9, 2012, the Company’s Board of Directors authorized $35,000,000 for the repurchase of the Company’s common stock. On February 15, 2013, the Company’s Board of Directors authorized an additional $35,000,000 for the repurchase of the Company’s common stock. On May 29, 2014, the Company’s Board of Directors authorized an additional $35,000,000 for the repurchase of the Company’s common stock.
	The Company repurchased 383,639 shares of its common stock for $27,923,000 during the nine months ended October 3, 2014.  The Company repurchased 388,604 shares of its common stock for $21,211,000 during the nine months ended September 27, 2013.  As of October 3, 2014, the Company had remaining authorization under its stock repurchase plans of $38,077,000 to repurchase shares of its common stock.
	Net losses related to the re-issuance of treasury stock to settle restricted stock unit and stock option awards of $0 and $140,000 were recorded as a reduction to retained earnings during the three months ended October 3, 2014 and September 27, 2013, respectively. Net losses related to the re-issuance of treasury stock to settle restricted stock unit and stock option awards of $6,050,000 and $10,253,000 were recorded as a reduction to retained earnings during the nine months ended October 3, 2014 and September 27, 2013, respectively.

Deferred_Compensation_Plan

Deferred Compensation Plan	9 Months Ended
	Oct. 03, 2014
Deferred Compensation Arrangements [Abstract]	'
Deferred Compensation Plan	'
	Note 6: Deferred Compensation Plan
	The Company maintains a nonqualified deferred compensation plan for the benefit of a select group of highly compensated employees. Under this plan, participants may elect to defer up to 100% of their compensation. Company assets that are earmarked to pay benefits under the plan are held in a rabbi trust and are subject to the claims of the Company’s creditors. As of October 3, 2014 and January 3, 2014, the invested amounts under the plan totaled $42,098,000 and $37,979,000, respectively. These assets are classified as trading securities and are recorded at fair value with changes recorded as adjustments to other income and expense.
	As of October 3, 2014 and January 3, 2014, vested amounts due under the plan totaled $43,832,000 and $37,926,000, respectively. Changes in the liability are recorded as adjustments to compensation expense. During the three months ended October 3, 2014 and September 27, 2013, the Company recognized compensation expense of ($1,331,000) and $1,893,000, respectively, as a result of changes in the market value of the trust assets with the same amount being recorded as expense/income in other income (expense), net. During the nine months ended October 3, 2014 and September 27, 2013, the Company recognized compensation expense of $1,351,000 and $4,128,000, respectively, as a result of changes in the market value of the trust assets with the same amount being recorded as income in other income (expense), net.

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	9 Months Ended
	Oct. 03, 2014
Supplemental Cash Flow Information [Abstract]	'
Supplemental Cash Flow Information	'
	Note 7: Supplemental Cash Flow Information
	The following is supplemental disclosure of cash flow information:
		Nine Months Ended
	(In thousands)	October 3,		September 27, 2013
		2014
	Cash paid during period:
	Income taxes	$	17,458	$	17,027
	Non-cash investing and financing activities:
	Unrealized gain (loss) on available for sale investment
	securities, net of tax	$	9	$	-25
	Vested stock unit awards issued to settle accrued bonuses	$	6,008	$	5,807
	Accrual for capital expenditures	$	164	$	-

Accounts_Receivable_Net

Accounts Receivable, Net	9 Months Ended
	Oct. 03, 2014
Receivables [Abstract]	'
Accounts Receivable, Net	'
	Note 8: Accounts Receivable, Net
	At October 3, 2014 and January 3, 2014, accounts receivable, net, was comprised of the following:
		October 3,		January 3,
	(In thousands)	2014		2014
	Billed accounts receivable	$	59,240	$	52,674
	Unbilled accounts receivable		33,090		27,077
	Allowance for doubtful accounts		-3,241		-2,771
	Total accounts receivable, net	$	89,089	$	76,980

