Exponent (EXPO) 10-Q 1 Nov 13 2013 Q3 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	9 Months Ended
	Sep. 27, 2013	Oct. 25, 2013
Document Information [Line Items]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	27-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'EXPO	'
Entity Common Stock, Shares Outstanding	'	13,103,213
Entity Registrant Name	'EXPONENT INC	'
Entity Central Index Key	'0000851520	'
Current Fiscal Year End Date	'--01-03	'
Entity Filer Category	'Accelerated Filer	'

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 27, 2013	Dec. 28, 2012
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$121,747	$113,268
Short-term investments	13,296	20,881
Accounts receivable, net of allowance for doubtful accounts of $2,772 and $2,666 at September 27, 2013 and December 28, 2012, respectively	82,177	85,361
Prepaid expenses and other assets	9,512	8,277
Deferred income taxes	8,295	7,657
Total current assets	235,027	235,444
Property, equipment and leasehold improvements, net	28,372	27,446
Goodwill	8,607	8,607
Deferred income taxes	20,489	18,359
Deferred compensation plan assets	31,386	24,801
Other assets	596	760
Total assets	324,477	315,417
Current liabilities:	'	'
Accounts payable and accrued liabilities	5,139	10,386
Accrued payroll and employee benefits	47,645	54,720
Deferred revenues	6,155	6,665
Total current liabilities	58,939	71,771
Other liabilities	1,164	988
Deferred compensation	31,319	24,697
Deferred rent	2,416	1,532
Total liabilities	93,838	98,988
Stockholders' equity:	'	'
Common stock, $0.001 par value; 100,000 shares authorized; 16,427 shares issued at September 27, 2013 and December 28, 2012	16	16
Additional paid-in capital	140,013	123,693
Accumulated other comprehensive loss	'	'
Investment securities, available for sale	-1	24
Foreign currency translation adjustments	-155	-274
Accumulated Other Comprehensive Income (Loss), Net of Tax, Total	-156	-250
Retained earnings	219,493	206,057
Treasury stock, at cost; 3,327 and 3,221 shares held at September 27, 2013 and December 28, 2012, respectively	-128,727	-113,087
Total stockholders' equity	230,639	216,429
Total liabilities and stockholders' equity	$324,477	$315,417

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 27, 2013	Dec. 28, 2012
In Thousands, except Per Share data, unless otherwise specified
Accounts receivable, allowance for contract losses and doubtful accounts	$2,772	$2,666
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	3,327	3,221

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
Revenues:	'	'	'	'
Revenues before reimbursements	$70,096	$66,725	$211,007	$201,513
Reimbursements	5,135	6,573	12,389	18,194
Revenues	75,231	73,298	223,396	219,707
Operating expenses:	'	'	'	'
Compensation and related expenses	44,801	42,589	137,795	130,621
Other operating expenses	6,440	5,908	18,794	17,422
Reimbursable expenses	5,135	6,573	12,389	18,194
General and administrative expenses	3,695	3,500	10,814	9,565
Total operating expenses	60,071	58,570	179,792	175,802
Operating income	15,160	14,728	43,604	43,905
Other income, net:	'	'	'	'
Interest income, net	14	80	95	245
Miscellaneous income, net	2,341	1,522	5,592	3,161
Total other income, net	2,355	1,602	5,687	3,406
Income before income taxes	17,515	16,330	49,291	47,311
Income taxes	6,421	6,105	19,373	18,558
Net income	$11,094	$10,225	$29,918	$28,753
Net income per share:	'	'	'	'
Basic	$0.82	$0.75	$2.19	$2.08
Diluted	$0.79	$0.72	$2.13	$2.01
Shares used in per share computations:	'	'	'	'
Basic	13,598	13,694	13,638	13,796
Diluted	13,993	14,196	14,047	14,317

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
Net income	$11,094	$10,225	$29,918	$28,753
Other comprehensive income (loss):	'	'	'	'
Foreign currency translation adjustments, net of tax	556	306	119	227
Unrealized loss on investments, net of tax	-3	-17	-25	-5
Comprehensive income	$11,647	$10,514	$30,012	$28,975

