Forrester Research (FORR) 10-Q 12 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Nov. 07, 2013
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Entity Registrant Name	'FORRESTER RESEARCH, INC.	'
Entity Central Index Key	'0001023313	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	19,753,000

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current Assets:	'	'
Cash and cash equivalents	$70,700	$98,810
Marketable investments (Note 2)	86,961	134,876
Accounts receivable, net	37,009	74,623
Deferred commissions	8,408	9,410
Prepaid expenses and other current assets	18,645	18,978
Total current assets	221,723	336,697
Long-term marketable investments (Note 2)	9,092	8,970
Property and equipment, net	41,058	46,300
Goodwill	79,493	78,954
Intangible assets, net	6,296	7,920
Other assets	11,166	8,809
Total assets	368,828	487,650
Current Liabilities:	'	'
Accounts payable	918	772
Accrued expenses and other current liabilities	25,184	30,078
Deferred revenue	125,787	150,495
Total current liabilities	151,889	181,345
Non-current liabilities	8,972	9,433
Total liabilities	160,861	190,778
Commitments	'	'
Stockholders' Equity (Note 6):	'	'
Preferred stock, $.01 par value Authorized - 500 shares, issued and outstanding - none	'	'
Common stock, $.01 par value Authorized - 125,000 shares Issued - 20,389 and 31,451 as of September 30, 2013 and December 31, 2012, respectively Outstanding - 19,896 and 22,293 as of September 30, 2013 and December 31, 2012, respectively	204	315
Additional paid-in capital	105,396	389,362
Retained earnings	118,814	117,450
Treasury stock - 493 and 9,158 as of September 30, 2013 and December 31, 2012, respectively, at cost	-17,071	-210,843
Accumulated other comprehensive income	624	588
Total stockholders' equity	207,967	296,872
Total liabilities and stockholders' equity	$368,828	$487,650

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Per Share data, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	500	500
Preferred stock, shares issued	'	'
Preferred stock, shares outstanding	'	'
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	125,000	125,000
Common stock, shares issued	20,389	31,451
Common stock, shares outstanding	19,896	22,293
Treasury stock, shares	493	9,158

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:	'	'	'	'
Research services	$49,855	$50,509	$151,445	$151,145
Advisory services and other	19,960	18,264	68,684	66,725
Total revenues	69,815	68,773	220,129	217,870
Operating expenses:	'	'	'	'
Cost of services and fulfillment	27,584	25,736	85,397	82,502
Selling and marketing	25,771	24,309	79,617	75,709
General and administrative	9,310	8,720	27,217	27,124
Depreciation	2,292	2,262	6,954	6,510
Amortization of intangible assets	557	579	1,670	1,779
Reorganization costs	'	37	1,905	1,431
Total operating expenses	65,514	61,643	202,760	195,055
Income from operations	4,301	7,130	17,369	22,815
Other income (expense), net	-71	357	560	896
Gains (losses) on investments, net	18	755	-84	898
Income before income taxes	4,248	8,242	17,845	24,609
Income tax provision (benefit)	1,813	-2,468	7,056	3,191
Net income	$2,435	$10,710	$10,789	$21,418
Basic income per common share	$0.12	$0.48	$0.51	$0.95
Diluted income per common share	$0.12	$0.47	$0.50	$0.93
Basic weighted average common shares outstanding	20,117	22,398	21,226	22,573
Diluted weighted average common shares outstanding	20,665	22,858	21,690	23,018
Cash dividends declared per common share	$0.15	$0.14	$0.45	$0.42

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Net income	$2,435	$10,710	$10,789	$21,418
Other comprehensive income, net of taxes:	'	'	'	'
Cumulative translation adjustments	1,560	7,197	221	6,865
Changes in market value of investments:	'	'	'	'
Unrealized gain (loss), net of taxes (benefits) of $143 and $188 for the three months ended September 30, 2013 and 2012, and $(98) and $354 for the nine months ended September 30, 2013 and 2012	238	291	-202	624
Less: reclassification adjustment for net (gains) losses realized in net income, net of taxes of $4 and $2 for the three months ended September 30, 2013 and 2012, and $(11) and $12 for the nine months ended September 30, 2013 and 2012	-7	-3	17	-17
Net change in market value of investments	231	288	-185	607
Other comprehensive income	1,791	7,485	36	7,472
Comprehensive income	$4,226	$18,195	$10,825	$28,890

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Taxes (benefits) on unrealized gain	$143	$188	($98)	$354
Taxes on reclassification adjustment	$4	$2	($11)	$12

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:	'	'
Net income	$10,789	$21,418
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation	6,954	6,510
Amortization of intangible assets	1,670	1,779
Net (gains) losses from investments	84	-898
Deferred income taxes	-6,461	-9,851
Stock-based compensation	4,588	3,921
Amortization of premium on investments	1,809	2,144
Foreign currency losses	248	382
Changes in assets and liabilities, net of acquisitions	'	'
Accounts receivable	37,570	37,196
Deferred commissions	1,002	4,127
Prepaid expenses and other current assets	3,683	3,991
Accounts payable	116	-318
Accrued expenses and other liabilities	-4,698	-4,327
Deferred revenue	-25,002	-23,308
Net cash provided by operating activities	32,352	42,766
Cash flows from investing activities:	'	'
Purchases of property and equipment	-2,049	-4,388
Purchases of marketable investments	-39,636	-85,211
Proceeds from sales and maturities of marketable investments	85,398	73,055
Change in restricted cash	'	946
Other investing activity	134	66
Net cash provided by (used in) investing activities	43,847	-15,532
Cash flows from financing activities:	'	'
Dividends paid on common stock	-9,425	-9,481
Repurchases of common stock	-109,193	-26,187
Proceeds from issuance of common stock under employee equity incentive plans	14,506	8,538
Excess tax benefits from stock-based compensation	687	401
Payment of deferred acquisition consideration	-900	-864
Net cash used in financing activities	-104,325	-27,593
Effect of exchange rate changes on cash and cash equivalents	16	212
Net decrease in cash and cash equivalents	-28,110	-147
Cash and cash equivalents, beginning of period	98,810	81,047
Cash and cash equivalents, end of period	$70,700	$80,900

