Heidrick & Struggles International (HSII) 10-Q 28 Oct 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 25, 2019
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	HSII
Entity Registrant Name	HEIDRICK & STRUGGLES INTERNATIONAL INC
Entity Central Index Key	0001066605
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		19,170,352

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 176,372,000	$ 279,906,000
Marketable Securities	42,566,000	0
Accounts receivable, net	150,872,000	114,977,000
Prepaid expenses	20,436,000	22,766,000
Other current assets	27,966,000	29,598,000
Income taxes recoverable	5,818,000	3,620,000
Total current assets	424,030,000	450,867,000
Non-current assets
Property and equipment, net	29,356,000	33,871,000
Operating Lease, Right-of-Use Asset	98,097,000	0
Assets designated for retirement and pension plans	14,289,000	15,035,000
Investments	23,807,000	19,442,000
Other non-current assets	20,317,000	22,276,000
Goodwill	128,286,000	122,092,000
Other intangible assets, net	(4,428,000)	(2,216,000)
Deferred income taxes	34,013,000	34,830,000
Total non-current assets	352,593,000	249,762,000
Total assets	776,623,000	700,629,000
Current liabilities
Accounts payable	9,093,000	9,166,000
Accrued salaries and employee benefits	180,207,000	227,653,000
Deferred revenue	40,434,000	40,673,000
Operating Lease, Liability, Current	30,663,000	0
Other current liabilities	29,327,000	33,219,000
Income taxes payable	6,517,000	8,240,000
Total current liabilities	296,241,000	318,951,000
Long-term Line of Credit	0	0
Employee-related Liabilities, Non-current	53,099,000	57,234,000
Non-current liabilities
Retirement and pension plans	43,269,000	39,865,000
Operating Lease, Liability, Noncurrent	76,871,000	0
Other non-current liabilities	10,508,000	17,423,000
Total non-current liabilities	183,747,000	114,522,000
Total liabilities	479,988,000	433,473,000
Commitments and contingencies (Note 18)
Stockholders’ equity
Preferred stock, $0.01 par value, 10,000,000 shares authorized, no shares issued at March 31, 2019 and December 31, 2018	0	0
Common stock, $0.01 par value, 100,000,000 shares authorized, 19,585,777 shares issued, 19,113,630 and 18,954,275 shares outstanding at March 31, 2019 and December 31, 2018, respectively	196,000	196,000
Treasury stock at cost, 472,147 and 631,502 shares at March 31, 2019 and December 31, 2018, respectively	(14,795,000)	(20,298,000)
Additional paid in capital	224,687,000	227,147,000
Retained earnings	83,497,000	56,049,000
Accumulated other comprehensive income	3,050,000	4,062,000
Total stockholders’ equity	296,635,000	267,156,000
Total liabilities and stockholders’ equity	$ 776,623,000	$ 700,629,000

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value (in USD per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	19,585,777	19,585,777
Common stock, shares outstanding	19,127,401	18,954,275
Treasury stock, shares	458,376	631,502

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue, Net of Reimbursements	$ 182,174	$ 187,588	$ 526,890	$ 530,718
Revenue
Reimbursements Revenue	4,344	4,753	14,075	13,970
Total revenue	186,518	192,341	540,965	544,688
Operating expenses
Salaries and employee benefits	130,479	133,933	371,898	373,021
General and administrative expenses	33,093	33,072	101,646	105,532
Goodwill and Intangible Asset Impairment	4,130	0	4,130	0
Reimbursable Expenses	4,344	4,753	14,075	13,970
Total operating expenses	172,046	171,758	491,749	492,523
Operating income	14,472	20,583	49,216	52,165
Non-operating income (expense)
Interest, net	819	259	2,039	496
Other, net	(464)	2,345	1,887	1,849
Net non-operating income (expense)	355	2,604	3,926	2,345
Income before income taxes	14,827	23,187	53,142	54,510
Provision for income taxes	(4,880)	(6,718)	(16,828)	(16,410)
Net income	9,947	16,469	36,314	38,100
Other comprehensive income, net of tax
Foreign currency translation adjustment	(1,337)	(881)	(1,024)	(3,107)
Net unrealized gain on available-for-sale investments	0	0	12	0
Other comprehensive income, net of tax	(1,337)	(881)	(1,012)	(3,107)
Comprehensive income	$ 8,610	$ 15,588	$ 35,302	$ 34,993
Basic weighted average common shares outstanding (in shares)	19,127	18,954	19,084	18,905
Diluted weighted average common shares outstanding (in shares)	19,428	19,401	19,518	19,444
Basic net income per common share (in USD per share)	$ 0.52	$ 0.87	$ 1.90	$ 2.02
Diluted net income per common share (in USD per share)	0.51	0.85	1.86	1.96
Cash dividends paid per share (in USD per share)	$ 0.15	$ 0.13	$ 0.45	$ 0.39