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012
Cash flows from operating activities:	'	'
Net income	$29,918	$28,753
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization of property, equipment and leasehold improvements	3,667	3,459
Amortization of premiums and accretion of discounts on short-term investments	165	428
Deferred rent	884	-296
Provision for doubtful accounts	822	1,304
Stock-based compensation	10,832	9,932
Deferred income tax provision	-2,770	-2,780
Tax benefit for stock plans	-4,064	-2,762
Changes in operating assets and liabilities:	'	'
Accounts receivable	2,362	-16,594
Prepaid expenses and other assets	-3,498	-4,849
Accounts payable and accrued liabilities	-521	6,574
Accrued payroll and employee benefits	-3,469	-925
Deferred revenues	-510	-610
Net cash provided by operating activities	33,818	21,634
Cash flows from investing activities:	'	'
Capital expenditures	-4,593	-3,425
Purchase of short-term investments	-11,813	-515
Maturity of short-term investments	19,190	2,735
Sale of short-term investments	0	518
Net cash provided by (used in) investing activities	2,784	-687
Cash flows from financing activities:	'	'
Tax benefit for stock plans	4,064	2,762
Payroll taxes for restricted stock units	-6,112	-3,531
Repurchase of common stock	-21,719	-19,437
Exercise of share-based payment awards	1,497	2,071
Dividends paid	-5,962	0
Net cash used in financing activities	-28,232	-18,135
Effect of foreign currency exchange rates on cash and cash equivalents	109	402
Net increase in cash and cash equivalents	8,479	3,214
Cash and cash equivalents at beginning of period	113,268	84,439
Cash and cash equivalents at end of period	$121,747	$87,653

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 27, 2013
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 September 27, 2013 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 December 28, 2012 which was filed with the U.S. Securities and Exchange Commission on February 28, 2013.
	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.  On April 16, 2013, the Company declared a cash dividend of $0.15 per share of the Company’s common stock, paid on June 28, 2013, to stockholders of record as of June 7, 2013.   On July 22, 2013, the Company declared a cash dividend of $0.15 per share of the Company’s common stock, paid on September 27, 2013, to stockholders of record as of September 6, 2013.  On October 15, 2013, the Company declared a cash dividend of $0.15 per share of the Company’s common stock, payable on December 20, 2013, to stockholders of record as of November 29, 2013.  The Company expects to continue paying quarterly dividends in the future, subject to declaration by the Company’s Board of Directors.
	Recently Adopted Accounting Pronouncements.  In February 2013, the Financial Accounting Standards Board (“FASB”) issued a new accounting standard for reporting of amounts reclassified out of accumulated other comprehensive income.  The new standard does not change the current requirements for reporting net income or comprehensive income in financial statements.  However, the new standard requires an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component.  In addition, an entity is required to present, either on the face of the statement where net income is presented or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income but only if the amount reclassified is required under U.S. GAAP to be reclassified to net income in its entirety in the same reporting period.  Effective December 29, 2012, the Company adopted this standard.  There were no amounts reclassified from accumulated other comprehensive income to net income during the three and nine months ended September 27, 2013.
	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.  Actual results could differ from those estimates.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 27, 2013
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 September 27, 2013 and September 28, 2012. 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 September 27, 2013:
			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)		$	56,938	$	56,938	$	-	$	-
	Fixed income available
	for sale securities (2)			13,296		-		13,296		-
	Fixed income trading
	securities held in deferred
	compensation plan (3)			9,921		9,921		-		-
	Equity trading securities
	held in deferred
	compensation plan (3)			25,578		25,578		-		-
	Total		$	105,733	$	92,437	$	13,296	$	-
	Liabilities
	Deferred compensation
	plan (4)			35,431		35,431		-		-
	Total		$	35,431	$	35,431	$	-	$	-
	-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 other current assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet.
	-4	Included in accrued liabilities 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 December 28, 2012:
			Fair Value Measurements at Reporting Date Using
	(In thousands)		Total		Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable Inputs
					Identical Assets		(Level 2)		(Level 3)
					(Level 1)
	Assets
	Money market
	securities (1)		$	49,134	$	49,134	$	-	$	-
	Fixed income available
	for sale securities (2)			20,881		-		20,881		-
	Fixed income trading
	securities held in deferred
	compensation plan (3)			9,911		9,911		-		-
	Equity trading securities
	held in deferred
	compensation plan (3)			17,178		17,178		-		-
	Total		$	97,104	$	76,223	$	20,881	$	-
	Liabilities
	Deferred compensation
	plan (4)			26,984		26,984		-		-
	Total		$	26,984	$	26,984	$	-	$	-
	-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 other current assets and deferred compensation plan assets on the Company’s consolidated balance sheet.
	-4	Included in accrued liabilities and deferred compensation on the Company’s consolidated balance sheet.
	Fixed income available-for-sale securities as of September 27, 2013 and December 28, 2012 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 September 27, 2013:
				Amortized	Unrealized			Unrealized		Estimated
	(In thousands)		Cost		Gains		Losses		Fair Value
	Classified as current assets:
	Cash		$	64,809	$	-	$	-	$	64,809
	Cash equivalents:
	Money market securities			56,938		-		-		56,938
	Total cash equivalents			56,938		-		-		56,938
	Total cash and cash equivalents			121,747		-		-		121,747
Short-term investments:
State and municipal bonds			13,299		3		-6		13,296
Total short-term investments			13,299		3		-6		13,296
Total cash, cash equivalents
and short-term investments		$	135,046	$	3	$	-6	$	135,043
There were no securities in a continuous unrealized loss position for more than 12 months as of September 27, 2013.
Cash, cash equivalents and short-term investments consisted of the following as of December 28, 2012:
			Amortized		Unrealized		Unrealized		Estimated
(In thousands)		Cost		Gains		Losses		Fair Value
Classified as current assets:
Cash		$	64,134	$	-	$	-	$	64,134
Cash equivalents:
Money market securities			49,134		-		-		49,134
Total cash equivalents			49,134		-		-		49,134
Total cash and cash equivalents			113,268		-		-		113,268
Short-term investments:
State and municipal bonds			20,841		41		-1		20,881
Total short-term investments			20,841		41		-1		20,881
Total cash, cash equivalents
and short-term investments		$	134,109	$	41	$	-1	$	134,149
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 September 27, 2013:
		Amortized		Estimated
(In thousands)		Cost		Fair Value
Due within one year		$	6,069	$	6,066
Due between one and two years			6,357		6,357
Due between two and three years			873		873
Total		$	13,299	$	13,296
At September 27, 2013 and December 28, 2012, 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 September 27, 2013 and December 28, 2012, but require disclosure of their fair values: accounts receivable, other assets and accounts payable. The estimated fair value of such instruments at September 27, 2013 and December 28, 2012 approximates their carrying value as reported on the consolidated balance sheet. The fair values of such financial instruments are determined using the income approach based on the present value of estimated future cash flows. There have been no changes in the Company’s valuation technique during fiscal 2013. The fair value of all of these instruments would be categorized as Level 2 of the fair value hierarchy.
There were no other-than-temporary impairments or credit losses related to available-for-sale securities during the nine months ended September 27, 2013 and September 28, 2012.