Interim_Consolidated_Financial

Interim Consolidated Financial Statements	9 Months Ended
	Sep. 30, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Interim Consolidated Financial Statements	'
	Note 1 — Interim Consolidated Financial Statements
	Basis of Presentation
	The accompanying unaudited interim consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for reporting on Form 10-Q. Accordingly, certain information and footnote disclosures required for complete financial statements are not included herein. The year-end balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America. It is recommended that these financial statements be read in conjunction with the consolidated financial statements and related notes that appear in the Forrester Research, Inc. (“Forrester”) Annual Report on Form 10-K for the year ended December 31, 2012. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation of the financial position, results of operations, and cash flows as of the dates and for the periods presented have been included. The results of operations for the three and nine months ended September 30, 2013 may not be indicative of the results for the year ending December 31, 2013, or any other period.
	Fair Value Measurements
	The carrying amounts reflected in the Consolidated Balance Sheets for cash and cash equivalents, accounts receivable, accounts payable, and accrued expenses approximate fair value due to their short-term maturities. See Note 2 – Marketable Investments for the fair value of the Company’s marketable investments.
	Revision of Prior Period Financial Statements
	During the quarter ended September 30, 2013, the Company identified certain prior period errors that affected the interim and annual periods in the years ended December 31, 2012 and 2011, as well as the interim periods in the six months ended June 30, 2013. The Company has reflected in the financial information included in this Note the correction of all identified prior period errors in the periods in which they originated. The prior period errors relate to:
		•		An adjustment of $0.8 million for the three and six months ended June 30, 2013 to increase the amount of research services revenue related to recognition of revenue for the event ticket included in the Company’s RoleView and Forrester Leadership Board subscription products. Based on the identification of this error, the Company reassessed its historical calculations and identified a required change in its methodology for the accounting for an insignificant amount of contract modifications during this period that resulted in an increase (decrease) to revenue for each of the periods is as follows: ($0.1) million and $0.1 million for the three months ended March 31, 2012 and September 30, 2012, respectively, and $0.1 million for the year ended December 31, 2011. This error has been reflected in deferred revenue in the revised consolidated balance sheet and statement of cash flows presented below.
		•		Adjustments to the Company’s share of operating results in one of the technology-related investment funds in which the Company holds an interest, which adjustments are principally a result of information received by the Company from the fund after the applicable reporting periods. The Company records a portion of the fund’s operating results, based on the Company’s ownership interest in the fund, as investment gains (losses). The adjustments to the gains (losses) on investments for each period is as follows: ($0.1) million and $0.1 million for the three months ended March 31, 2013 and June 30, 2013, respectively; $0.6 million and ($0.1) million for the three months ended September 30, 2012 and December 31, 2012, respectively; and $0.5 million and ($1.4) million for the years ended December 31, 2012 and 2011, respectively. This error has been reflected in other assets in the revised consolidated balance sheet and in net (gains) losses from investments in the revised statement of cash flows presented below.
		•		Adjustments to revenue for historical insignificant variances in deferred revenue for reconciling items between the Company’s general ledger and sub-ledger system. The increase (decrease) to revenue for each of the periods is as follows: ($0.1) million for the three months ended March 31, 2013; ($0.2) million, $0.2 million and $0.1 million for the three months ended June 30, 2012, September 30, 2012 and December 31, 2012, respectively; and $0.1 million and ($0.4) million for the years ended December 31, 2012 and 2011, respectively. This error has been reflected in deferred revenue in the revised consolidated balance sheet and statement of cash flows presented below.
		•		Adjustments within the year ended December 31, 2012 for the improper capitalization of software development costs during the three months ended June 30, 2012 and September 30, 2012. These errors were corrected in the three months ended December 31, 2012 in the previously filed financial statements. The increase (decrease) in general and administrative expense for each of the periods is as follows: $0.2 million, $0.3 million and ($0.5) million for the three months ended June 30, 2012, September 30, 2012 and December 31, 2012, respectively. This error has been reflected in purchases of property and equipment in the revised consolidated statement of cash flows presented below.
	In evaluating whether the Company’s previously issued consolidated financial statements were materially misstated, the Company considered the guidance in ASC Topic 250, Accounting Changes and Error Corrections, ASC Topic 250-10-S99-1, Assessing Materiality, and ASC Topic 250-10-S99-2, Considering the Effects of Prior Year Misstatements when Quantifying Misstatements in Current Year Financial Statements. The Company concluded that these errors were not material individually or in the aggregate to any of the prior reporting periods, and therefore, amendments of previously filed reports are not required. As such, the revisions for prior period corrections are reflected in the financial information for the applicable prior periods and will be reflected in future filings containing such prior period financial information.
	The effects of these prior period errors on the consolidated financial statements are as follows (in thousands, except per share amounts):
	Revised Consolidated Statements of Income
			Three Months Ended March 31, 2013									Three Months Ended June 30, 2013									Six Months Ended June 30, 2013
			As			Adjustments			As			As			Adjustments			As			As			Adjustments			As
			Previously						Revised			Previously						Revised			Previously						Revised
			Reported									Reported									Reported
	Revenues:
	Research services		$	50,378		$	(100	)	$	50,278		$	50,512		$	800		$	51,312		$	100,890		$	700		$	101,590
	Advisory services and other			21,121			(38	)		21,083			27,652			(11	)		27,641			48,773			(49	)		48,724
	Total revenues			71,499			(138	)		71,361			78,164			789			78,953			149,663			651			150,314
	Income from operations			3,418			(138	)		3,280			8,999			789			9,788			12,417			651			13,068
	Gains (losses) on investments, net			(51	)		(149	)		(200	)		(51	)		149			98			(102	)		—			(102	)
	Income before income taxes			3,743			(287	)		3,456			9,203			938			10,141			12,946			651			13,597
	Income tax provision			1,402			(115	)		1,287			3,581			375			3,956			4,983			260			5,243
	Net income		$	2,341		$	(172	)	$	2,169		$	5,622		$	563		$	6,185		$	7,963		$	391		$	8,354
	Basic income per common share		$	0.1		$	—		$	0.1		$	0.26		$	0.03		$	0.29		$	0.37		$	0.01		$	0.38
	Diluted income per common share		$	0.1		$	—		$	0.1		$	0.26		$	0.02		$	0.28		$	0.36		$	0.02		$	0.38
			Nine Months Ended September 30, 2012									Three Months Ended December 31, 2012									Full Year Ended December 31, 2012
			As			Adjustments			As			As			Adjustments			As			As			Adjustments			As
			Previously						Revised			Previously						Revised			Previously						Revised
			Reported									Reported									Reported
	Revenues:
	Research services		$	151,132		$	13		$	151,145		$	51,866		$	80		$	51,946		$	202,998		$	93		$	203,091
	Advisory services and other			66,732			(7	)		66,725			23,200			15			23,215			89,932			8			89,940
	Total revenues			217,864			6			217,870			75,066			95			75,161			292,930			101			293,031
	Operating expenses:
	General and administrative			26,667			457			27,124			10,199			(457	)		9,742			36,866			—			36,866
	Total operating expenses			194,598			457			195,055			67,673			(457	)		67,216			262,271			—			262,271
	Income from operations			23,266			(451	)		22,815			7,393			552			7,945			30,659			101			30,760
	Gains (losses) on investments, net			290			608			898			(739	)		(65	)		(804	)		(449	)		543			94
	Income before income taxes			24,452			157			24,609			7,058			487			7,545			31,510			644			32,154
	Income tax provision			3,129			62			3,191			2,807			195			3,002			5,936			257			6,193
	Net income		$	21,323		$	95		$	21,418		$	4,251		$	292		$	4,543		$	25,574		$	387		$	25,961
	Basic income per common share		$	0.94		$	0.01		$	0.95		$	0.19		$	0.01		$	0.2		$	1.14		$	0.01		$	1.15
	Diluted income per common share		$	0.93		$	—		$	0.93		$	0.19		$	0.01		$	0.2		$	1.12		$	0.01		$	1.13
			Three Months Ended June 30, 2012									Six Months Ended June 30, 2012									Three Months Ended September 30, 2012
			As			Adjustments			As			As			Adjustments			As			As			Adjustments			As
			Previously						Revised			Previously						Revised			Previously						Revised
			Reported									Reported									Reported
	Revenues:
	Research services		$	51,072		$	(100	)	$	50,972		$	100,832		$	(196	)	$	100,636		$	50,300		$	209		$	50,509
	Advisory services and other			28,021			(61	)		27,960			48,521			(60	)		48,461			18,211			53			18,264
	Total revenues			79,093			(161	)		78,932			149,353			(256	)		149,097			68,511			262			68,773
	Operating expenses:
	General and administrative			8,645			148			8,793			18,256			148			18,404			8,411			309			8,720
	Total operating expenses			67,632			148			67,780			133,264			148			133,412			61,334			309			61,643
	Income from operations			11,461			(309	)		11,152			16,089			(404	)		15,685			7,177			(47	)		7,130
	Gains (losses) on investments, net			84			—			84			143			—			143			147			608			755
	Income before income taxes			11,675			(309	)		11,366			16,771			(404	)		16,367			7,681			561			8,242
	Income tax provision			3,906			(124	)		3,782			5,821			(162	)		5,659			(2,692	)		224			(2,468	)
	Net income		$	7,769		$	(185	)	$	7,584		$	10,950		$	(242	)	$	10,708		$	10,373		$	337		$	10,710
Basic income per common share		$	0.34		$	—		$	0.34		$	0.48		$	(0.01	)	$	0.47		$	0.46		$	0.02		$	0.48
Diluted income per common share		$	0.34		$	(0.01	)	$	0.33		$	0.47		$	(0.01	)	$	0.46		$	0.45		$	0.02		$	0.47
		Three Months Ended March 31, 2012									Full Year Ended December 31, 2011
		As			Adjustments			As			As			Adjustments			As
		Previously						Revised			Previously						Revised
		Reported									Reported
Revenues:
Research services		$	49,760		$	(96	)	$	49,664		$	191,648		$	(153	)	$	191,495
Advisory services and other			20,500			1			20,501			91,968			(128	)		91,840
Total revenues			70,260			(95	)		70,165			283,616			(281	)		283,335
Income from operations			4,628			(95	)		4,533			36,997			(281	)		36,716
Gains (losses) on investments, net			59			—			59			1,018			(1,417	)		(399	)
Income before income taxes			5,096			(95	)		5,001			38,645			(1,698	)		36,947
Income tax provision			1,915			(38	)		1,877			15,635			(679	)		14,956
Net income		$	3,181		$	(57	)	$	3,124		$	23,010		$	(1,019	)	$	21,991
Basic income per common share		$	0.14		$	—		$	0.14		$	1.02		$	(0.05	)	$	0.97
Diluted income per common share		$	0.14		$	(0.01	)	$	0.13		$	0.99		$	(0.04	)	$	0.95
Revised Consolidated Statements of Comprehensive Income
The consolidated statements of comprehensive income for all periods is impacted by the same amount as net income for the respective period.
Revised Consolidated Balance Sheet
		As of December 31, 2012
		As			Adjustments			As
		Previously						Revised
		Reported
Current Assets:
Prepaid expenses and other current assets		$	18,846		$	132		$	18,978
Total current assets			336,565			132			336,697
Other assets			9,123			(314	)		8,809
Total assets		$	487,832		$	(182	)	$	487,650
Current Liabilities:
Deferred revenue		$	150,479		$	16		$	150,495
Total current liabilities			181,329			16			181,345
Total liabilities			190,762			16			190,778
Retained earnings			117,648			(198	)		117,450
Total stockholders’ equity			297,070			(198	)		296,872
Total liabilities and stockholders’ equity		$	487,832		$	(182	)	$	487,650
Revised Consolidated Statements of Cash Flows
		Three Months Ended March 31, 2013									Six Months Ended June 30, 2013
		As			Adjustments			As			As			Adjustments			As
		Previously						Revised			Previously						Revised
		Reported									Reported
Cash flows from operating activities:
Net income		$	2,341		$	(172	)	$	2,169		$	7,963		$	391		$	8,354
Net (gains) losses from investments			51			149			200			102			—			102
Prepaid expenses and other current assets			1,271			(115	)		1,156			4,619			260			4,879
Deferred revenue			2,709			138			2,847			(12,955	)		(651	)		(13,606	)
Net cash provided by operating activities			35,453			—			35,453			37,231			—			37,231
		Nine Months Ended September 30, 2012									Year Ended December 31, 2012									Year Ended December 31, 2011
		As			Adjustments			As			As			Adjustments			As			As			Adjustments			As
		Previously						Revised			Previously						Revised			Previously						Revised
		Reported									Reported									Reported
Cash flows from operating activities:
Net income		$	21,323		$	95		$	21,418		$	25,574		$	387		$	25,961		$	23,010		$	(1,019	)	$	21,991
Net (gains) losses from investments			(290	)		(608	)		(898	)		449			(543	)		(94	)		(1,018	)		1,417			399
Prepaid expenses and other current assets			3,929			62			3,991			6,279			257			6,536			(7,805	)		(679	)		(8,484	)
Deferred revenue			(23,302	)		(6	)		(23,308	)		1,807			(101	)		1,706			16,364			281			16,645
Net cash provided by operating activities			43,223			(457	)		42,766			53,147			—			53,147			55,444			—			55,444
Purchases of property and equipment			(4,845	)		457			(4,388	)		(5,103	)		—			(5,103	)		(39,776	)		—			(39,776	)
Net cash provided by (used in) investing activities			(15,989	)		457			(15,532	)		(4,076	)		—			(4,076	)		(53,036	)		—			(53,036	)