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Beginning balance at Dec. 31, 2017	$ 212,705	$ 196	$ (26,096)	$ 226,006	$ (716)	$ 13,315
Beginning balance, shares at Dec. 31, 2017		19,586,000	805,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	10,168				10,168
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	8,954
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | Accounting Standards Update 2014-09 [Member]					15,043
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | Accounting Standards Update 2016-01 [Member]						(6,089)
Other comprehensive income, net of tax	1,590					1,590
Common and treasury stock transactions:
Stock-based compensation	1,776			1,776
Vesting of equity, net of tax withholdings	(2,233)		$ (4,614)	(6,847)
Dividends, Cash	(2,460)				(2,460)
Vesting of equity, net of tax withholdings, shares			138,000
Dividend equivalents on restricted stock units	11				11
Ending balance at Mar. 31, 2018	230,489	$ 196	$ (21,482)	220,935	22,024	8,816
Ending balance, shares at Mar. 31, 2018		19,586,000	667,000
Beginning balance at Dec. 31, 2017	212,705	$ 196	$ (26,096)	226,006	(716)	13,315
Beginning balance, shares at Dec. 31, 2017		19,586,000	805,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	38,100
Other comprehensive income, net of tax	(3,107)
Ending balance at Sep. 30, 2018	253,833	$ 196	$ (20,298)	224,962	44,854	4,119
Ending balance, shares at Sep. 30, 2018		19,586,000	632,000
Beginning balance at Mar. 31, 2018	230,489	$ 196	$ (21,482)	220,935	22,024	8,816
Beginning balance, shares at Mar. 31, 2018		19,586,000	667,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	11,463				11,463
Other comprehensive income, net of tax	(3,816)					(3,816)
Common and treasury stock transactions:
Stock-based compensation	2,076			2,076
Vesting of equity, net of tax withholdings	0		$ (989)	(989)
Dividends, Cash	(2,465)				(2,465)
Vesting of equity, net of tax withholdings, shares			29,000
Re-issuance of treasury stock	(224)		$ (195)	(29)
Re-issuance of treasury stock, shares			(6,000)
Dividend equivalents on restricted stock units	106				106
Ending balance at Jun. 30, 2018	237,865	$ 196	$ (20,298)	222,051	30,916	5,000
Ending balance, shares at Jun. 30, 2018		19,586,000	632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	16,469				16,469
Other comprehensive income, net of tax	(881)					(881)
Common and treasury stock transactions:
Stock-based compensation	2,911			2,911
Dividends, Cash	(2,464)				2,464
Dividend equivalents on restricted stock units	67				67
Ending balance at Sep. 30, 2018	253,833	$ 196	$ (20,298)	224,962	44,854	4,119
Ending balance, shares at Sep. 30, 2018		19,586,000	632,000
Beginning balance at Dec. 31, 2018	$ 267,156	$ 196	$ (20,298)	227,147	56,049	4,062
Beginning balance, shares at Dec. 31, 2018	18,954,275	19,586,000	632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 12,087				12,087
Other comprehensive income, net of tax	320					320
Common and treasury stock transactions:
Stock-based compensation	1,343			1,343
Vesting of equity, net of tax withholdings	4,552		$ (5,155)	9,707
Dividends, Cash	(2,848)				(2,848)
Vesting of equity, net of tax withholdings, shares			160,000
Dividend equivalents on restricted stock units	87				87
Ending balance at Mar. 31, 2019	273,419	$ 196	$ (15,143)	218,783	65,201	4,382
Ending balance, shares at Mar. 31, 2019		19,586,000	472,000
Beginning balance at Dec. 31, 2018	$ 267,156	$ 196	$ (20,298)	227,147	56,049	4,062
Beginning balance, shares at Dec. 31, 2018	18,954,275	19,586,000	632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 36,314
Other comprehensive income, net of tax	(1,012)					(1,012)
Ending balance at Sep. 30, 2019	$ 296,635	$ 196	$ (14,795)	224,687	83,497	3,050
Ending balance, shares at Sep. 30, 2019	19,127,401	19,586,000	458,000
Beginning balance at Mar. 31, 2019	$ 273,419	$ 196	$ (15,143)	218,783	65,201	4,382
Beginning balance, shares at Mar. 31, 2019		19,586,000	472,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	14,280				14,280
Other comprehensive income, net of tax	5					5
Common and treasury stock transactions:
Stock-based compensation	3,368			3,368
Vesting of equity, net of tax withholdings	0		$ 0	0
Dividends, Cash	(2,867)				(2,867)
Vesting of equity, net of tax withholdings, shares			3,000
Re-issuance of treasury stock	(345)		$ (348)	3
Re-issuance of treasury stock, shares			11,000
Dividend equivalents on restricted stock units	101				101
Ending balance at Jun. 30, 2019	288,449	$ 196	$ (14,795)	222,148	76,513	4,387
Ending balance, shares at Jun. 30, 2019		19,586,000	458,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9,947				9,947
Other comprehensive income, net of tax	(1,337)					(1,337)
Common and treasury stock transactions:
Stock-based compensation	2,539			2,539
Dividends, Cash	(2,870)				2,870
Dividend equivalents on restricted stock units	93				93
Ending balance at Sep. 30, 2019	$ 296,635	$ 196	$ (14,795)	$ 224,687	$ 83,497	$ 3,050
Ending balance, shares at Sep. 30, 2019	19,127,401	19,586,000	458,000