Segment_Reporting

Segment Reporting	9 Months Ended
	Oct. 03, 2014
Disclosure Segment Information [Abstract]	'
Segment Reporting	'
	Note 9: Segment Reporting
	The Company has two operating segments based on two primary areas of service. The Engineering and Other Scientific operating segment is a broad service group providing technical consulting in different practices primarily in the areas of engineering and technology development. The Environmental and Health operating segment provides services in the area of environmental, epidemiology and health risk analysis. This operating segment provides a wide range of consulting services relating to environmental hazards and risks and the impact on both human health and the environment.
	Segment information for the three and nine months ended October 3, 2014 and September 27, 2013 follows:
	Revenues
		Three Months Ended				Nine Months Ended
	(In thousands)	October 3,		September 27,		October 3,		September 27,
		2014		2013		2014		2013
	Engineering and Other Scientific	$	57,491	$	56,395	$	168,611	$	163,353
	Environmental and Health		21,066		18,836		62,482		60,043
	Total revenues	$	78,557	$	75,231	$	231,093	$	223,396
	Operating Income
		Three Months Ended				Nine Months Ended
	(In thousands)	October 3,		September 27,		October 3,		September 27,
		2014		2013		2014		2013
	Engineering and Other Scientific	$	18,939	$	18,115	$	55,457	$	51,747
	Environmental and Health		7,007		5,624		20,171		19,104
	Total segment operating income		25,946		23,739		75,628		70,851
	Corporate operating expense		-6,708		-8,579		-26,212		-27,247
	Total operating income	$	19,238	$	15,160	$	49,416	$	43,604
	Capital Expenditures
		Three Months Ended				Nine Months Ended
	(In thousands)	October 3,		September 27,		October 3,		September 27,
		2014		2013		2014		2013
	Engineering and Other Scientific	$	1,509	$	664	$	2,833	$	3,924
	Environmental and Health		36		41		151		110
	Total segment capital expenditures		1,545		705		2,984		4,034
	Corporate capital expenditures		385		187		922		559
	Total capital expenditures	$	1,930	$	892	$	3,906	$	4,593
	Depreciation and Amortization
		Three Months Ended				Nine Months Ended
	(In thousands)	October 3,		September 27,		October 3,		September 27,
		2014		2013		2014		2013
	Engineering and Other Scientific	$	923	$	813	$	2,664	$	2,269
	Environmental and Health		49		76		145		221
	Total segment depreciation and amortization		972		889		2,809		2,490
	Corporate depreciation and amortization		374		394		1,170		1,177
	Total depreciation and amortization	$	1,346	$	1,283	$	3,979	$	3,667
	No single customer comprised more than 10% of the Company’s revenues during the three or nine months ended October 3, 2014 and September 27, 2013. No single customer comprised more than 10% of the Company’s accounts receivable at October 3, 2014 and January 3, 2014.

Goodwill

Goodwill	9 Months Ended
	Oct. 03, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill	'
	Note 10: Goodwill
	Below is a breakdown of goodwill reported by segment as of October 3, 2014:
		Environmental		Engineering and
	(In thousands)	and Health		Other Scientific		Total
	Goodwill	$	8,099	$	508	$	8,607
	There were no acquisitions, dispositions, impairments or other changes in the carrying amount of goodwill, nor any changes in the composition of the Company’s reporting units, during the three and nine months ended October 3, 2014.

Contingencies

Contingencies	9 Months Ended
	Oct. 03, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Contingencies	'
	Note 11: Contingencies
	The Company is a party to various legal actions from time to time and may be contingently liable in connection with claims and contracts arising in the normal course of business, the outcome of which the Company believes, after consultation with legal counsel, will not have a material adverse effect on its financial condition, results of operations or liquidity. However, due to the risks and uncertainties inherent in legal proceedings, actual results could differ from current expected results. All legal costs associated with litigation are expensed as incurred.