Marketable_Investments

Marketable Investments	9 Months Ended
	Sep. 30, 2013
Investments Debt And Equity Securities [Abstract]	'
Marketable Investments	'
	Note 2 — Marketable Investments
	The following table summarizes the Company’s marketable investments (in thousands):
			Amortized		Gross		Gross			Market
			Cost		Unrealized		Unrealized			Value
					Gains		Losses
	September 30, 2013
	Available-for-sale securities
	State and municipal obligations		$	9,660	$	5	$	—		$	9,665
	Federal agency and corporate obligations			77,330		131		(165	)		77,296
	Total short-term available-for-sale securities			86,990		136		(165	)		86,961
	ARS, long-term			11,000		—		(1,908	)		9,092
	Total available-for-sale securities		$	97,990	$	136	$	(2,073	)	$	96,053
			Amortized		Gross		Gross			Market
			Cost		Unrealized		Unrealized			Value
					Gains		Losses
	December 31, 2012
	Available-for-sale securities
	State and municipal obligations		$	18,859	$	27	$	(14	)	$	18,872
	Federal agency and corporate obligations			115,653		380		(29	)		116,004
	Total short-term available-for-sale securities			134,512		407		(43	)		134,876
	ARS, long-term			11,000		—		(2,030	)		8,970
	Total available-for-sale securities		$	145,512	$	407	$	(2,073	)	$	143,846
	Realized gains and losses on securities are included in earnings and are determined using the specific identification method. Realized gains or losses on the sale of the Company’s federal agency, state, municipal and corporate obligations were not material in the three and nine months ended September 30, 2013 or 2012.
	The following table summarizes the maturity periods of the marketable securities in the Company’s portfolio as of September 30, 2013. In February 2008, certain auction rate securities (“ARS”) that Forrester held experienced failed auctions that limited the liquidity of these securities. These auction failures have continued through September 30, 2013. On October 30, 2013 the Company sold the entire portfolio of ARS for net proceeds of $9.1 million. The following table reflects the ARS at their contractual maturity dates of between 2024 and 2034 (in thousands).
			FY 2013		FY2014		FY2015			Thereafter		Total
	State and municipal obligations		$	2,772	$	4,821	$	2,072		$	—	$	9,665
	Federal agency and corporate obligations			7,385		25,035		28,919			15,957		77,296
	ARS			—		—		—			9,092		9,092
	Total		$	10,157	$	29,856	$	30,991		$	25,049	$	96,053
	The following table shows the gross unrealized losses and market value of Forrester’s available-for-sale securities with unrealized losses that are not deemed to be other-than-temporary, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands):
			As of September 30, 2013
			Less Than 12 Months				12 Months or Greater
			Market		Unrealized		Market			Unrealized
			Value		Losses		Value			Losses
	State and municipal bonds		$	—	$	—	$	—		$	—
	Federal agency and corporate obligations			35,843		165		—			—
	ARS			—		—		9,092			1,908
	Total		$	35,843	$	165	$	9,092		$	1,908
			As of December 31, 2012
			Less Than 12 Months				12 Months or Greater
			Market		Unrealized		Market			Unrealized
			Value		Losses		Value			Losses
	State and municipal bonds		$	9,430	$	14	$	—		$	—
	Federal agency and corporate obligations			17,716		29		—			—
	ARS			—		—		8,970			2,030
	Total		$	27,146	$	43	$	8,970		$	2,030
	Fair Value
	The Company measures certain financial assets at fair value on a recurring basis, including cash equivalents, available-for-sale securities and trading securities. The fair values of these financial assets have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements.
	Level 1 — Fair value based on quoted prices in active markets for identical assets or liabilities.
	Level 2 — Fair value based on inputs other than Level 1 inputs that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	Level 3 — Fair value based on unobservable inputs that are supported by little or no market activity and such inputs are significant to the fair value of the assets or liabilities.
	The following table represents the Company’s fair value hierarchy for its financial assets (cash equivalents and investments) measured at fair value on a recurring basis as of September 30, 2013 and December 31, 2012 (in thousands):
			As of September 30, 2013
			Level 1		Level 2		Level 3			Total
	Money market funds (1)		$	7,111	$	—	$	—		$	7,111
	State and municipal obligations			—		9,665		—			9,665
	Federal agency and corporate obligations			—		77,296		—			77,296
	ARS			—		—		9,092			9,092
	Total		$	7,111	$	86,961	$	9,092		$	103,164
			As of December 31, 2012
			Level 1		Level 2		Level 3			Total
	Money market funds (1)		$	815	$	—	$	—		$	815
	State and municipal obligations			—		18,872		—			18,872
Federal agency and corporate obligations (2)			—		148,117		—			148,117
ARS			—		—		8,970			8,970
Total		$	815	$	166,989	$	8,970		$	176,774
-1	Included in cash and cash equivalents.
-2	$32.1 million are included in cash and cash equivalents at December 31, 2012 as original maturities at the time of purchase were 90 days or less.
Level 2 assets consist of the Company’s entire portfolio of federal, state, municipal and corporate bonds, excluding those municipal bonds described below with an auction reset feature. Level 2 assets have been initially valued at the transaction price and subsequently valued, at the end of each reporting period, typically utilizing third party pricing services or other market observable data. The pricing services utilize industry standard valuation methods, including both income and market based approaches and observable market inputs to determine value. These observable market inputs include reportable trades, benchmark yields, credit spreads, broker/dealer quotes, bids, offers, current spot rates and other industry and economic events.
Level 3 assets at September 30, 2013 and December 31, 2012 consist entirely of municipal bonds with an auction reset feature (ARS). Prior to 2008, the fair value of the ARS investments approximated par value due to the frequent resets through the auction process. While the Company continues to receive interest income on its ARS investments at each interest reset date (which occurs at either seven or 35 day intervals for each security), these investments trade infrequently and therefore do not have a readily determinable market value. Interest rates on the securities ranged from 0.1% to 0.4% and 0.1% to 0.5% during the nine months ended September 30, 2013 and 2012, respectively. The Company values the ARS using a discounted cash flow model that includes unobservable inputs including estimates of future interest rates, discount rates and expected holding periods of the securities, which is considered a Level 3 valuation. Unobservable inputs included in the valuation as of September 30, 2013 include a weighted average interest rate of 1.7%, a weighted average discount rate of 4.9%, and a weighted average holding period of 8.7 years. The valuation resulted in an unrealized loss recorded in accumulated other comprehensive income in the Consolidated Balance Sheets of $1.9 million at September 30, 2013 and $2.0 million at December 31, 2012. As of September 30, 2013, the Company classified the loss as temporary due to the strong underlying credit rating of the securities and the fact that the Company, as of September 30, 2013, did not intend to sell the securities and was not likely to be required to sell the securities. The assumptions used in valuing the ARS are volatile and subject to change as the underlying sources of these assumptions and market conditions change. Significant increases or decreases in any of the valuation assumptions in isolation would result in a significant change in the fair value.
On October 22, 2013 the Company made the decision to sell its entire portfolio of ARS. On October 30, 2013 the Company completed the sale of the ARS for net proceeds of $9.1 million, resulting in a realized loss of $1.9 million that will be recognized as an investment loss in the consolidated statement of income for the three months ended December 31, 2013.
The following table provides a summary of changes in fair value of the Company’s Level 3 financial assets for the nine months ended September 30, 2013 and 2012 (in thousands):
		ARS
Balance at December 31, 2011		$	9,565
Sales			—
Gains included in other comprehensive income			224
Balance at September 30, 2012		$	9,789
		ARS
Balance at December 31, 2012		$	8,970
Sales			—
Gains included in other comprehensive income			122
Balance at September 30, 2013		$	9,092

NonMarketable_Investments

Non-Marketable Investments	9 Months Ended
	Sep. 30, 2013
Investments Debt And Equity Securities [Abstract]	'
Non-Marketable Investments	'
	Note 3 — Non-Marketable Investments
	At September 30, 2013 and December 31, 2012, the carrying value of the Company’s non-marketable investments, which were composed primarily of interests in technology-related private equity funds, was $6.2 million and $6.6 million, respectively, and is included in other assets in the Consolidated Balance Sheets.
	One of the Company’s investments, with a book value of $0.9 million and $1.2 million at September 30, 2013 and December 31, 2012, respectively, is being accounted for using the cost method and, accordingly, is valued at cost unless an other-than-temporary impairment in its value occurs. The other investments are being accounted for using the equity method as the investments are limited partnerships and the Company has an ownership interest in excess of 5% and, accordingly, the Company records its share of the investee’s operating results each period. The Company recorded a gain (loss) from its non-marketable investments of $(0.1) million during the nine months ended September 30, 2013, and $0.8 million and $0.9 million during the three and nine months ended September 30, 2012, respectively, which is included in gains (losses) on investments, net in the Consolidated Statements of Income. Gains on investments were insignificant during the three months ended September 30, 2013.
	In May 2013, the Company extended the expiration date of a cash bonus plan, originally adopted in 2000, that would pay a bonus, after the return of invested capital from certain of the Company’s investments, to certain key employees. To date, no bonuses have been paid under the plan. The plan will now automatically expire on June 30, 2015, subject to earlier expiration as provided in the plan in the event that prior to such date there are less than 10 participants in the plan or all of the Company’s invested capital (as defined in the plan) has been returned to the Company.

Reorganization

Reorganization	9 Months Ended
	Sep. 30, 2013
Restructuring And Related Activities [Abstract]	'
Reorganization	'
	Note 4 — Reorganization
	The following table rolls forward the activity in the reorganization accrual for the nine months ended September 30, 2013 (in thousands):
		Workforce
		Reduction
	Accrual at December 31, 2012	$	14
	Additions		1,905
	Cash payments		(1,655	)
	Accrual at September 30, 2013	$	264
	During the nine months ended September 30, 2013 the Company incurred $1.9 million of severance and related costs for the elimination of 31 jobs or approximately 2.5% of its workforce worldwide to streamline its operations. The accrual at September 30, 2013 is expected to be paid by the end of 2013.

Net_Income_Per_Common_Share

Net Income Per Common Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Net Income Per Common Share	'
	Note 5 — Net Income Per Common Share
	Basic net income per common share is computed by dividing net income by the basic weighted average number of common shares outstanding during the period. Diluted net income per common share is computed by dividing net income by the diluted weighted average number of common shares and common equivalent shares outstanding during the period. The weighted average number of common equivalent shares outstanding has been determined in accordance with the treasury-stock method. Common equivalent shares consist of common stock issuable on the exercise of outstanding options and vesting of restricted stock units when dilutive.
	Basic and diluted weighted average common shares are as follows (in thousands):
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
	Basic weighted average common shares outstanding		20,117		22,398		21,226		22,573
	Weighted average common equivalent shares		548		460		464		445
	Diluted weighted average common shares outstanding		20,665		22,858		21,690		23,018
	Options excluded from diluted weighted average share calculation as effect would have been anti-dilutive		608		967		700		644

Stockholders_Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Stockholders' Equity	'
	Note 6 — Stockholders’ Equity
	Equity Plans
	Stock option activity for the nine months ended September 30, 2013 is presented below (in thousands, except per share data):
		Number of			Weighted-			Weighted -			Aggregate
		Shares			Average			Average			Intrinsic
					Exercise			Remaining			Value
					Price Per			Contractual
					Share			Term (in years)
	Outstanding at December 31, 2012		1,936		$	29.03
	Granted		489			35.2
	Exercised		(524	)		25.46
	Forfeited		(69	)		32.05
	Outstanding at September 30, 2013		1,832		$	31.58			7.11		$	9,592
	Exercisable at September 30, 2013		866		$	28.73			5.14		$	6,995
	Restricted stock unit activity for the nine months ended September 30, 2013 is presented below (in thousands, except per share data):
		Number of			Weighted-
		Shares			Average
					Grant Date
					Fair Value
	Unvested at December 31, 2012		301		$	32.98
	Granted		207			34.58
	Vested or settled		(67	)		32.91
	Forfeited		(56	)		31.02
	Unvested at September 30, 2013		385		$	34.14
	Stock-Based Compensation
	Forrester recognizes the fair value of stock-based compensation in net income over the requisite service period of the individual grantee, which generally equals the vesting period. Stock-based compensation was recorded in the following expense categories (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Cost of services and fulfillment	$	1,061		$	835		$	2,708		$	2,213
	Selling and marketing		321			207			893			638
	General and administrative		478			367			987			1,070
	Total	$	1,860		$	1,409		$	4,588		$	3,921
	In 2010, the Company issued to its employees approximately 63,000 performance-based RSUs. The vesting of the RSUs was subject to performance criteria and would vest at 100% or 40% on April 1, 2013, or the RSUs could be forfeited, depending on whether specified revenue growth and certain operating margin targets related to full year 2012 performance were achieved. Based on 2012 financial performance these RSUs were forfeited. Compensation expense through the third quarter of 2011 was recognized based on an estimate of 100% vesting of the RSUs and in the fourth quarter of 2011 the Company modified its assessment of vesting to a zero percent level. The Company continued to utilize a zero percent vesting estimate through March 31, 2013.
	In 2011, the Company issued to its employees approximately 71,000 performance-based RSUs. The vesting of the RSUs is subject to performance criteria and will vest at 100% or 40% on April 1, 2014, or the RSUs could be forfeited, depending on whether specified revenue growth and certain operating margin targets related to full year 2013 performance are achieved. Compensation expense through the third quarter of 2011 was recognized based on an estimate of 100% vesting of the RSUs and in the fourth quarter of 2011 the Company modified its assessment of vesting to a zero percent level. The Company continued to utilize a zero percent vesting estimate through the nine months ended September 30, 2013.
	Forrester utilizes the Black-Scholes valuation model for estimating the fair value of stock options. Options granted under the equity incentive plans and shares subject to purchase under the employee stock purchase plan were valued using the following assumptions:
		Three Months Ended						Three Months Ended
		September 30, 2013						September 30, 2012
		Equity Incentive			Employee Stock			Equity Incentive			Employee Stock
		Plans			Purchase Plan			Plans			Purchase Plan
	Average risk-free interest rate		1.4	%		0.08	%		0.62	%		0.14	%
	Expected dividend yield		2.1	%		2.1	%		1.7	%		1.7	%
	Expected life		4.9 Years			0.5 Years			4.5 Years			0.5 Years
	Expected volatility		36	%		19	%		40	%		31	%
	Weighted average fair value	$	9.94		$	6.02		$	9.42		$	6.89
		Nine Months Ended						Nine Months Ended
		September 30, 2013						September 30, 2012
		Equity Incentive			Employee Stock			Equity Incentive			Employee Stock
		Plans			Purchase Plan			Plans			Purchase Plan
	Average risk-free interest rate		0.81	%		0.08	%		0.87	%		0.14	%
	Expected dividend yield		2.1	%		2.1	%		1.7	%		1.7	%
	Expected life		4.9 Years			0.5 Years			4.5 Years			0.5 Years
	Expected volatility		37	%		19	%		40	%		31	%
	Weighted average fair value	$	9.15		$	6.02		$	9.81		$	6.87
	Dividends
	In the nine months ended September 30, 2013, the Company declared and paid dividends of $9.4 million consisting of a $0.15 per share dividend in each of the first three quarters of 2013. In the nine months ended September 30, 2012, the Company declared and paid dividends of $9.5 million consisting of a $0.14 per share dividend in each of the first three quarters of 2012. In October 2013, the Company declared a dividend of $0.15 per share payable on December 18, 2013 to shareholders of record as of December 4, 2013.
	Treasury Stock
	Forrester’s Board of Directors has authorized an aggregate $385.0 million, including $25 million authorized in July 2013 and $50 million authorized in February 2013, to purchase common stock under the stock repurchase program. The shares repurchased may be used, among other things, in connection with Forrester’s employee and director equity incentive and purchase plans. In the nine months ended September 30, 2013, the Company repurchased approximately 3.0 million shares of common stock at an aggregate cost of approximately $109.2 million, inclusive of the repurchase of shares pursuant to the “modified Dutch auction” described below. From the inception of the program through September 30, 2013, Forrester repurchased approximately 12.2 million shares of common stock at an aggregate cost of approximately $320.0 million.
	On April 3, 2013 the Company commenced a “modified Dutch auction” self-tender offer to repurchase up to $130 million of its common stock at a price per share within the range of $32.00 to $36.00. A “modified Dutch auction” self-tender offer allows stockholders to indicate how many shares and at what price within the company’s specified range (in increments of $0.25 per share) they wish to tender. When the tender offer expired, based upon the number of shares tendered and the prices specified by the tendering stockholders, the Company determined the purchase price, which was the lowest price per share within the range that enabled the Company to purchase up to $130 million of its common stock. The tender offer expired on May 1, 2013 and the Company purchased 2,054,732 shares of its common stock on May 7, 2013 at a purchase price of $36.00 per share for an aggregate purchase price of $74.0 million, plus approximately $1.1 million of expenses related to the tender offer.
	In the nine months ended September 30, 2013, the Company retired 11.7 million shares of treasury stock. These retired shares are now included in the Company’s pool of authorized but unissued shares. The retired stock had a carrying value of approximately $303.0 million. The Company’s accounting policy upon the formal retirement of treasury stock is to deduct the par value of the retired stock from Common Stock and to reflect the excess of cost over par value as a deduction from Additional Paid-in Capital.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Note 7 — Income Taxes
	Forrester provides for income taxes on an interim basis according to management’s estimate of the effective tax rate expected to be applicable for the full fiscal year. Certain items such as changes in tax rates and tax benefits related to disqualifying dispositions of incentive stock options are treated as discrete items and are recorded in the period in which they arise.
	Income tax expense for the nine months ended September 30, 2013 was $7.1 million resulting in an effective tax rate of 39.5% for the period. Income tax expense for the nine months ended September 30, 2012 was $3.2 million resulting in an effective tax rate of 13.0% for the period. The increase in the effective tax rate during the nine months ended September 30, 2013 as compared to the prior year is primarily due to the 2012 period including a $5.5 million deferred tax benefit resulting from the settlement of a tax audit at one of the Company’s foreign subsidiaries. In addition, the 2012 period included a reduction in the reserve for uncertain tax positions as well as a credit due to a remeasurement gain of a euro-denominated deferred tax liability.