Net_Income_Per_Share

Net Income Per Share	9 Months Ended
	Sep. 27, 2013
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)	September 27,	September 28,	September 27,	September 28,
		2013	2012	2013	2012
	Shares used in basic per share computation	13,598	13,694	13,638	13,796
	Effect of dilutive common stock options outstanding	83	150	78	158
	Effect of dilutive restricted stock units outstanding	312	352	331	363
	Shares used in diluted per share computation	13,993	14,196	14,047	14,317
	There were no options excluded from the diluted per share calculations for the three and nine months ended September 27, 2013 and September 28, 2012.

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 27, 2013
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 $1,557,000 and $1,568,000 during the three months ended September 27, 2013 and September 28, 2012, respectively.  For the nine months ended September 27, 2013 and September 28, 2012, the Company recorded stock-based compensation expense associated with accrued bonus awards of $4,695,000 and $4,701,000, 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 $844,000 and $1,018,000 during the three months ended September 27, 2013 and September 28, 2012, respectively.  The Company recorded stock-based compensation expense associated with the unvested restricted stock unit awards of $5,169,000 and $4,757,000 during the nine months ended September 27, 2013 and September 28, 2012, 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 $100,000 and $162,000 during the three months ended September 27, 2013 and September 28, 2012, respectively, associated with stock option grants.  The Company recorded stock-based compensation expense of $969,000 and $474,000 during the nine months ended September 27, 2013 and September 28, 2012, 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
	Sep. 27, 2013
Equity [Abstract]	'
Treasury Stock	'
	Note 5:  Treasury Stock
	On May 25, 2011, the Company’s Board of Directors authorized $35,000,000 for the repurchase of the Company’s common stock.  On February 9, 2012, the Company’s Board of Directors authorized an additional $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.
	The Company repurchased 388,604 shares of its common stock for $21,211,000 during the nine months ended September 27, 2013.  The Company repurchased 404,948 shares of its common stock for $19,437,000 during the nine months ended September 28, 2012.  As of September 27, 2013, the Company had remaining authorization under its stock repurchase plans of $34,800,000 to repurchase shares of common stock.
	The Company reissued 282,010 shares of its treasury stock with a cost of approximately $5,711,000 to settle restricted stock unit awards, stock options, dividends and purchases under the Employee Stock Purchase Plan during the nine months ended September 27, 2013.  The Company reissued 292,316 shares of its treasury stock with a cost of $7,902,000 to settle restricted stock unit awards, stock options and purchases under the Employee Stock Purchase Plan during the nine months ended September 28, 2012.