Basis_of_Presentation_Tables

Basis of Presentation (Tables)	9 Months Ended
	Oct. 03, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Common Stock Dividends Declared Per Share	'
	The Company declared and paid cash dividends per common share during the periods presented as follows:
		Fiscal Year 2014
		Dividends		Amount
		Per Share		(in thousands)
	First Quarter	$	0.25	$	3,262
	Second Quarter	$	0.25		3,270
	Third Quarter	$	0.25		3,262
				$	9,794
		Fiscal Year 2013
		Dividends		Amount
		Per Share		(in thousands)
	First Quarter	$	0.15	$	1,969
	Second Quarter	$	0.15		1,998
	Third Quarter	$	0.15		1,945
	Fourth Quarter	$	0.15		1,965
				$	7,877

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Oct. 03, 2014
Fair Value Disclosures [Abstract]	'
Assets and Liabilities Measured at Fair Value on Recurring Basis	'
	The fair value of these certain financial assets and liabilities was determined using the following inputs at October 3, 2014:
			Fair Value Measurements at Reporting Date Using
	(In thousands)		Total		Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable
					Identical Assets		(Level 2)		Inputs
					(Level 1)				(Level 3)
	Assets
	Money market
	securities (1)		$	44,246	$	44,246	$	-	$	-
	Fixed income available
	for sale securities (2)			26,009		-		26,009		-
	Fixed income trading
	securities held in deferred
	compensation plan (3)			9,759		9,759		-		-
	Equity trading securities
	held in deferred
	compensation plan (3)			32,339		32,339		-		-
	Total		$	112,353	$	86,344	$	26,009	$	-
	Liabilities
	Deferred compensation
	plan (4)			43,832		43,832		-		-
	Total		$	43,832	$	43,832	$	-	$	-
		-1	Included in cash and cash equivalents on the Company’s unaudited condensed consolidated balance sheet.
		-2	Included in short-term investments on the Company’s unaudited condensed consolidated balance sheet.
		-3	Included in prepaid expenses and other assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet.
		-4	Included in accrued payroll and employee benefits and deferred compensation on the Company’s unaudited condensed consolidated balance sheet.
	The fair value of these certain financial assets and liabilities was determined using the following inputs at January 3, 2014:
			Fair Value Measurements at Reporting Date Using
	(In thousands)		Total		Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable
					Identical Assets		(Level 2)		Inputs
					(Level 1)				(Level 3)
	Assets
	Money market
	securities (1)		$	37,099	$	37,099	$	-	$	-
	Fixed income available
	for sale securities (2)			33,171		-		33,171		-
	Fixed income trading
	securities held in deferred
	compensation plan (3)			9,535		9,535		-		-
	Equity trading securities
	held in deferred
	compensation plan (3)			28,444		28,444		-		-
	Total		$	108,249	$	75,078	$	33,171	$	-
	Liabilities
	Deferred compensation
	plan (4)			37,926		37,926		-		-
	Total		$	37,926	$	37,926	$	-	$	-
		-1	Included in cash and cash equivalents on the Company’s consolidated balance sheet.
		-2	Included in short-term investments on the Company’s consolidated balance sheet.
		-3	Included in prepaid expenses and other assets and deferred compensation plan assets on the Company’s consolidated balance sheet.
		-4	Included in accrued payroll and employee benefits and deferred compensation on the Company’s consolidated balance sheet.
Cash, cash equivalents and short-term investments	'
	Cash, cash equivalents and short-term investments consisted of the following as of October 3, 2014:
			Amortized		Unrealized		Unrealized		Estimated
	(In thousands)		Cost		Gains		Losses		Fair Value
	Classified as current assets:
	Cash		$	71,368	$	-	$	-	$	71,368
	Cash equivalents:
	Money market securities			44,246		-		-		44,246
	Total cash equivalents			44,246		-		-		44,246
	Total cash and cash equivalents			115,614		-		-		115,614
	Short-term investments:
	State and municipal bonds			25,977		36		-4		26,009
	Total short-term investments			25,977		36		-4		26,009
	Total cash, cash equivalents and short-term investments		$	141,591	$	36	$	-4	$	141,623
	Cash, cash equivalents and short-term investments consisted of the following as of January 3, 2014:
			Amortized		Unrealized		Unrealized		Estimated
	(In thousands)		Cost		Gains		Losses		Fair Value
	Classified as current assets:
	Cash		$	85,849	$	-	$	-	$	85,849
	Cash equivalents:
	Money market securities			37,099		-		-		37,099
	Total cash equivalents			37,099		-		-		37,099
	Total cash and cash equivalents			122,948		-		-		122,948
	Short-term investments:
	State and municipal bonds			33,155		25		-9		33,171
	Total short-term investments			33,155		25		-9		33,171
	Total cash, cash equivalents and short-term investments		$	156,103	$	25	$	-9	$	156,119
Summary of Cost and Estimated Fair Value of Short Term Fixed Income Securities	'
	The following table summarizes the cost and estimated fair value of short-term fixed income securities classified as short-term investments based on stated effective maturities as of October 3, 2014:
			Amortized		Estimated
	(In thousands)		Cost		Fair Value
	Due within one year		$	18,873	$	18,897
	Due between one and two years			7,104		7,112
	Total		$	25,977	$	26,009