Condensed Consolidated Statem_3

Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Cash dividends per share	$ 0.15	$ 0.15	$ 0.15	$ 0.13	$ 0.13	$ 0.13

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Condensed Cash Flow Statements, Captions [Line Items]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 176,372,000	$ 164,814,000
Cash flows - operating activities
Net income	36,314,000	38,100,000
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	7,983,000	9,558,000
Deferred income taxes	(24,000)	(438,000)
Stock-based compensation expense	7,250,000	6,763,000
Accretion expense related to earnout payments	(495,000)	(963,000)
Marketable Securities, Gain (Loss)	(353,000)	0
Goodwill and Intangible Asset Impairment	4,130,000	0
Changes in assets and liabilities, net of effects of acquisitions:
Accounts receivable	36,961,000	60,057,000
Accounts payable	(144,000)	(761,000)
Accrued expenses	(52,680,000)	3,834,000
Restructuring Reserve, Accrual Adjustment	2,762,000	(10,833,000)
Deferred revenue	113,000	185,000
Income taxes payable, net	(3,952,000)	(2,003,000)
Retirement and pension plan assets and liabilities	1,824,000	(1,019,000)
Prepaid expenses	920,000	3,416,000
Other assets and liabilities, net	(2,874,000)	3,761,000
Net cash used in operating activities	(35,419,000)	22,885,000
Cash flows - investing activities
Payments to Acquire Businesses, Gross	(3,520,000)	(3,119,000)
Capital expenditures	(2,641,000)	(4,939,000)
Purchases of available-for-sale investments	(83,146,000)	(2,046,000)
Proceeds from sales of available-for-sale investments	39,162,000	2,890,000
Net cash used in investing activities	(50,145,000)	(7,214,000)
Proceeds from Lines of Credit	0	20,000,000
Repayments of Lines of Credit	0	(20,000,000)
Cash flows - financing activities
Cash dividends paid	(8,866,000)	(7,573,000)
Payment of employee tax withholdings on equity transactions	(4,552,000)	(2,234,000)
Payment for Contingent Consideration Liability, Financing Activities	(1,853,000)	0
Net Cash Provided by (Used in) Financing Activities	(15,271,000)	(9,807,000)
Effect of exchange rate fluctuations on cash, cash equivalents and restricted cash	(3,055,000)	(3,442,000)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(103,890,000)	(43,348,000)
Cash, cash equivalents and restricted cash at end of period	$ 176,372,000	$ 164,216,000