Deferred_Compensation_Plan

Deferred Compensation Plan	9 Months Ended
	Sep. 27, 2013
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 September 27, 2013 and December 28, 2012, the invested amounts under the plan totaled $35,499,000 and $27,089,000, 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 September 27, 2013 and December 28, 2012, vested amounts due under the plan totaled $35,431,000 and $26,984,000, respectively.  Changes in the liability are recorded as adjustments to compensation expense. During the three months ended September 27, 2013 and September 28, 2012, the Company recognized compensation expense of $1,893,000 and $1,094,000, respectively, as a result of increases in the fair value of the trust assets with the same amount being recorded as income in other income, net.  During the nine months ended September 27, 2013 and September 28, 2012, the Company recognized compensation expense of $4,128,000 and $2,027,000, respectively, as a result of increases in the fair value of the trust assets with the same amount being recorded as income in other income, net.

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	9 Months Ended
	Sep. 27, 2013
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)	September 27,		September 28,
		2013		2012
	Cash paid during period:
	Income taxes	$	17,027	$	16,026
	Non-cash investing and financing activities:
	Unrealized loss on short-term investments	$	-25	$	-5
	Vested stock unit awards issued to settle accrued bonuses	$	5,807	$	5,343

Accounts_Receivable_Net

Accounts Receivable, Net	9 Months Ended
	Sep. 27, 2013
Receivables [Abstract]	'
Accounts Receivable, Net	'
	Note 8: Accounts Receivable, Net
	At September 27, 2013 and December 28, 2012, accounts receivable, net, was comprised of the following:
		September 27,		December 28,
	(In thousands)	2013		2012
	Billed accounts receivable	$	52,733	$	54,653
	Unbilled accounts receivable		32,216		33,374
	Allowance for doubtful accounts		-2,772		-2,666
	Total accounts receivable, net	$	82,177	$	85,361

Segment_Reporting

Segment Reporting	9 Months Ended
	Sep. 27, 2013
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 September 27, 2013 and September 28, 2012 follows:
	Revenues
		Three Months Ended				Nine Months Ended
	(In thousands)	September 27,		September 28,		September 27,		September 28,
		2013		2012		2013		2012
	Engineering and other scientific	$	56,395	$	53,071	$	163,353	$	158,784
	Environmental and health		18,836		20,227		60,043		60,923
	Total revenues	$	75,231	$	73,298	$	223,396	$	219,707
	Operating Income
		Three Months Ended				Nine Months Ended
	(In thousands)	September 27,		September 28,		September 27,		September 28,
		2013		2012		2013		2012
	Engineering and other scientific	$	18,115	$	16,217	$	51,747	$	47,573
	Environmental and health		5,624		6,933		19,104		20,722
	Total segment operating income		23,739		23,150		70,851		68,295
	Corporate operating expense		-8,579		-8,422		-27,247		-24,390
	Total operating income	$	15,160	$	14,728	$	43,604	$	43,905
	Capital Expenditures
		Three Months Ended				Nine Months Ended
	(In thousands)	September 27,		September 28,		September 27,		September 28,
		2013		2012		2013		2012
	Engineering and other scientific	$	664	$	1,103	$	3,924	$	2,039
	Environmental and health		41		174		110		348
	Total segment capital expenditures		705		1,277		4,034		2,387
	Corporate capital expenditures		187		206		559		1,038
	Total capital expenditures	$	892	$	1,483	$	4,593	$	3,425
	Depreciation and Amortization
		Three Months Ended				Nine Months Ended
	(In thousands)	September 27,		September 28,		September 27,		September 28,
		2013		2012		2013		2012
	Engineering and other scientific	$	813	$	677	$	2,269	$	2,061
	Environmental and health		76		72		221		209
	Total segment depreciation and		889		749		2,490		2,270
	amortization
	Corporate depreciation and		394		384		1,177		1,189
	amortization
	Total depreciation and	$	1,283	$	1,133	$	3,667	$	3,459
	amortization
	No single customer comprised more than 10% of the Company’s revenues during the three or nine months ended September 27, 2013 and September 28, 2012.  No single customer comprised more than 10% of the Company’s accounts receivable at September 27, 2013.  Agencies of the U.S. federal government comprised 11% of the Company’s accounts receivable at December 28, 2012.