Net_Income_Per_Share_Tables

Net Income Per Share (Tables)	9 Months Ended
	Oct. 03, 2014
Earnings Per Share [Abstract]	'
Reconciles Shares to Calculate Basic and Diluted Net Income Per Share	'
	The following schedule reconciles the shares used to calculate basic and diluted net income per share:
		Three Months Ended				Nine Months Ended
	(In thousands)	October 3, 2014		September 27,		October 3,		September 27,
				2013		2014		2013
	Shares used in basic per share computation		13,469		13,598		13,509		13,638
	Effect of dilutive common stock options outstanding		59		83		69		78
	Effect of dilutive restricted stock units outstanding		296		312		311		331
	Shares used in diluted per share computation		13,824		13,993		13,889		14,047

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Oct. 03, 2014
Supplemental Cash Flow Information [Abstract]	'
Supplemental Disclosure of Cash Flow Information	'
	The following is supplemental disclosure of cash flow information:
		Nine Months Ended
	(In thousands)	October 3,		September 27, 2013
		2014
	Cash paid during period:
	Income taxes	$	17,458	$	17,027
	Non-cash investing and financing activities:
	Unrealized gain (loss) on available for sale investment
	securities, net of tax	$	9	$	-25
	Vested stock unit awards issued to settle accrued bonuses	$	6,008	$	5,807
	Accrual for capital expenditures	$	164	$	-

Accounts_Receivable_Net_Tables

Accounts Receivable, Net (Tables)	9 Months Ended
	Oct. 03, 2014
Receivables [Abstract]	'
Accounts Receivable, Net	'
	At October 3, 2014 and January 3, 2014, accounts receivable, net, was comprised of the following:
		October 3,		January 3,
	(In thousands)	2014		2014
	Billed accounts receivable	$	59,240	$	52,674
	Unbilled accounts receivable		33,090		27,077
	Allowance for doubtful accounts		-3,241		-2,771
	Total accounts receivable, net	$	89,089	$	76,980