Operating_Segments

Operating Segments	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Operating Segments	'
	Note 8 — Operating Segments
	Forrester is organized into two client groups with each client group responsible for writing relevant research for the roles within the client organization on a worldwide basis. The two client groups, which are considered operating segments, are: Business Technology (“BT”) and Marketing and Strategy (“M&S”). In addition, the Company’s Events segment supports both client groups. Each client group generates revenues through sales of research, advisory and other service offerings targeted at specific roles within their targeted clients. Each client group consists of research personnel focused primarily on issues relevant to particular roles and to the day-to-day responsibilities of persons within the roles. Amounts included in the Events segment relate to the operations of the events production department. Revenue reported in the Events segment consists primarily of sponsorships and event tickets to Forrester events.
	Forrester evaluates reportable segment performance and allocates resources based on direct margin. Direct margin, as presented below, is defined as operating income excluding sales expenses, certain marketing and fulfillment expenses, stock-based compensation expense, general and administrative expenses, depreciation expense, amortization of intangible assets and reorganization costs. In the first quarter of 2013, the Company modified segment direct margin for each of the BT and M&S client groups to reflect the transfer of revenue and direct costs related to one product line from BT to M&S and to reallocate certain shared consulting costs between BT & M&S. Accordingly, the 2012 amounts have been reclassified to conform to the current presentation. The accounting policies used by the segments are the same as those used in the consolidated financial statements.
	The following tables present information about reportable segments (in thousands):
		BT		M&S		Events			Consolidated
	Three Months Ended September 30, 2013
	Revenue	$	37,659	$	31,809	$	347		$	69,815
	Direct margin		24,912		20,923		(656	)		45,179
	Selling, marketing, administrative and other expenses									(40,321	)
	Amortization of intangible assets									(557	)
	Reorganization costs									—
	Other income (expense) and gains (losses) on investments									(53	)
	Income before income taxes								$	4,248
		BT		M&S		Events			Consolidated
	Three Months Ended September 30, 2012
	Revenue	$	37,764	$	30,707	$	302		$	68,773
	Direct margin		25,966		20,203		(727	)		45,442
	Selling, marketing, administrative and other expenses									(37,696	)
	Amortization of intangible assets									(579	)
	Reorganization costs									(37	)
	Other income (expense) and gains (losses) on investments									1,112
	Income before income taxes								$	8,242
		BT		M&S		Events			Consolidated
	Nine Months Ended September 30, 2013
	Revenue	$	115,327	$	95,690	$	9,112		$	220,129
	Direct margin		78,100		62,909		3,204			144,213
	Selling, marketing, administrative and other expenses									(123,269	)
	Amortization of intangible assets									(1,670	)
	Reorganization costs									(1,905	)
	Other income (expense) and gains (losses) on investments									476
	Income before income taxes								$	17,845
		BT		M&S		Events			Consolidated
	Nine Months Ended September 30, 2012
	Revenue	$	115,470	$	92,995	$	9,405		$	217,870
	Direct margin		78,882		60,823		3,241			142,946
	Selling, marketing, administrative and other expenses									(116,921	)
	Amortization of intangible assets									(1,779	)
	Reorganization costs									(1,431	)
	Other income (expense) and gains (losses) on investments									1,794
	Income before income taxes								$	24,609

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2013
Accounting Changes And Error Corrections [Abstract]	'
Recent Accounting Pronouncements	'
	Note 9 — Recent Accounting Pronouncements
	In July 2012, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2012-02, Intangibles – Goodwill and Other (Topic 350): Testing Indefinite-Lived Intangible Assets for Impairment. This accounting standard allows an entity the option to first assess qualitative factors to determine whether it is necessary to perform a quantitative impairment test for indefinite-lived intangibles other than goodwill. Under that option, an entity would no longer be required to calculate the fair value of an indefinite-lived intangible asset unless the entity determines, based on that qualitative assessment, that it is more likely than not that the fair value of the indefinite-lived intangible asset is less than its carrying amount. This ASU was effective for annual and interim indefinite-lived intangible asset impairment tests performed for fiscal years beginning after September 15, 2012. As the Company does not have any indefinite-lived intangible assets as of September 30, 2013 other than goodwill, the adoption of this standard on January 1, 2013 did not have an impact on the Company’s consolidated financial results.
	In February 2013, the FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220): Reporting Amounts Reclassified Out of Accumulated Other Comprehensive Income. This accounting standard requires companies to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, companies are 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. This ASU is effective for reporting periods beginning after December 15, 2012. Other than requiring additional disclosures, adoption of this ASU did not have a significant impact on the Company’s consolidated financial results.

Recent_Accounting_Pronouncemen1

Recent Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2013
Accounting Changes And Error Corrections [Abstract]	'
Intangibles - Goodwill and Other	'
	In July 2012, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2012-02, Intangibles – Goodwill and Other (Topic 350): Testing Indefinite-Lived Intangible Assets for Impairment. This accounting standard allows an entity the option to first assess qualitative factors to determine whether it is necessary to perform a quantitative impairment test for indefinite-lived intangibles other than goodwill. Under that option, an entity would no longer be required to calculate the fair value of an indefinite-lived intangible asset unless the entity determines, based on that qualitative assessment, that it is more likely than not that the fair value of the indefinite-lived intangible asset is less than its carrying amount. This ASU was effective for annual and interim indefinite-lived intangible asset impairment tests performed for fiscal years beginning after September 15, 2012. As the Company does not have any indefinite-lived intangible assets as of September 30, 2013 other than goodwill, the adoption of this standard on January 1, 2013 did not have an impact on the Company’s consolidated financial results.
Reporting Amounts Reclassified Out of Accumulated Other Comprehensive Income	'
	In February 2013, the FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220): Reporting Amounts Reclassified Out of Accumulated Other Comprehensive Income. This accounting standard requires companies to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, companies are 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. This ASU is effective for reporting periods beginning after December 15, 2012. Other than requiring additional disclosures, adoption of this ASU did not have a significant impact on the Company’s consolidated financial results.