Goodwill

Goodwill	9 Months Ended
	Sep. 27, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill	'
	Note 10: Goodwill
	Below is a breakdown of goodwill reported by segment as of September 27, 2013:
		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 nine months ended September 27, 2013.

Contingencies

Contingencies	9 Months Ended
	Sep. 27, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Contingencies	'
	Note 11: Contingencies
	The Company is party to a lawsuit arising from the Company’s hiring of employees from another consulting firm.  Their former employer alleges that the Company aided and abetted the employees’ breach of duties owed to their former employer, wrongfully interfered with the former employer’s economic relationships, and breached a software license agreement.  The lawsuit also alleges that the Company misappropriated the former employer’s trade secrets and violated unfair trade practice laws.  The lawsuit does not allege a specific dollar amount of damages. The case is currently in discovery and no trial date has been set.  The Company intends to vigorously defend itself.  Although the Company’s ultimate liability in this matter cannot be determined based on the information currently available, the Company believes, after consultation with legal counsel, the ultimate resolution of this claim will not have a material adverse effect on its financial condition.
	In addition to the above matter, the Company is a party to various other 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.  All legal costs associated with litigation are expensed as incurred.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 27, 2013
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 September 27, 2013:
			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)		$	56,938	$	56,938	$	-	$	-
	Fixed income available
	for sale securities (2)			13,296		-		13,296		-
	Fixed income trading
	securities held in deferred
	compensation plan (3)			9,921		9,921		-		-
	Equity trading securities
	held in deferred
	compensation plan (3)			25,578		25,578		-		-
	Total		$	105,733	$	92,437	$	13,296	$	-
	Liabilities
	Deferred compensation
	plan (4)			35,431		35,431		-		-
	Total		$	35,431	$	35,431	$	-	$	-
	-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 other current assets and deferred compensation plan assets on the Company’s unaudited condensed consolidated balance sheet.
	-4	Included in accrued liabilities 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 December 28, 2012:
			Fair Value Measurements at Reporting Date Using
	(In thousands)		Total		Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable Inputs		Unobservable Inputs
					Identical Assets		(Level 2)		(Level 3)
					(Level 1)
	Assets
	Money market
	securities (1)		$	49,134	$	49,134	$	-	$	-
	Fixed income available
	for sale securities (2)			20,881		-		20,881		-
	Fixed income trading
	securities held in deferred
	compensation plan (3)			9,911		9,911		-		-
	Equity trading securities
	held in deferred
	compensation plan (3)			17,178		17,178		-		-
	Total		$	97,104	$	76,223	$	20,881	$	-
	Liabilities
	Deferred compensation
	plan (4)			26,984		26,984		-		-
	Total		$	26,984	$	26,984	$	-	$	-
	-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 other current assets and deferred compensation plan assets on the Company’s consolidated balance sheet.
	-4	Included in accrued liabilities 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 September 27, 2013:
				Amortized	Unrealized			Unrealized		Estimated
	(In thousands)		Cost		Gains		Losses		Fair Value
	Classified as current assets:
	Cash		$	64,809	$	-	$	-	$	64,809
	Cash equivalents:
	Money market securities			56,938		-		-		56,938
	Total cash equivalents			56,938		-		-		56,938
	Total cash and cash equivalents			121,747		-		-		121,747
	Short-term investments:
	State and municipal bonds			13,299		3		-6		13,296
	Total short-term investments			13,299		3		-6		13,296
	Total cash, cash equivalents
	and short-term investments		$	135,046	$	3	$	-6	$	135,043
	There were no securities in a continuous unrealized loss position for more than 12 months as of September 27, 2013.
	Cash, cash equivalents and short-term investments consisted of the following as of December 28, 2012:
				Amortized		Unrealized		Unrealized		Estimated
	(In thousands)		Cost		Gains		Losses		Fair Value
	Classified as current assets:
	Cash		$	64,134	$	-	$	-	$	64,134
	Cash equivalents:
	Money market securities			49,134		-		-		49,134
	Total cash equivalents			49,134		-		-		49,134
	Total cash and cash equivalents			113,268		-		-		113,268
	Short-term investments:
	State and municipal bonds			20,841		41		-1		20,881
	Total short-term investments			20,841		41		-1		20,881
	Total cash, cash equivalents
	and short-term investments		$	134,109	$	41	$	-1	$	134,149
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 September 27, 2013:
			Amortized		Estimated
	(In thousands)		Cost		Fair Value
	Due within one year		$	6,069	$	6,066
	Due between one and two years			6,357		6,357
	Due between two and three years			873		873
	Total		$	13,299	$	13,296