Segment_Reporting_Tables

Segment Reporting (Tables)	9 Months Ended
	Oct. 03, 2014
Disclosure Segment Information [Abstract]	'
Segment Reporting Information, by Segment	'
	Segment information for the three and nine months ended October 3, 2014 and September 27, 2013 follows:
	Revenues
		Three Months Ended				Nine Months Ended
	(In thousands)	October 3,		September 27,		October 3,		September 27,
		2014		2013		2014		2013
	Engineering and Other Scientific	$	57,491	$	56,395	$	168,611	$	163,353
	Environmental and Health		21,066		18,836		62,482		60,043
	Total revenues	$	78,557	$	75,231	$	231,093	$	223,396
	Operating Income
		Three Months Ended				Nine Months Ended
	(In thousands)	October 3,		September 27,		October 3,		September 27,
		2014		2013		2014		2013
	Engineering and Other Scientific	$	18,939	$	18,115	$	55,457	$	51,747
	Environmental and Health		7,007		5,624		20,171		19,104
	Total segment operating income		25,946		23,739		75,628		70,851
	Corporate operating expense		-6,708		-8,579		-26,212		-27,247
	Total operating income	$	19,238	$	15,160	$	49,416	$	43,604
	Capital Expenditures
		Three Months Ended				Nine Months Ended
	(In thousands)	October 3,		September 27,		October 3,		September 27,
		2014		2013		2014		2013
	Engineering and Other Scientific	$	1,509	$	664	$	2,833	$	3,924
	Environmental and Health		36		41		151		110
	Total segment capital expenditures		1,545		705		2,984		4,034
	Corporate capital expenditures		385		187		922		559
	Total capital expenditures	$	1,930	$	892	$	3,906	$	4,593
	Depreciation and Amortization
		Three Months Ended				Nine Months Ended
	(In thousands)	October 3,		September 27,		October 3,		September 27,
		2014		2013		2014		2013
	Engineering and Other Scientific	$	923	$	813	$	2,664	$	2,269
	Environmental and Health		49		76		145		221
	Total segment depreciation and amortization		972		889		2,809		2,490
	Corporate depreciation and amortization		374		394		1,170		1,177
	Total depreciation and amortization	$	1,346	$	1,283	$	3,979	$	3,667

Goodwill_Tables

Goodwill (Tables)	9 Months Ended
	Oct. 03, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Breakdown of Goodwill Reported by Segment	'
	Below is a breakdown of goodwill reported by segment as of October 3, 2014:
		Environmental		Engineering and
	(In thousands)	and Health		Other Scientific		Total
	Goodwill	$	8,099	$	508	$	8,607

Common_Stock_Dividends_Declare

Common Stock Dividends Declared And Paid Per Share (Detail) (USD $)	3 Months Ended							9 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Oct. 03, 2014	Jul. 04, 2014	Apr. 04, 2014	Jan. 03, 2014	Sep. 27, 2013	Jun. 28, 2013	Mar. 29, 2013	Oct. 03, 2014	Jan. 03, 2014
Common Stock Dividends [Line Items]	'	'	'	'	'	'	'	'	'
Dividends Per Share	$0.25	$0.25	$0.25	$0.15	$0.15	$0.15	$0.15	'	'
Dividends, Total	$3,262	$3,270	$3,262	$1,965	$1,945	$1,998	$1,969	$9,794	$7,877

Basis_of_Presentation_Addition

Basis of Presentation - Additional Information (Detail) (USD $)	Oct. 22, 2014	23-May-06
In Millions, except Per Share data, unless otherwise specified
Limits On Use Of Authorized Capital Stock [Line Items]	'	'
Limits on use of authorized common stock shares	'	40
Limits on use of authorized preferred stock shares	'	2
Common stock, dividends per share declared, subsequent event	$0.25	'