Interim_Consolidated_Financial1

Interim Consolidated Financial Statements (Tables)	9 Months Ended
	Sep. 30, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Revised Consolidated Statements of Income	'
	The effects of these prior period errors on the consolidated financial statements are as follows (in thousands, except per share amounts):
	Revised Consolidated Statements of Income
		Three Months Ended March 31, 2013									Three Months Ended June 30, 2013									Six Months Ended June 30, 2013
		As			Adjustments			As			As			Adjustments			As			As			Adjustments			As
		Previously						Revised			Previously						Revised			Previously						Revised
		Reported									Reported									Reported
	Revenues:
	Research services	$	50,378		$	(100	)	$	50,278		$	50,512		$	800		$	51,312		$	100,890		$	700		$	101,590
	Advisory services and other		21,121			(38	)		21,083			27,652			(11	)		27,641			48,773			(49	)		48,724
	Total revenues		71,499			(138	)		71,361			78,164			789			78,953			149,663			651			150,314
	Income from operations		3,418			(138	)		3,280			8,999			789			9,788			12,417			651			13,068
	Gains (losses) on investments, net		(51	)		(149	)		(200	)		(51	)		149			98			(102	)		—			(102	)
	Income before income taxes		3,743			(287	)		3,456			9,203			938			10,141			12,946			651			13,597
	Income tax provision		1,402			(115	)		1,287			3,581			375			3,956			4,983			260			5,243
	Net income	$	2,341		$	(172	)	$	2,169		$	5,622		$	563		$	6,185		$	7,963		$	391		$	8,354
	Basic income per common share	$	0.1		$	—		$	0.1		$	0.26		$	0.03		$	0.29		$	0.37		$	0.01		$	0.38
	Diluted income per common share	$	0.1		$	—		$	0.1		$	0.26		$	0.02		$	0.28		$	0.36		$	0.02		$	0.38
		Nine Months Ended September 30, 2012									Three Months Ended December 31, 2012									Full Year Ended December 31, 2012
		As			Adjustments			As			As			Adjustments			As			As			Adjustments			As
		Previously						Revised			Previously						Revised			Previously						Revised
		Reported									Reported									Reported
	Revenues:
	Research services	$	151,132		$	13		$	151,145		$	51,866		$	80		$	51,946		$	202,998		$	93		$	203,091
	Advisory services and other		66,732			(7	)		66,725			23,200			15			23,215			89,932			8			89,940
	Total revenues		217,864			6			217,870			75,066			95			75,161			292,930			101			293,031
	Operating expenses:
	General and administrative		26,667			457			27,124			10,199			(457	)		9,742			36,866			—			36,866
	Total operating expenses		194,598			457			195,055			67,673			(457	)		67,216			262,271			—			262,271
	Income from operations		23,266			(451	)		22,815			7,393			552			7,945			30,659			101			30,760
	Gains (losses) on investments, net		290			608			898			(739	)		(65	)		(804	)		(449	)		543			94
	Income before income taxes		24,452			157			24,609			7,058			487			7,545			31,510			644			32,154
	Income tax provision		3,129			62			3,191			2,807			195			3,002			5,936			257			6,193
	Net income	$	21,323		$	95		$	21,418		$	4,251		$	292		$	4,543		$	25,574		$	387		$	25,961
	Basic income per common share	$	0.94		$	0.01		$	0.95		$	0.19		$	0.01		$	0.2		$	1.14		$	0.01		$	1.15
	Diluted income per common share	$	0.93		$	—		$	0.93		$	0.19		$	0.01		$	0.2		$	1.12		$	0.01		$	1.13
		Three Months Ended June 30, 2012									Six Months Ended June 30, 2012									Three Months Ended September 30, 2012
		As			Adjustments			As			As			Adjustments			As			As			Adjustments			As
		Previously						Revised			Previously						Revised			Previously						Revised
		Reported									Reported									Reported
	Revenues:
	Research services	$	51,072		$	(100	)	$	50,972		$	100,832		$	(196	)	$	100,636		$	50,300		$	209		$	50,509
	Advisory services and other		28,021			(61	)		27,960			48,521			(60	)		48,461			18,211			53			18,264
	Total revenues		79,093			(161	)		78,932			149,353			(256	)		149,097			68,511			262			68,773
	Operating expenses:
	General and administrative		8,645			148			8,793			18,256			148			18,404			8,411			309			8,720
	Total operating expenses		67,632			148			67,780			133,264			148			133,412			61,334			309			61,643
	Income from operations		11,461			(309	)		11,152			16,089			(404	)		15,685			7,177			(47	)		7,130
	Gains (losses) on investments, net		84			—			84			143			—			143			147			608			755
	Income before income taxes		11,675			(309	)		11,366			16,771			(404	)		16,367			7,681			561			8,242
	Income tax provision		3,906			(124	)		3,782			5,821			(162	)		5,659			(2,692	)		224			(2,468	)
	Net income	$	7,769		$	(185	)	$	7,584		$	10,950		$	(242	)	$	10,708		$	10,373		$	337		$	10,710
	Basic income per common share	$	0.34		$	—		$	0.34		$	0.48		$	(0.01	)	$	0.47		$	0.46		$	0.02		$	0.48
	Diluted income per common share	$	0.34		$	(0.01	)	$	0.33		$	0.47		$	(0.01	)	$	0.46		$	0.45		$	0.02		$	0.47
		Three Months Ended March 31, 2012									Full Year Ended December 31, 2011
		As			Adjustments			As			As			Adjustments			As
		Previously						Revised			Previously						Revised
		Reported									Reported
	Revenues:
	Research services	$	49,760		$	(96	)	$	49,664		$	191,648		$	(153	)	$	191,495
	Advisory services and other		20,500			1			20,501			91,968			(128	)		91,840
	Total revenues		70,260			(95	)		70,165			283,616			(281	)		283,335
	Income from operations		4,628			(95	)		4,533			36,997			(281	)		36,716
	Gains (losses) on investments, net		59			—			59			1,018			(1,417	)		(399	)
Income before income taxes		5,096			(95	)		5,001			38,645			(1,698	)		36,947
Income tax provision		1,915			(38	)		1,877			15,635			(679	)		14,956
Net income	$	3,181		$	(57	)	$	3,124		$	23,010		$	(1,019	)	$	21,991
Basic income per common share	$	0.14		$	—		$	0.14		$	1.02		$	(0.05	)	$	0.97
Diluted income per common share	$	0.14		$	(0.01	)	$	0.13		$	0.99		$	(0.04	)	$	0.95
Revised Consolidated Statements of Comprehensive Income	'
	Revised Consolidated Statements of Comprehensive Income
	The consolidated statements of comprehensive income for all periods is impacted by the same amount as net income for the respective period.
Revised Consolidated Balance Sheet	'
	Revised Consolidated Balance Sheet
		As of December 31, 2012
		As			Adjustments			As
		Previously						Revised
		Reported
	Current Assets:
	Prepaid expenses and other current assets	$	18,846		$	132		$	18,978
	Total current assets		336,565			132			336,697
	Other assets		9,123			(314	)		8,809
	Total assets	$	487,832		$	(182	)	$	487,650
	Current Liabilities:
	Deferred revenue	$	150,479		$	16		$	150,495
	Total current liabilities		181,329			16			181,345
	Total liabilities		190,762			16			190,778
	Retained earnings		117,648			(198	)		117,450
	Total stockholders’ equity		297,070			(198	)		296,872
	Total liabilities and stockholders’ equity	$	487,832		$	(182	)	$	487,650
Revised Consolidated Statements of Cash Flows	'
	Revised Consolidated Statements of Cash Flows
		Three Months Ended March 31, 2013									Six Months Ended June 30, 2013
		As			Adjustments			As			As			Adjustments			As
		Previously						Revised			Previously						Revised
		Reported									Reported
	Cash flows from operating activities:
	Net income	$	2,341		$	(172	)	$	2,169		$	7,963		$	391		$	8,354
	Net (gains) losses from investments		51			149			200			102			—			102
	Prepaid expenses and other current assets		1,271			(115	)		1,156			4,619			260			4,879
	Deferred revenue		2,709			138			2,847			(12,955	)		(651	)		(13,606	)
	Net cash provided by operating activities		35,453			—			35,453			37,231			—			37,231
		Nine Months Ended September 30, 2012									Year Ended December 31, 2012									Year Ended December 31, 2011
		As			Adjustments			As			As			Adjustments			As			As			Adjustments			As
		Previously						Revised			Previously						Revised			Previously						Revised
		Reported									Reported									Reported
	Cash flows from operating activities:
	Net income	$	21,323		$	95		$	21,418		$	25,574		$	387		$	25,961		$	23,010		$	(1,019	)	$	21,991
	Net (gains) losses from investments		(290	)		(608	)		(898	)		449			(543	)		(94	)		(1,018	)		1,417			399
	Prepaid expenses and other current assets		3,929			62			3,991			6,279			257			6,536			(7,805	)		(679	)		(8,484	)
	Deferred revenue		(23,302	)		(6	)		(23,308	)		1,807			(101	)		1,706			16,364			281			16,645
	Net cash provided by operating activities		43,223			(457	)		42,766			53,147			—			53,147			55,444			—			55,444
	Purchases of property and equipment		(4,845	)		457			(4,388	)		(5,103	)		—			(5,103	)		(39,776	)		—			(39,776	)
	Net cash provided by (used in) investing activities		(15,989	)		457			(15,532	)		(4,076	)		—			(4,076	)		(53,036	)		—			(53,036	)

Marketable_Investments_Tables

Marketable Investments (Tables)	9 Months Ended
	Sep. 30, 2013
Investments Debt And Equity Securities [Abstract]	'
Summary of Company's Marketable Investments	'
	The following table summarizes the Company’s marketable investments (in thousands):
			Amortized		Gross		Gross			Market
			Cost		Unrealized		Unrealized			Value
					Gains		Losses
	September 30, 2013
	Available-for-sale securities
	State and municipal obligations		$	9,660	$	5	$	—		$	9,665
	Federal agency and corporate obligations			77,330		131		(165	)		77,296
	Total short-term available-for-sale securities			86,990		136		(165	)		86,961
	ARS, long-term			11,000		—		(1,908	)		9,092
	Total available-for-sale securities		$	97,990	$	136	$	(2,073	)	$	96,053
			Amortized		Gross		Gross			Market
			Cost		Unrealized		Unrealized			Value
					Gains		Losses
	December 31, 2012
	Available-for-sale securities
	State and municipal obligations		$	18,859	$	27	$	(14	)	$	18,872
	Federal agency and corporate obligations			115,653		380		(29	)		116,004
	Total short-term available-for-sale securities			134,512		407		(43	)		134,876
	ARS, long-term			11,000		—		(2,030	)		8,970
	Total available-for-sale securities		$	145,512	$	407	$	(2,073	)	$	143,846
Summary of Maturity Periods of the Marketable Securities	'
	The following table reflects the ARS at their contractual maturity dates of between 2024 and 2034 (in thousands).
			FY 2013		FY2014		FY2015			Thereafter		Total
	State and municipal obligations		$	2,772	$	4,821	$	2,072		$	—	$	9,665
	Federal agency and corporate obligations			7,385		25,035		28,919			15,957		77,296
	ARS			—		—		—			9,092		9,092
	Total		$	10,157	$	29,856	$	30,991		$	25,049	$	96,053
Summary of Gross Unrealized Losses and Market Value of Available-for-Sale Securities with Unrealized Losses	'
	The following table shows the gross unrealized losses and market value of Forrester’s available-for-sale securities with unrealized losses that are not deemed to be other-than-temporary, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands):
			As of September 30, 2013
			Less Than 12 Months				12 Months or Greater
			Market		Unrealized		Market			Unrealized
			Value		Losses		Value			Losses
	State and municipal bonds		$	—	$	—	$	—		$	—
	Federal agency and corporate obligations			35,843		165		—			—
	ARS			—		—		9,092			1,908
	Total		$	35,843	$	165	$	9,092		$	1,908
			As of December 31, 2012
			Less Than 12 Months				12 Months or Greater
			Market		Unrealized		Market			Unrealized
			Value		Losses		Value			Losses
	State and municipal bonds		$	9,430	$	14	$	—		$	—
	Federal agency and corporate obligations			17,716		29		—			—
	ARS			—		—		8,970			2,030
	Total		$	27,146	$	43	$	8,970		$	2,030
Summary of Company's Fair Value Hierarchy for its Financial Assets	'
	The following table represents the Company’s fair value hierarchy for its financial assets (cash equivalents and investments) measured at fair value on a recurring basis as of September 30, 2013 and December 31, 2012 (in thousands):
			As of September 30, 2013
			Level 1		Level 2		Level 3			Total
	Money market funds (1)		$	7,111	$	—	$	—		$	7,111
	State and municipal obligations			—		9,665		—			9,665
	Federal agency and corporate obligations			—		77,296		—			77,296
	ARS			—		—		9,092			9,092
	Total		$	7,111	$	86,961	$	9,092		$	103,164
			As of December 31, 2012
			Level 1		Level 2		Level 3			Total
	Money market funds (1)		$	815	$	—	$	—		$	815
	State and municipal obligations			—		18,872		—			18,872
	Federal agency and corporate obligations (2)			—		148,117		—			148,117
	ARS			—		—		8,970			8,970
	Total		$	815	$	166,989	$	8,970		$	176,774
	-1	Included in cash and cash equivalents.
	-2	$32.1 million are included in cash and cash equivalents at December 31, 2012 as original maturities at the time of purchase were 90 days or less.
Summary of Changes in Fair Value of Level 3 Financial Assets	'
	The following table provides a summary of changes in fair value of the Company’s Level 3 financial assets for the nine months ended September 30, 2013 and 2012 (in thousands):
			ARS
	Balance at December 31, 2011		$	9,565
	Sales			—
	Gains included in other comprehensive income			224
	Balance at September 30, 2012		$	9,789
			ARS
	Balance at December 31, 2012		$	8,970
	Sales			—
	Gains included in other comprehensive income			122
	Balance at September 30, 2013		$	9,092

Reorganization_Tables

Reorganization (Tables)	9 Months Ended
	Sep. 30, 2013
Restructuring And Related Activities [Abstract]	'
Summary of Roll Forward of Activity in Reorganization Accrual	'
	The following table rolls forward the activity in the reorganization accrual for the nine months ended September 30, 2013 (in thousands):
		Workforce
		Reduction
	Accrual at December 31, 2012	$	14
	Additions		1,905
	Cash payments		(1,655	)
	Accrual at September 30, 2013	$	264