Net_Income_Per_Share_Tables

Net Income Per Share (Tables)	9 Months Ended
	Sep. 27, 2013
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)	September 27,	September 28,	September 27,	September 28,
		2013	2012	2013	2012
	Shares used in basic per share computation	13,598	13,694	13,638	13,796
	Effect of dilutive common stock options outstanding	83	150	78	158
	Effect of dilutive restricted stock units outstanding	312	352	331	363
	Shares used in diluted per share computation	13,993	14,196	14,047	14,317

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 27, 2013
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)	September 27,		September 28,
		2013		2012
	Cash paid during period:
	Income taxes	$	17,027	$	16,026
	Non-cash investing and financing activities:
	Unrealized loss on short-term investments	$	-25	$	-5
	Vested stock unit awards issued to settle accrued bonuses	$	5,807	$	5,343

Accounts_Receivable_Net_Tables

Accounts Receivable, Net (Tables)	9 Months Ended
	Sep. 27, 2013
Receivables [Abstract]	'
Accounts Receivable, Net	'
	At September 27, 2013 and December 28, 2012, accounts receivable, net, was comprised of the following:
		September 27,		December 28,
	(In thousands)	2013		2012
	Billed accounts receivable	$	52,733	$	54,653
	Unbilled accounts receivable		32,216		33,374
	Allowance for doubtful accounts		-2,772		-2,666
	Total accounts receivable, net	$	82,177	$	85,361

Segment_Reporting_Tables

Segment Reporting (Tables)	9 Months Ended
	Sep. 27, 2013
Disclosure Segment Information [Abstract]	'
Segment Reporting Information, by Segment	'
	Segment information for the three and nine months ended September 27, 2013 and September 28, 2012 follows:
	Revenues
		Three Months Ended				Nine Months Ended
	(In thousands)	September 27,		September 28,		September 27,		September 28,
		2013		2012		2013		2012
	Engineering and other scientific	$	56,395	$	53,071	$	163,353	$	158,784
	Environmental and health		18,836		20,227		60,043		60,923
	Total revenues	$	75,231	$	73,298	$	223,396	$	219,707
	Operating Income
		Three Months Ended				Nine Months Ended
	(In thousands)	September 27,		September 28,		September 27,		September 28,
		2013		2012		2013		2012
	Engineering and other scientific	$	18,115	$	16,217	$	51,747	$	47,573
	Environmental and health		5,624		6,933		19,104		20,722
	Total segment operating income		23,739		23,150		70,851		68,295
	Corporate operating expense		-8,579		-8,422		-27,247		-24,390
	Total operating income	$	15,160	$	14,728	$	43,604	$	43,905
	Capital Expenditures
		Three Months Ended				Nine Months Ended
	(In thousands)	September 27,		September 28,		September 27,		September 28,
		2013		2012		2013		2012
	Engineering and other scientific	$	664	$	1,103	$	3,924	$	2,039
	Environmental and health		41		174		110		348
	Total segment capital expenditures		705		1,277		4,034		2,387
	Corporate capital expenditures		187		206		559		1,038
	Total capital expenditures	$	892	$	1,483	$	4,593	$	3,425
	Depreciation and Amortization
		Three Months Ended				Nine Months Ended
	(In thousands)	September 27,		September 28,		September 27,		September 28,
		2013		2012		2013		2012
	Engineering and other scientific	$	813	$	677	$	2,269	$	2,061
	Environmental and health		76		72		221		209
	Total segment depreciation and		889		749		2,490		2,270
	amortization
	Corporate depreciation and		394		384		1,177		1,189
	amortization
	Total depreciation and	$	1,283	$	1,133	$	3,667	$	3,459
	amortization

Goodwill_Tables

Goodwill (Tables)	9 Months Ended
	Sep. 27, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Breakdown of Goodwill Reported by Segment	'
	Below is a breakdown of goodwill reported by segment as of September 27, 2013:
		Environmental		Engineering and
	(In thousands)	and health		other scientific		Total
	Goodwill	$	8,099	$	508	$	8,607