Assets_and_Liabilities_Measure

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Oct. 03, 2014		Jan. 03, 2014
In Thousands, unless otherwise specified
Assets	'		'
Money market securities	$44,246	[1]	$37,099	[2]
Total	112,353		108,249
Liabilities	'		'
Deferred compensation plan	43,832	[3]	37,926	[4]
Total	43,832		37,926
Fixed income securities	'		'
Assets	'		'
Fixed income available for sale securities	26,009	[5]	33,171	[6]
Fixed income trading securities held in deferred compensation plan	9,759	[7]	9,535	[8]
Equity securities	'		'
Assets	'		'
Equity trading securities held in deferred compensation plan	32,339	[7]	28,444	[8]
Fair Value, Inputs, Level 1	'		'
Assets	'		'
Money market securities	44,246	[1]	37,099	[2]
Total	86,344		75,078
Liabilities	'		'
Deferred compensation plan	43,832	[3]	37,926	[4]
Total	43,832		37,926
Fair Value, Inputs, Level 1 | Fixed income securities	'		'
Assets	'		'
Fixed income available for sale securities	0	[5]	0	[6]
Fixed income trading securities held in deferred compensation plan	9,759	[7]	9,535	[8]
Fair Value, Inputs, Level 1 | Equity securities	'		'
Assets	'		'
Equity trading securities held in deferred compensation plan	32,339	[7]	28,444	[8]
Fair Value, Inputs, Level 2	'		'
Assets	'		'
Money market securities	0	[1]	0	[2]
Total	26,009		33,171
Liabilities	'		'
Deferred compensation plan	0	[3]	0	[4]
Total	0		0
Fair Value, Inputs, Level 2 | Fixed income securities	'		'
Assets	'		'
Fixed income available for sale securities	26,009	[5]	33,171	[6]
Fixed income trading securities held in deferred compensation plan	0	[7]	0	[8]
Fair Value, Inputs, Level 2 | Equity securities	'		'
Assets	'		'
Equity trading securities held in deferred compensation plan	0	[7]	0	[8]
Fair Value, Inputs, Level 3	'		'
Assets	'		'
Money market securities	0	[1]	0	[2]
Total	0		0
Liabilities	'		'
Deferred compensation plan	0	[3]	0	[4]
Total	0		0
Fair Value, Inputs, Level 3 | Fixed income securities	'		'
Assets	'		'
Fixed income available for sale securities	0	[5]	0	[6]
Fixed income trading securities held in deferred compensation plan	0	[7]	0	[8]
Fair Value, Inputs, Level 3 | Equity securities	'		'
Assets	'		'
Equity trading securities held in deferred compensation plan	$0	[7]	$0	[8]
[1]	Included in cash and cash equivalents on the Companybs unaudited condensed consolidated balance sheet.
[2]	Included in cash and cash equivalents on the Companybs consolidated balance sheet.
[3]	Included in accrued payroll and employee benefits and deferred compensation on the Companybs unaudited condensed consolidated balance sheet.
[4]	Included in accrued payroll and employee benefits and deferred compensation on the Companybs consolidated balance sheet.
[5]	Included in short-term investments on the Companybs unaudited condensed consolidated balance sheet.
[6]	Included in short-term investments on the Companybs consolidated balance sheet.
[7]	Included in prepaid expenses and other assets and deferred compensation plan assets on the Companybs unaudited condensed consolidated balance sheet.
[8]	Included in prepaid expenses and other assets and deferred compensation plan assets on the Companybs consolidated balance sheet.

Cash_Cash_Equivalents_And_Shor

Cash, Cash Equivalents And Short Term Investments (Detail) (USD $)	Oct. 03, 2014	Jan. 03, 2014
In Thousands, unless otherwise specified
Fair Value Measurements [Line Items]	'	'
Amortized Cost	$141,591	$156,103
Unrealized Gains	36	25
Unrealized Losses	-4	-9
Estimated Fair Value	141,623	156,119
Cash	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	71,368	85,849
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	71,368	85,849
Money market securities	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	44,246	37,099
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	44,246	37,099
Total cash equivalents	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	44,246	37,099
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	44,246	37,099
Total cash and cash equivalents	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	115,614	122,948
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	115,614	122,948
State and municipal bonds	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	25,977	33,155
Unrealized Gains	36	25
Unrealized Losses	-4	-9
Estimated Fair Value	26,009	33,171
Total short-term investments	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	25,977	33,155
Unrealized Gains	36	25
Unrealized Losses	-4	-9
Estimated Fair Value	$26,009	$33,171