Net_Income_Per_Common_Share_Ta

Net Income Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Summary of Basic and Diluted Weighted Average Common Shares	'
	Basic and diluted weighted average common shares are as follows (in thousands):
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
	Basic weighted average common shares outstanding		20,117		22,398		21,226		22,573
	Weighted average common equivalent shares		548		460		464		445
	Diluted weighted average common shares outstanding		20,665		22,858		21,690		23,018
	Options excluded from diluted weighted average share calculation as effect would have been anti-dilutive		608		967		700		644

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Summary of Stock Option Activity	'
	Stock option activity for the nine months ended September 30, 2013 is presented below (in thousands, except per share data):
		Number of			Weighted-			Weighted -			Aggregate
		Shares			Average			Average			Intrinsic
					Exercise			Remaining			Value
					Price Per			Contractual
					Share			Term (in years)
	Outstanding at December 31, 2012		1,936		$	29.03
	Granted		489			35.2
	Exercised		(524	)		25.46
	Forfeited		(69	)		32.05
	Outstanding at September 30, 2013		1,832		$	31.58			7.11		$	9,592
	Exercisable at September 30, 2013		866		$	28.73			5.14		$	6,995
Details of Restricted Stock Unit Activity	'
	Restricted stock unit activity for the nine months ended September 30, 2013 is presented below (in thousands, except per share data):
		Number of			Weighted-
		Shares			Average
					Grant Date
					Fair Value
	Unvested at December 31, 2012		301		$	32.98
	Granted		207			34.58
	Vested or settled		(67	)		32.91
	Forfeited		(56	)		31.02
	Unvested at September 30, 2013		385		$	34.14
Summary of Stock-Based Compensation Recorded in Expense Categories	'
	Stock-based compensation was recorded in the following expense categories (in thousands):
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
	Cost of services and fulfillment	$	1,061		$	835		$	2,708		$	2,213
	Selling and marketing		321			207			893			638
	General and administrative		478			367			987			1,070
	Total	$	1,860		$	1,409		$	4,588		$	3,921
Assumptions for Valuation of Options Granted under Equity Incentive Plans and Shares Subject to Purchase under Employee Stock Purchase Plan	'
	Options granted under the equity incentive plans and shares subject to purchase under the employee stock purchase plan were valued using the following assumptions:
		Three Months Ended						Three Months Ended
		September 30, 2013						September 30, 2012
		Equity Incentive			Employee Stock			Equity Incentive			Employee Stock
		Plans			Purchase Plan			Plans			Purchase Plan
	Average risk-free interest rate		1.4	%		0.08	%		0.62	%		0.14	%
	Expected dividend yield		2.1	%		2.1	%		1.7	%		1.7	%
	Expected life		4.9 Years			0.5 Years			4.5 Years			0.5 Years
	Expected volatility		36	%		19	%		40	%		31	%
	Weighted average fair value	$	9.94		$	6.02		$	9.42		$	6.89
		Nine Months Ended						Nine Months Ended
		September 30, 2013						September 30, 2012
		Equity Incentive			Employee Stock			Equity Incentive			Employee Stock
		Plans			Purchase Plan			Plans			Purchase Plan
	Average risk-free interest rate		0.81	%		0.08	%		0.87	%		0.14	%
	Expected dividend yield		2.1	%		2.1	%		1.7	%		1.7	%
	Expected life		4.9 Years			0.5 Years			4.5 Years			0.5 Years
	Expected volatility		37	%		19	%		40	%		31	%
	Weighted average fair value	$	9.15		$	6.02		$	9.81		$	6.87

Operating_Segments_Tables

Operating Segments (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Summary of Information about Reportable Segments	'
	The following tables present information about reportable segments (in thousands):
		BT		M&S		Events			Consolidated
	Three Months Ended September 30, 2013
	Revenue	$	37,659	$	31,809	$	347		$	69,815
	Direct margin		24,912		20,923		(656	)		45,179
	Selling, marketing, administrative and other expenses									(40,321	)
	Amortization of intangible assets									(557	)
	Reorganization costs									—
	Other income (expense) and gains (losses) on investments									(53	)
	Income before income taxes								$	4,248
		BT		M&S		Events			Consolidated
	Three Months Ended September 30, 2012
	Revenue	$	37,764	$	30,707	$	302		$	68,773
	Direct margin		25,966		20,203		(727	)		45,442
	Selling, marketing, administrative and other expenses									(37,696	)
	Amortization of intangible assets									(579	)
	Reorganization costs									(37	)
	Other income (expense) and gains (losses) on investments									1,112
	Income before income taxes								$	8,242
		BT		M&S		Events			Consolidated
	Nine Months Ended September 30, 2013
	Revenue	$	115,327	$	95,690	$	9,112		$	220,129
	Direct margin		78,100		62,909		3,204			144,213
	Selling, marketing, administrative and other expenses									(123,269	)
	Amortization of intangible assets									(1,670	)
	Reorganization costs									(1,905	)
	Other income (expense) and gains (losses) on investments									476
	Income before income taxes								$	17,845
		BT		M&S		Events			Consolidated
	Nine Months Ended September 30, 2012
	Revenue	$	115,470	$	92,995	$	9,405		$	217,870
	Direct margin		78,882		60,823		3,241			142,946
	Selling, marketing, administrative and other expenses									(116,921	)
	Amortization of intangible assets									(1,779	)
	Reorganization costs									(1,431	)
	Other income (expense) and gains (losses) on investments									1,794
	Income before income taxes								$	24,609

Interim_Consolidated_Financial2

Interim Consolidated Financial Statements - Additional Information (Detail) (USD $)

3 Months Ended

6 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

6 Months Ended

12 Months Ended

3 Months Ended

In Millions, unless otherwise specified

Jun. 30, 2013

Sep. 30, 2012

Mar. 31, 2012

Jun. 30, 2013

Dec. 31, 2011

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Dec. 31, 2012

Dec. 31, 2011

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Jun. 30, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Research Service Revenue [Member]

Research Service Revenue [Member]

Research Service Revenue [Member]

Research Service Revenue [Member]

Research Service Revenue [Member]

Technology Related Investment Funds [Member]

Technology Related Investment Funds [Member]

Technology Related Investment Funds [Member]

Technology Related Investment Funds [Member]

Technology Related Investment Funds [Member]

Technology Related Investment Funds [Member]

Adjustments Related to Insignificant Variances in Deferred Revenue [Member]

Adjustments Related to Insignificant Variances in Deferred Revenue [Member]

Adjustments Related to Insignificant Variances in Deferred Revenue [Member]

Adjustments Related to Insignificant Variances in Deferred Revenue [Member]

Adjustments Related to Insignificant Variances in Deferred Revenue [Member]

Adjustments Related to Insignificant Variances in Deferred Revenue [Member]

Adjustments Related to Insignificant Variances in Deferred Revenue [Member]

Adjustments Related to Improper Capitalization of Software Development Costs [Member]

Adjustments Related to Improper Capitalization of Software Development Costs [Member]

Adjustments Related to Improper Capitalization of Software Development Costs [Member]

Adjustments related to prior period errors

$0.80

$0.10

($0.10)

$0.80

$0.10

$0.10

($0.10)

($0.10)

$0.60

$0.50

($1.40)

($0.10)

$0.10

$0.20

($0.20)

($0.10)

$0.10

($0.40)

($0.50)

$0.30

$0.20

Interim_Consolidated_Financial3

Interim Consolidated Financial Statements - Revised Consolidated Statements of Income (Detail) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended		3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended		3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2013	Jun. 30, 2012	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2013	Jun. 30, 2012	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2013	Jun. 30, 2012	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
					As Previously Reported [Member]	As Previously Reported [Member]	As Previously Reported [Member]	As Previously Reported [Member]	As Previously Reported [Member]	As Previously Reported [Member]	As Previously Reported [Member]	As Previously Reported [Member]	As Previously Reported [Member]	As Previously Reported [Member]	As Previously Reported [Member]	Adjustments [Member]	Adjustments [Member]	Adjustments [Member]	Adjustments [Member]	Adjustments [Member]	Adjustments [Member]	Adjustments [Member]	Adjustments [Member]	Adjustments [Member]	Adjustments [Member]	Adjustments [Member]	As Revised [Member]	As Revised [Member]	As Revised [Member]	As Revised [Member]	As Revised [Member]	As Revised [Member]	As Revised [Member]	As Revised [Member]	As Revised [Member]	As Revised [Member]	As Revised [Member]
Revenues:	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'
Research services	$49,855	$50,509	$151,445	$151,145	$50,512	$50,378	$51,866	$50,300	$51,072	$49,760	$100,890	$100,832	$151,132	$202,998	$191,648	$800	($100)	$80	$209	($100)	($96)	$700	($196)	$13	$93	($153)	$51,312	$50,278	$51,946	$50,509	$50,972	$49,664	$101,590	$100,636	$151,145	$203,091	$191,495
Advisory services and other	19,960	18,264	68,684	66,725	27,652	21,121	23,200	18,211	28,021	20,500	48,773	48,521	66,732	89,932	91,968	-11	-38	15	53	-61	1	-49	-60	-7	8	-128	27,641	21,083	23,215	18,264	27,960	20,501	48,724	48,461	66,725	89,940	91,840
Total revenues	69,815	68,773	220,129	217,870	78,164	71,499	75,066	68,511	79,093	70,260	149,663	149,353	217,864	292,930	283,616	789	-138	95	262	-161	-95	651	-256	6	101	-281	78,953	71,361	75,161	68,773	78,932	70,165	150,314	149,097	217,870	293,031	283,335
Operating expenses:	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'	'
General and administrative	-9,310	-8,720	-27,217	-27,124	'	'	10,199	8,411	8,645	'	'	18,256	26,667	36,866	'	'	'	-457	309	148	'	'	148	457	'	'	'	'	9,742	8,720	8,793	'	'	18,404	27,124	36,866	'
Total operating expenses	65,514	61,643	202,760	195,055	'	'	67,673	61,334	67,632	'	'	133,264	194,598	262,271	'	'	'	-457	309	148	'	'	148	457	'	'	'	'	67,216	61,643	67,780	'	'	133,412	195,055	262,271	'
Income from operations	4,301	7,130	17,369	22,815	8,999	3,418	7,393	7,177	11,461	4,628	12,417	16,089	23,266	30,659	36,997	789	-138	552	-47	-309	-95	651	-404	-451	101	-281	9,788	3,280	7,945	7,130	11,152	4,533	13,068	15,685	22,815	30,760	36,716
Gains (losses) on investments, net	18	755	-84	898	-51	-51	-739	147	84	59	-102	143	290	-449	1,018	149	-149	-65	608	'	'	'	'	608	543	-1,417	98	-200	-804	755	84	59	-102	143	898	94	-399
Income before income taxes	4,248	8,242	17,845	24,609	9,203	3,743	7,058	7,681	11,675	5,096	12,946	16,771	24,452	31,510	38,645	938	-287	487	561	-309	-95	651	-404	157	644	-1,698	10,141	3,456	7,545	8,242	11,366	5,001	13,597	16,367	24,609	32,154	36,947
Income tax provision	1,813	-2,468	7,056	3,191	3,581	1,402	2,807	-2,692	3,906	1,915	4,983	5,821	3,129	5,936	15,635	375	-115	195	224	-124	-38	260	-162	62	257	-679	3,956	1,287	3,002	-2,468	3,782	1,877	5,243	5,659	3,191	6,193	14,956
Net income	$2,435	$10,710	$10,789	$21,418	$5,622	$2,341	$4,251	$10,373	$7,769	$3,181	$7,963	$10,950	$21,323	$25,574	$23,010	$563	($172)	$292	$337	($185)	($57)	$391	($242)	$95	$387	($1,019)	$6,185	$2,169	$4,543	$10,710	$7,584	$3,124	$8,354	$10,708	$21,418	$25,961	$21,991
Basic income per common share	$0.12	$0.48	$0.51	$0.95	$0.26	$0.10	$0.19	$0.46	$0.34	$0.14	$0.37	$0.48	$0.94	$1.14	$1.02	$0.03	'	$0.01	$0.02	'	'	$0.01	($0.01)	$0.01	$0.01	($0.05)	$0.29	$0.10	$0.20	$0.48	$0.34	$0.14	$0.38	$0.47	$0.95	$1.15	$0.97
Diluted income per common share	$0.12	$0.47	$0.50	$0.93	$0.26	$0.10	$0.19	$0.45	$0.34	$0.14	$0.36	$0.47	$0.93	$1.12	$0.99	$0.02	'	$0.01	$0.02	($0.01)	($0.01)	$0.02	($0.01)	'	$0.01	($0.04)	$0.28	$0.10	$0.20	$0.47	$0.33	$0.13	$0.38	$0.46	$0.93	$1.13	$0.95