Basis_Of_Presentation_Addition

Basis Of Presentation - Additional Information (Detail) (USD $)	0 Months Ended			0 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jul. 22, 2013	Apr. 16, 2013	23-May-06	Oct. 15, 2013
				Subsequent Event
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	$0.15	$0.15	'	$0.15

Assets_and_Liabilities_Measure

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (Fair Value, Measurements, Recurring, USD $)	Sep. 27, 2013		Dec. 28, 2012
In Thousands, unless otherwise specified
Assets	'		'
Money market securities	$56,938	[1]	$49,134	[2]
Total	105,733		97,104
Liabilities	'		'
Deferred compensation plan	35,431	[3]	26,984	[4]
Total	35,431		26,984
Fixed income securities	'		'
Assets	'		'
Fixed income available for sale securities	13,296	[5]	20,881	[6]
Fixed income trading securities held in deferred compensation plan	9,921	[7]	9,911	[8]
Equity securities	'		'
Assets	'		'
Equity trading securities held in deferred compensation plan	25,578	[7]	17,178	[8]
Fair Value, Inputs, Level 1	'		'
Assets	'		'
Money market securities	56,938	[1]	49,134	[2]
Total	92,437		76,223
Liabilities	'		'
Deferred compensation plan	35,431	[3]	26,984	[4]
Total	35,431		26,984
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	9,921	[7]	9,911	[8]
Fair Value, Inputs, Level 1 | Equity securities	'		'
Assets	'		'
Equity trading securities held in deferred compensation plan	25,578	[7]	17,178	[8]
Fair Value, Inputs, Level 2	'		'
Assets	'		'
Money market securities	0	[1]	0	[2]
Total	13,296		20,881
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	13,296	[5]	20,881	[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 liabilities and deferred compensation on the Companybs unaudited condensed consolidated balance sheet.
[4]	Included in accrued liabilities 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 other current assets and deferred compensation plan assets on the Companybs unaudited condensed consolidated balance sheet.
[8]	Included in other current 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 $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Dec. 28, 2012
Fair Value Measurements [Line Items]	'	'
Amortized Cost	$135,046	$134,109
Unrealized Gains	3	41
Unrealized Losses	-6	-1
Estimated Fair Value	135,043	134,149
Cash	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	64,809	64,134
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	64,809	64,134
Money market securities	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	56,938	49,134
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	56,938	49,134
Total cash equivalents	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	56,938	49,134
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	56,938	49,134
Total cash and cash equivalents	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	121,747	113,268
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	121,747	113,268
State and municipal bonds	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	13,299	20,841
Unrealized Gains	3	41
Unrealized Losses	-6	-1
Estimated Fair Value	13,296	20,881
Total short-term investments	'	'
Fair Value Measurements [Line Items]	'	'
Amortized Cost	13,299	20,841
Unrealized Gains	3	41
Unrealized Losses	-6	-1
Estimated Fair Value	$13,296	$20,881

Summarizes_Cost_And_Estimated_

Summarizes Cost And Estimated Fair Value Of Short Term Fixed Income Securities (Detail) (USD $)	Sep. 27, 2013	Dec. 28, 2012
In Thousands, unless otherwise specified
Fair Value Measurements [Line Items]	'	'
Due within one year, Amortized Cost	$6,069	'
Due between one and two years, Amortized Cost	6,357	'
Due between two and three years, Amortized Cost	873	'
Total Amortized Cost	13,299	'
Due within one year, Estimated FairValue	6,066	'
Due between one and two years, Estimated FairValue	6,357	'
Due between two and three years, Estimated FairValue	873	'
Total Estimated FairValue	$13,296	$20,881

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	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
Schedule Of Earnings Per Share Basic And Diluted [Line Items]	'	'	'	'
Shares used in basic per share computation	13,598	13,694	13,638	13,796
Shares used in diluted per share computation	13,993	14,196	14,047	14,317
Restricted Stock Units (RSUs)	'	'	'	'
Schedule Of Earnings Per Share Basic And Diluted [Line Items]	'	'	'	'
Effect of dilutive stock outstanding	312	352	331	363
Employee Stock Option	'	'	'	'
Schedule Of Earnings Per Share Basic And Diluted [Line Items]	'	'	'	'
Effect of dilutive stock outstanding	83	150	78	158