Summarizes_Cost_And_Estimated_

Summarizes Cost And Estimated Fair Value Of Short Term Fixed Income Securities (Detail) (USD $)	Oct. 03, 2014	Jan. 03, 2014
In Thousands, unless otherwise specified
Fair Value Measurements [Line Items]	'	'
Due within one year, Amortized Cost	$18,873	'
Due between one and two years, Amortized Cost	7,104	'
Total Amortized Cost	25,977	'
Due within one year, Estimated Fair Value	18,897	'
Due between one and two years, Estimated Fair Value	7,112	'
Total Estimated Fair Value	$26,009	$33,171

Reconciliation_of_Shares_Used_

Reconciliation of Shares Used to Calculate Basic and Diluted Net Income Per Share (Detail)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Oct. 03, 2014	Sep. 27, 2013	Oct. 03, 2014	Sep. 27, 2013
Schedule Of Earnings Per Share Basic and Diluted [Line Items]	'	'	'	'
Shares used in basic per share computation	13,469	13,598	13,509	13,638
Shares used in diluted per share computation	13,824	13,993	13,889	14,047
Employee Stock Option	'	'	'	'
Schedule Of Earnings Per Share Basic and Diluted [Line Items]	'	'	'	'
Effect of dilutive stock outstanding	59	83	69	78
Restricted Stock Units (RSUs)	'	'	'	'
Schedule Of Earnings Per Share Basic and Diluted [Line Items]	'	'	'	'
Effect of dilutive stock outstanding	296	312	311	331

Net_Income_Per_Share_Additiona

Net Income Per Share - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Oct. 03, 2014	Sep. 27, 2013	Oct. 03, 2014	Sep. 27, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Options excluded from the diluted per share	0	0	0	0

StockBased_Compensation_Additi

Stock-Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Oct. 03, 2014	Sep. 27, 2013	Oct. 03, 2014	Sep. 27, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Share Based Compensation Arrangement By Share Based Payment Award Options Expiration Term	'	'	'10 years	'
Maximum	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Percentage of annual bonus settled with fully vested restricted stock unit awards	'	'	40.00%	'
Unvested Restricted Stock	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock based compensation, vesting period	'	'	'4 years	'
Unvested Restricted Stock | Minimum	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Recipient age to expense award on grant date	'	'	'59 years 6 months	'
Employee Stock Option	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock based compensation expense	$71,000	$100,000	$615,000	$969,000
Vesting percentage of stock options granted per year	'	'	25.00%	'
Stock based compensation, vesting period	'	'	'4 years	'
Vested Restricted Stock Awards	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock based compensation expense	1,657,000	1,557,000	4,825,000	4,695,000
Stock based compensation, holding period	'	'	'4 years	'
Unvested Restricted Stock Awards	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock based compensation expense	$982,000	$844,000	$5,145,000	$5,169,000
Unvested Stock Options | Minimum	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Recipient age to expense award on grant date	'	'	'59 years 6 months	'

Treasury_Stock_Additional_Info

Treasury Stock - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Oct. 03, 2014	Sep. 27, 2013	Oct. 03, 2014	Sep. 27, 2013	29-May-14	Feb. 15, 2013	Feb. 09, 2012
Equity, Class of Treasury Stock [Line Items]	'	'	'	'	'	'	'
Stock Repurchase Program, Authorized Amount	'	'	'	'	$35,000,000	$35,000,000	$35,000,000
Repurchase of treasury shares (in shares)	'	'	383,639	388,604	'	'	'
Repurchase of treasury shares	'	'	27,923,000	21,211,000	'	'	'
Remaining authorized amount for repurchase of common stock	38,077,000	'	38,077,000	'	'	'	'
Treasury stock reissued at lower than repurchase price	$0	$140,000	$6,050,000	$10,253,000	'	'	'