Interim_Consolidated_Financial4

Interim Consolidated Financial Statements - Revised Consolidated Balance Sheet (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Current Assets:	'	'
Prepaid expenses and other current assets	$18,645	$18,978
Total current assets	221,723	336,697
Other assets	11,166	8,809
Total assets	368,828	487,650
Current Liabilities:	'	'
Deferred revenue	125,787	150,495
Total current liabilities	151,889	181,345
Total liabilities	160,861	190,778
Retained earnings	118,814	117,450
Total stockholders' equity	207,967	296,872
Total liabilities and stockholders' equity	368,828	487,650
As Previously Reported [Member]	'	'
Current Assets:	'	'
Prepaid expenses and other current assets	'	18,846
Total current assets	'	336,565
Other assets	'	9,123
Total assets	'	487,832
Current Liabilities:	'	'
Deferred revenue	'	150,479
Total current liabilities	'	181,329
Total liabilities	'	190,762
Retained earnings	'	117,648
Total stockholders' equity	'	297,070
Total liabilities and stockholders' equity	'	487,832
Adjustments [Member]	'	'
Current Assets:	'	'
Prepaid expenses and other current assets	'	132
Total current assets	'	132
Other assets	'	-314
Total assets	'	-182
Current Liabilities:	'	'
Deferred revenue	'	16
Total current liabilities	'	16
Total liabilities	'	16
Retained earnings	'	-198
Total stockholders' equity	'	-198
Total liabilities and stockholders' equity	'	-182
As Revised [Member]	'	'
Current Assets:	'	'
Prepaid expenses and other current assets	'	18,978
Total current assets	'	336,697
Other assets	'	8,809
Total assets	'	487,650
Current Liabilities:	'	'
Deferred revenue	'	150,495
Total current liabilities	'	181,345
Total liabilities	'	190,778
Retained earnings	'	117,450
Total stockholders' equity	'	296,872
Total liabilities and stockholders' equity	'	$487,650

Interim_Consolidated_Financial5

Interim Consolidated Financial Statements - Revised Consolidated Statements of Cash Flows (Detail) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

6 Months Ended

9 Months Ended

12 Months Ended

3 Months Ended

6 Months Ended

9 Months Ended

12 Months Ended

3 Months Ended

6 Months Ended

9 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Jun. 30, 2013

Jun. 30, 2012

Sep. 30, 2012

Dec. 31, 2012

Dec. 31, 2011

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Jun. 30, 2013

Jun. 30, 2012

Sep. 30, 2012

Dec. 31, 2012

Dec. 31, 2011

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Jun. 30, 2013

Jun. 30, 2012

Sep. 30, 2012

Dec. 31, 2012

Dec. 31, 2011

As Previously Reported [Member]

As Previously Reported [Member]

As Previously Reported [Member]

As Previously Reported [Member]

As Previously Reported [Member]

As Previously Reported [Member]

As Previously Reported [Member]

As Previously Reported [Member]

As Previously Reported [Member]

As Previously Reported [Member]

As Previously Reported [Member]

Adjustments [Member]

Adjustments [Member]

Adjustments [Member]

Adjustments [Member]

Adjustments [Member]

Adjustments [Member]

Adjustments [Member]

Adjustments [Member]

Adjustments [Member]

Adjustments [Member]

Adjustments [Member]

As Revised [Member]

As Revised [Member]

As Revised [Member]

As Revised [Member]

As Revised [Member]

As Revised [Member]

As Revised [Member]

As Revised [Member]

As Revised [Member]

As Revised [Member]

As Revised [Member]

Cash flows from operating activities:

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income

$2,435

$10,710

$10,789

$21,418

$5,622

$2,341

$4,251

$10,373

$7,769

$3,181

$7,963

$10,950

$21,323

$25,574

$23,010

$563

($172)

$292

$337

($185)

($57)

$391

($242)

$95

$387

($1,019)

$6,185

$2,169

$4,543

$10,710

$7,584

$3,124

$8,354

$10,708

$21,418

$25,961

$21,991

Net (gains) losses from investments

-18

-755

84

-898

51

51

739

-147

-84

-59

102

-143

-290

449

-1,018

-149

149

65

-608

'

'

'

'

-608

-543

1,417

-98

200

804

-755

-84

-59

102

-143

-898

-94

399

Prepaid expenses and other current assets

'

'

3,683

3,991

'

1,271

'

'

'

'

4,619

'

3,929

6,279

-7,805

'

-115

'

'

'

'

260

'

62

257

-679

'

1,156

'

'

'

'

4,879

'

3,991

6,536

-8,484

Deferred revenue

'

'

-25,002

-23,308

'

2,709

'

'

'

'

-12,955

'

-23,302

1,807

16,364

'

138

'

'

'

'

-651

'

-6

-101

281

'

2,847

'

'

'

'

-13,606

'

-23,308

1,706

16,645

Net cash provided by operating activities

'

'

32,352

42,766

'

35,453

'

'

'

'

37,231

'

43,223

53,147

55,444

'

'

'

'

'

'

'

'

-457

'

'

'

35,453

'

'

'

'

37,231

'

42,766

53,147

55,444

Purchases of property and equipment

'

'

2,049

4,388

'

'

'

'

'

'

'

'

-4,845

-5,103

-39,776

'

'

'

'

'

'

'

'

457

'

'

'

'

'

'

'

'

'

'

-4,388

-5,103

-39,776

Net cash provided by (used in) investing activities

'

'

$43,847

($15,532)

'

'

'

'

'

'

'

'

($15,989)

($4,076)

($53,036)

'

'

'

'

'

'

'

'

$457

'

'

'

'

'

'

'

'

'

'

($15,532)

($4,076)

($53,036)

Marketable_Investments_Summary

Marketable Investments - Summary of Company's Marketable Investments (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	$97,990	$145,512
Gross Unrealized Gains	136	407
Gross Unrealized Losses	-2,073	-2,073
Total short and long term	96,053	143,846
State and Municipal Obligations [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	9,660	18,859
Gross Unrealized Gains	5	27
Gross Unrealized Losses	'	-14
Total short and long term	9,665	18,872
Federal Agency and Corporate Obligations [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	77,330	115,653
Gross Unrealized Gains	131	380
Gross Unrealized Losses	-165	-29
Total short and long term	77,296	116,004
Total Short-Term Available-for-Sale Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	86,990	134,512
Gross Unrealized Gains	136	407
Gross Unrealized Losses	-165	-43
Total short and long term	86,961	134,876
ARS [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost	11,000	11,000
Gross Unrealized Gains	'	'
Gross Unrealized Losses	-1,908	-2,030
Total short and long term	$9,092	$8,970

Marketable_Investments_Summary1

Marketable Investments - Summary of Maturity Periods of the Marketable Securities (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
FY 2013, Total	$10,157	'
FY 2014, Total	29,856	'
FY 2015, Total	30,991	'
Thereafter, Total	25,049	'
Total short and long term	96,053	143,846
State and Municipal Obligations [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
FY 2013, Total	2,772	'
FY 2014, Total	4,821	'
FY 2015, Total	2,072	'
Thereafter, Total	'	'
Total short and long term	9,665	18,872
Federal Agency and Corporate Obligations [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
FY 2013, Total	7,385	'
FY 2014, Total	25,035	'
FY 2015, Total	28,919	'
Thereafter, Total	15,957	'
Total short and long term	77,296	116,004
ARS [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
FY 2013, Total	'	'
FY 2014, Total	'	'
FY 2015, Total	'	'
Thereafter, Total	9,092	'
Total short and long term	$9,092	$8,970

Marketable_Investments_Summary2

Marketable Investments - Summary of Gross Unrealized Losses and Market Value of Available-for-Sale Securities with Unrealized Losses (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Available for sale securities, Less Than 12 Months, Market Value	$35,843	$27,146
Available for sale securities, Less Than 12 Months, Unrealized Losses	165	43
Available for sale securities, 12 Months or Greater, Market Value	9,092	8,970
Available for sale securities, 12 Months or Greater, Unrealized Losses	1,908	2,030
State and Municipal Obligations [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available for sale securities, Less Than 12 Months, Market Value	'	9,430
Available for sale securities, Less Than 12 Months, Unrealized Losses	'	14
Available for sale securities, 12 Months or Greater, Market Value	'	'
Available for sale securities, 12 Months or Greater, Unrealized Losses	'	'
Federal Agency and Corporate Obligations [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available for sale securities, Less Than 12 Months, Market Value	35,843	17,716
Available for sale securities, Less Than 12 Months, Unrealized Losses	165	29
Available for sale securities, 12 Months or Greater, Market Value	'	'
Available for sale securities, 12 Months or Greater, Unrealized Losses	'	'
ARS [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Available for sale securities, Less Than 12 Months, Market Value	'	'
Available for sale securities, Less Than 12 Months, Unrealized Losses	'	'
Available for sale securities, 12 Months or Greater, Market Value	9,092	8,970
Available for sale securities, 12 Months or Greater, Unrealized Losses	$1,908	$2,030

Marketable_Investments_Summary3

Marketable Investments - Summary of Company's Fair Value Hierarchy for its Financial Assets (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	$103,164	$176,774
Money Market Funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	7,111	815
State and Municipal Obligations [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	9,665	18,872
Federal Agency and Corporate Obligations [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	77,296	148,117
ARS [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	9,092	8,970
Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	7,111	815
Level 1 [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	7,111	815
Level 1 [Member] | State and Municipal Obligations [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	'	'
Level 1 [Member] | Federal Agency and Corporate Obligations [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	'	'
Level 1 [Member] | ARS [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	'	'
Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	86,961	166,989
Level 2 [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	'	'
Level 2 [Member] | State and Municipal Obligations [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	9,665	18,872
Level 2 [Member] | Federal Agency and Corporate Obligations [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	77,296	148,117
Level 2 [Member] | ARS [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	'	'
Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	9,092	8,970
Level 3 [Member] | Money Market Funds [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	'	'
Level 3 [Member] | State and Municipal Obligations [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	'	'
Level 3 [Member] | Federal Agency and Corporate Obligations [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	'	'
Level 3 [Member] | ARS [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of assets on recurring basis	$9,092	$8,970

Marketable_Investments_Summary4

Marketable Investments - Summary of Company's Fair Value Hierarchy for its Financial Assets (Parenthetical) (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
		Federal Agency and Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Cash and cash equivalents	'	$32.10
Original maturities	'90 days	'