Stock_Based_Compensation_Addit

Stock Based Compensation - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
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 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	'
Vested Restricted Stock Awards	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock based compensation expense	$1,557,000	$1,568,000	$4,695,000	$4,701,000
Stock based compensation, holding period	'	'	'4 years	'
Restricted Stock Units (RSUs) | Minimum	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Recipient age to expense award on grant date	'	'	'59 years 6 months	'
Unvested Restricted Stock Awards	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock based compensation expense	844,000	1,018,000	5,169,000	4,757,000
Stock based compensation, vesting period	'	'	'4 years	'
Employee Stock Option	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock based compensation expense	$100,000	$162,000	$969,000	$474,000
Vesting percentage of stock options granted per year	'	'	25.00%	'
Stock based compensation, vesting period	'	'	'4 years	'

Treasury_Stock_Additional_Info

Treasury Stock - Additional Information (Detail) (USD $)	0 Months Ended			9 Months Ended
	Feb. 15, 2013	Feb. 09, 2012	25-May-11	Sep. 27, 2013	Sep. 28, 2012
Equity, Class of Treasury Stock [Line Items]	'	'	'	'	'
Amount of common stock approved for repurchase	$35,000,000	$35,000,000	$35,000,000	'	'
Repurchase of common stock (in shares)	'	'	'	388,604	404,948
Repurchase of common stock	'	'	'	21,211,000	19,437,000
Remaining authorized amount for repurchase of common stock	'	'	'	34,800,000	'
Treasury stock reissued to settle restricted stock unit awards, stock options and purchases under Employee Stock Purchase Plan (in shares)	'	'	'	282,010	292,316
Treasury stock reissued to settle restricted stock unit awards, stock options and purchases under Employee Stock Purchase Plan	'	'	'	$5,711,000	$7,902,000

Deferred_Compensation_Plan_Add

Deferred Compensation Plan - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012	Dec. 28, 2012
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]	'	'	'	'	'
Deferred compensation plan invested amounts	$35,499,000	'	$35,499,000	'	$27,089,000
Deferred compensation plan vested amounts due	35,431,000	'	35,431,000	'	26,984,000
Change in market value of trust assets	$1,893,000	$1,094,000	$4,128,000	$2,027,000	'
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	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
Cash paid during period:	'	'	'	'
Income taxes	'	'	$17,027	$16,026
Non-cash investing and financing activities:	'	'	'	'
Unrealized loss on short-term investments	-3	-17	-25	-5
Vested stock unit awards issued to settle accrued bonuses	'	'	$5,807	$5,343

Accounts_receivable_net_Detail

Accounts receivable, net (Detail) (USD $)	Sep. 27, 2013	Dec. 28, 2012
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Allowance for doubtful accounts	($2,772)	($2,666)
Total accounts receivable, net	82,177	85,361
Billed accounts receivable	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts receivable	52,733	54,653
Unbilled accounts receivable	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Accounts receivable	$32,216	$33,374

Segment_Information_Detail

Segment Information (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 27, 2013	Sep. 28, 2012	Sep. 27, 2013	Sep. 28, 2012
Segment Reporting Information [Line Items]	'	'	'	'
Revenues	$75,231	$73,298	$223,396	$219,707
Operating income	15,160	14,728	43,604	43,905
Capital expenditures	892	1,483	4,593	3,425
Depreciation and amortization	1,283	1,133	3,667	3,459
Engineering and other scientific	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenues	56,395	53,071	163,353	158,784
Operating income	18,115	16,217	51,747	47,573
Capital expenditures	664	1,103	3,924	2,039
Depreciation and amortization	813	677	2,269	2,061
Environmental and health	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenues	18,836	20,227	60,043	60,923
Operating income	5,624	6,933	19,104	20,722
Capital expenditures	41	174	110	348
Depreciation and amortization	76	72	221	209
Operating segments	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Operating income	23,739	23,150	70,851	68,295
Capital expenditures	705	1,277	4,034	2,387
Depreciation and amortization	889	749	2,490	2,270
Corporate	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Operating income	-8,579	-8,422	-27,247	-24,390
Capital expenditures	187	206	559	1,038
Depreciation and amortization	$394	$384	$1,177	$1,189

Segment_Reporting_Additional_I

Segment Reporting - Additional Information (Detail)	9 Months Ended
	Sep. 27, 2013	Dec. 28, 2012
		United States Federal Government Agencies
Segment Reporting Information [Line Items]	'	'
Number of operating segments	2	'
Percentage of account receivable	'	11.00%

Breakdown_of_Goodwill_Reported

Breakdown of Goodwill Reported by Segment (Detail) (USD $)	Sep. 27, 2013	Dec. 28, 2012
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	'