Deferred_Compensation_Plan_Add

Deferred Compensation Plan - Additional Information (Detail) (Deferred Compensation, Excluding Share-based Payments and Retirement Benefits, USD $)	3 Months Ended		9 Months Ended
	Oct. 03, 2014	Sep. 27, 2013	Oct. 03, 2014	Sep. 27, 2013	Jan. 03, 2014
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]	'	'	'	'	'
Trading securities	$42,098,000	'	$42,098,000	'	$37,979,000
Deferred compensation plan vested amounts due	43,832,000	'	43,832,000	'	37,926,000
Change in market value of trust assets	($1,331,000)	$1,893,000	$1,351,000	$4,128,000	'
Maximum	'	'	'	'	'
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]	'	'	'	'	'
Percentage of compensation deferred	'	'	100.00%	'	'

Supplemental_Disclosure_of_Cas

Supplemental Disclosure of Cash Flow Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Oct. 03, 2014	Sep. 27, 2013	Oct. 03, 2014	Sep. 27, 2013
Cash paid during period:	'	'	'	'
Income taxes	'	'	$17,458	$17,027
Non-cash investing and financing activities:	'	'	'	'
Unrealized gain (loss) on available for sale investment securities, net of tax	-13	-3	9	-25
Vested stock unit awards issued to settle accrued bonuses	'	'	6,008	5,807
Accrual for capital expenditures	'	'	$164	$0

Accounts_Receivable_Net_Detail

Accounts Receivable, Net (Detail) (USD $)	Oct. 03, 2014	Jan. 03, 2014
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Allowance for doubtful accounts	($3,241)	($2,771)
Total accounts receivable, net	89,089	76,980
Billed accounts receivable	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts receivable	59,240	52,674
Unbilled accounts receivable	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts receivable	$33,090	$27,077

Segment_Information_Detail

Segment Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Oct. 03, 2014	Sep. 27, 2013	Oct. 03, 2014	Sep. 27, 2013
Segment Reporting Information [Line Items]	'	'	'	'
Revenues	$78,557	$75,231	$231,093	$223,396
Operating income	19,238	15,160	49,416	43,604
Capital expenditures	1,930	892	3,906	4,593
Depreciation and amortization	1,346	1,283	3,979	3,667
Engineering and Other Scientific	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenues	57,491	56,395	168,611	163,353
Operating income	18,939	18,115	55,457	51,747
Capital expenditures	1,509	664	2,833	3,924
Depreciation and amortization	923	813	2,664	2,269
Environmental and Health	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenues	21,066	18,836	62,482	60,043
Operating income	7,007	5,624	20,171	19,104
Capital expenditures	36	41	151	110
Depreciation and amortization	49	76	145	221
Operating segments	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Operating income	25,946	23,739	75,628	70,851
Capital expenditures	1,545	705	2,984	4,034
Depreciation and amortization	972	889	2,809	2,490
Corporate	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Operating income	-6,708	-8,579	-26,212	-27,247
Capital expenditures	385	187	922	559
Depreciation and amortization	$374	$394	$1,170	$1,177

Segment_Reporting_Additional_I

Segment Reporting - Additional Information (Detail)	9 Months Ended
	Oct. 03, 2014	Jan. 03, 2014	Sep. 27, 2013
Segment Reporting Information [Line Items]	'	'	'
Number of operating segments	2	'	'
Percentage of account receivable	10.00%	10.00%	'
Percentage of Company's revenue	10.00%	'	10.00%

Breakdown_of_Goodwill_Reported

Breakdown of Goodwill Reported by Segment (Detail) (USD $)	Oct. 03, 2014	Jan. 03, 2014
In Thousands, unless otherwise specified
Goodwill [Line Items]	'	'
Goodwill	$8,607	$8,607
Environmental and Health	'	'
Goodwill [Line Items]	'	'
Goodwill	8,099	'
Engineering and Other Scientific	'	'
Goodwill [Line Items]	'	'
Goodwill	$508	'

Goodwill_Additional_Informatio

Goodwill - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
	Oct. 03, 2014	Oct. 03, 2014
Goodwill [Line Items]	'	'
Goodwill, Acquisitions	$0	$0
Goodwill, Dispositions	0	0
Goodwill, Impairments or other changes	0	0
Goodwill, Changes in the composition	$0	$0