Marketable_Investments_Additio

Marketable Investments - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Oct. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified	Accumulated Net Unrealized Investment Gain (Loss) [Member]	Accumulated Net Unrealized Investment Gain (Loss) [Member]	ARS [Member]	ARS [Member]	Minimum [Member]	Minimum [Member]	Maximum [Member]	Maximum [Member]
			Subsequent Event [Member]	Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'	'	'	'	'	'
Intervals for each security	'	'	'	'	'7 days	'	'35 days	'
Interest rates on securities ranged	'	'	'	'	0.10%	0.10%	0.40%	0.50%
Weighted average interest rate	'	'	'	1.70%	'	'	'	'
Weighted average discount rate	'	'	'	4.90%	'	'	'	'
Weighted average holding period	'	'	'	'8 years 8 months 12 days	'	'	'	'
Unrealized loss recorded in accumulated other comprehensive income	$1.90	$2	'	'	'	'	'	'
Proceeds from sale of ARS	'	'	9.1	'	'	'	'	'
Loss realized on ARS	'	'	$1.90	'	'	'	'	'

Marketable_Investments_Summary5

Marketable Investments - Summary of Changes in Fair Value of Level 3 Financial Assets (Detail) (ARS [Member], Level 3 [Member], USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
ARS [Member] | Level 3 [Member]	'	'
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]	'	'
Fair value of assets, Beginning Balance	$8,970	$9,565
Sales	'	'
Gains included in other comprehensive income	122	224
Fair value of assets, Ending Balance	$9,092	$9,789

NonMarketable_Investments_Addi

Non-Marketable Investments - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended				3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013
				Technology Related Private Equity Funds [Member]	Technology Related Private Equity Funds [Member]	Non-marketable Investments [Member]	Non-marketable Investments [Member]	Non-marketable Investments [Member]	Maximum [Member]	Minimum [Member]
									Participant
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]	'	'	'	'	'	'	'	'	'	'
Carrying value of the Company's non-marketable investments	'	'	'	$6,200,000	$6,600,000	'	'	'	'	'
Ownership interest of company	'	'	'	'	'	'	'	'	'	5.00%
Gain (losses) from non-marketable investments	0	'	'	'	'	800,000	-100,000	900,000	'	'
Book value of investment	900,000	900,000	1,200,000	'	'	'	'	'	'	'
Bonus paid under cash bonus plan	'	$0	'	'	'	'	'	'	'	'
Cash bonus plan expiration date	'	30-Jun-15	'	'	'	'	'	'	'	'
Participant in the cash bonus plan	'	'	'	'	'	'	'	'	10	'

Reorganization_Summary_of_Roll

Reorganization - Summary of Roll Forward of Activity in Reorganization Accrual (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Additions	'	$37	$1,905	$1,431
Workforce Reduction [Member]	'	'	'	'
Restructuring Cost and Reserve [Line Items]	'	'	'	'
Accrual Beginning Balance	'	'	14	'
Additions	'	'	1,905	'
Cash payments	'	'	-1,655	'
Accrual Ending Balance	$264	'	$264	'

Reorganization_Additional_Info

Reorganization - Additional Information (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
	Job
Restructuring And Related Activities [Abstract]	'
Severance and related costs	$1.90
Number of jobs eliminated worldwide	31
Number of jobs eliminated worldwide, percentage	2.50%

Net_Income_Per_Common_Share_Su

Net Income Per Common Share - Summary of Basic and Diluted Weighted Average Common Shares (Detail)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]	'	'	'	'
Basic weighted average common shares outstanding	20,117	22,398	21,226	22,573
Weighted average common equivalent shares	548	460	464	445
Diluted weighted average common shares outstanding	20,665	22,858	21,690	23,018
Options excluded from diluted weighted average share calculation as effect would have been anti-dilutive	608	967	700	644

Stockholders_Equity_Summary_of

Stockholders' Equity - Summary of Stock Option Activity (Detail) (USD $)	9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Number of Shares, Outstanding at December 31, 2012	1,936
Number of Shares, Granted	489
Number of Shares, Exercised	-524
Number of Shares, Forfeited	-69
Number of Shares, Outstanding at September 30 2013	1,832
Number of Shares, Exercisable at September 30 2013	866
Weighted Average Exercise Price Per Share, Outstanding, Beginning balance	$29.03
Weighted Average Exercise Price Per Share, Granted	$35.20
Weighted Average Exercise Price Per Share, Exercised	$25.46
Weighted Average Exercise Price Per Share, Forfeited	$32.05
Weighted Average Exercise Price Per Share, Outstanding, Ending balance	$31.58
Weighted Average Exercise Price Per Share, Exercisable at September 30, 2013	$28.73
Weighted Average Remaining Contractual Term, Outstanding at September 30, 2013	'7 years 1 month 10 days
Weighted Average Remaining Contractual Term, Exercisable at September 30, 2013	'5 years 1 month 21 days
Aggregate Intrinsic Value, Outstanding at September 30, 2013	$9,592
Aggregate Intrinsic Value, Exercisable at September 30, 2013	$6,995

Stockholders_Equity_Details_of

Stockholders' Equity - Details of Restricted Stock Unit Activity (Detail) (USD $)	9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Number of Shares, Unvested at December 31, 2012	301
Number of Shares, Granted	207
Number of Shares, Vested or settled	-67
Number of Shares, Forfeited	-56
Number of Shares, Unvested at September 30, 2013	385
Weighted Average Grant Date Fair Value, Unvested, Beginning Balance	$32.98
Weighted Average Grant Date Fair Value, Granted	$34.58
Weighted Average Grant Date Fair Value, Vested or settled	$32.91
Weighted Average Grant Date Fair Value, Forfeited	$31.02
Weighted Average Grant Date Fair Value , Unvested, Ending Balance	$34.14

Stockholders_Equity_Summary_of1

Stockholders' Equity - Summary of Stock-Based Compensation Recorded in Expense Categories (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Total allocated share-based compensation expense	$1,860	$1,409	$4,588	$3,921
Cost of Services and Fulfillment [Member]	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Total allocated share-based compensation expense	1,061	835	2,708	2,213
Selling and Marketing [Member]	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Total allocated share-based compensation expense	321	207	893	638
General and Administrative [Member]	'	'	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'	'	'
Total allocated share-based compensation expense	$478	$367	$987	$1,070

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)

1 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

12 Months Ended

In Millions, except Share data, unless otherwise specified

Jul. 31, 2013

Apr. 30, 2013

Feb. 28, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Apr. 30, 2013

Apr. 30, 2013

Oct. 31, 2013

Sep. 30, 2013

Dec. 31, 2011

Dec. 31, 2010

Minimum [Member]

Maximum [Member]

Subsequent Event [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Restricted Stock Units (RSUs) [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

RSU's issued

'

'

'

385,000

'

'

'

'

'

385,000

'

301,000

'

'

'

'

71,000

63,000

Performance of RSU's Vesting

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'100% or 40% on April 1, 2014

'100% or 40% on April 1, 2013

Compensation expense Estimate vesting

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

100.00%

Modified Estimate vesting of RSU's

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.00%

'

0.00%

Dividend declared and paid per share

'

'

'

$0.15

$0.15

$0.15

$0.14

$0.14

$0.14

'

'

'

'

'

'

'

'

'

Aggregate dividend declared for the year

'

'

'

'

'

'

'

'

'

$9.40

$9.50

'

'

'

'

'

'

'

Dividend declared

'

'

'

$0.15

'

'

$0.14

'

'

$0.45

$0.42

'

'

'

$0.15

'

'

'

Aggregate cost of repurchase of common stock

'

'

'

'

'

'

'

'

'

320

'

'

'

'

'

'

'

'

Authorized to Purchase of common stock under the stock repurchase program

25

'

50

'

'

'

'

'

'

385

'

'

'

'

'

'

'

'

Cumulative repurchase of common stock

'

'

'

12,200,000

'

'

'

'

'

12,200,000

'

'

'

'

'

'

'

'

Repurchase of common Stock

'

'

'

'

'

'

'

'

'

3,000,000

'

'

'

'

'

'

'

'

Cumulative aggregate cost of repurchase of common stock

'

'

'

'

'

'

'

'

'

109.2

'

'

'

'

'

'

'

'

Repurchase of self-tender

'

130

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common stock price per share

'

'

'

'

'

'

'

'

'

'

'

'

$32

$36

'

'

'

'

Increment in per share value

'

$0.25

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase of common stock

'

2,054,732

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase price of common stock

'

$36

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate price of stock

'

74

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expenses related to tender offer

'

1.1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Treasury stock, retired

'

'

'

'

'

'

'

'

'

11,700,000

'

'

'

'

'

'

'

'

Carrying value of retired stock

'

'

'

'

'

'

'

'

'

$303

'

'

'

'

'

'

'

'

Stockholders_Equity_Assumption

Stockholders' Equity - Assumptions for Valuation of Options Granted under Equity Incentive Plans and Shares Subject to Purchase under Employee Stock Purchase Plan (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Equity Incentive Plans [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Average risk-free interest rate	1.40%	0.62%	0.81%	0.87%
Expected dividend yield	2.10%	1.70%	2.10%	1.70%
Expected life	'4 years 10 months 24 days	'4 years 6 months 0 days	'4 years 10 months 24 days	'4 years 6 months 0 days
Expected volatility	36.00%	40.00%	37.00%	40.00%
Weighted average fair value	$9.94	$9.42	$9.15	$9.81
Employee Stock Purchase Plan [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Average risk-free interest rate	0.08%	0.14%	0.08%	0.14%
Expected dividend yield	2.10%	1.70%	2.10%	1.70%
Expected life	'6 months 0 days	'6 months 0 days	'6 months 0 days	'6 months 0 days
Expected volatility	19.00%	31.00%	19.00%	31.00%
Weighted average fair value	$6.02	$6.89	$6.02	$6.87

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]	'	'	'	'
Income tax expense	$1,813,000	($2,468,000)	$7,056,000	$3,191,000
Effective tax rate	'	'	39.50%	13.00%
Increase in the effective tax	'	'	$5,500,000	'

Operating_Segments_Additional_

Operating Segments - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2013
	Segment
Segment Reporting [Abstract]	'
Number of Operating Segments	2

Operating_Segments_Summary_of_

Operating Segments - Summary of Information about Reportable Segments (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	$69,815	$68,773	$220,129	$217,870
Direct margin	45,179	45,442	144,213	142,946
Selling, marketing, administrative and other expenses	-40,321	-37,696	-123,269	-116,921
Amortization of intangible assets	-557	-579	-1,670	-1,779
Reorganization costs	'	-37	-1,905	-1,431
Other income (expense) and gains (losses) on investments	-53	1,112	476	1,794
Income before income taxes	4,248	8,242	17,845	24,609
BT [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	37,659	37,764	115,327	115,470
Direct margin	24,912	25,966	78,100	78,882
Selling, marketing, administrative and other expenses	'	'	'	'
Amortization of intangible assets	'	'	'	'
Reorganization costs	'	'	'	'
Other income (expense) and gains (losses) on investments	'	'	'	'
Income before income taxes	'	'	'	'
M&S [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	31,809	30,707	95,690	92,995
Direct margin	20,923	20,203	62,909	60,823
Selling, marketing, administrative and other expenses	'	'	'	'
Amortization of intangible assets	'	'	'	'
Reorganization costs	'	'	'	'
Other income (expense) and gains (losses) on investments	'	'	'	'
Income before income taxes	'	'	'	'
Events [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Revenue	347	302	9,112	9,405
Direct margin	-656	-727	3,204	3,241
Selling, marketing, administrative and other expenses	'	'	'	'
Amortization of intangible assets	'	'	'	'
Reorganization costs	'	'	'	'
Other income (expense) and gains (losses) on investments	'	'	'	'
Income before income taxes	'	'	'	'

Recent_Accounting_Pronouncemen2

Recent Accounting Pronouncements - Additional Information (Detail) (USD $)	Sep. 30, 2013
Goodwill And Intangible Assets Disclosure [Abstract]	'
Indefinite-lived intangible assets	$0