Basis of Presentation of Interi

Basis of Presentation of Interim Financial Information	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation of Interim Financial Information	The accompanying unaudited Condensed Consolidated Financial Statements of Heidrick & Struggles International, Inc. and subsidiaries (the “Company”) have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses. Significant items subject to estimates and assumptions include revenue recognition, income taxes, interim effective tax rate and the assessment of goodwill and other intangible assets for impairment. Estimates are subject to a degree of uncertainty and actual results could differ from these estimates. These financial statements and notes are to be read in conjunction with the Company’s Consolidated Financial Statements and Notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 , as filed with the SEC on February 26, 2019 .

Summary of Significant Accounti

Summary of Significant Accounting Policies (Notes)	9 Months Ended
	Sep. 30, 2019
Summary of Significant Accounting Policies [Abstract]
Significant Accounting Policies [Text Block]	A complete listing of the Company’s significant accounting policies is discussed in Note 2 , Summary of Significant Accounting Policies , in the Notes to Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 . Revenue Recognition See Note 3 , Revenue . Marketable Securities The Company’s marketable securities consist of available-for-sale debt securities with original maturities exceeding three months. Available-for-sale debt securities are reported at fair value with realized gains (losses) recorded as non-operating income (expense) in Interest, net in the Condensed Consolidated Statements of Comprehensive Income. Unrealized gains (losses) are recorded as a separate component of Accumulated other comprehensive income in the Consolidated Balance Sheets until realized. Restricted Cash Historically, the Company had lease agreements and business licenses with terms that required the Company to restrict cash through the termination dates of the agreements. Current and non-current restricted cash is included in Other current assets and Other non-current assets , respectively, in the Condensed Consolidated Balance Sheets. The following table provides a reconciliation of the cash and cash equivalents between the Condensed Consolidated Balance Sheets and the Condensed Consolidated Statement of Cash Flows as of September 30, 2019 and 2018 , and December 31, 2018 and 2017 : September 30, December 31, 2019 2018 2018 2017 Cash and cash equivalents $ 176,372 $ 164,216 $ 279,906 $ 207,534 Restricted cash included within other current assets — 598 108 526 Restricted cash included within other non-current assets — — 248 102 Total cash, cash equivalents and restricted cash $ 176,372 $ 164,814 $ 280,262 $ 208,162 Earnings per Common Share Basic earnings per common share is computed by dividing net income by weighted average common shares outstanding for the period. Diluted earnings per share reflect the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted. Common equivalent shares are excluded from the determination of diluted earnings per share in periods in which they have an anti-dilutive effect. The following table sets forth the computation of basic and diluted earnings per share: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Net income $ 9,947 $ 16,469 $ 36,314 $ 38,100 Weighted average shares outstanding: Basic 19,127 18,954 19,084 18,905 Effect of dilutive securities: Restricted stock units 195 278 283 345 Performance stock units 106 169 151 194 Diluted 19,428 19,401 19,518 19,444 Basic earnings per share $ 0.52 $ 0.87 $ 1.90 $ 2.02 Diluted earnings per share $ 0.51 $ 0.85 $ 1.86 $ 1.96 Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in Operating Lease Right-of-Use Assets , Operating Lease Liabilities - Current and Operating Lease Liabilities - Non-Current in our Condensed Consolidated Balance Sheets. The Company does not have any leases that meet the finance lease criteria. Right-of-use assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized on the commencement date based on the present value of lease payments over the lease term. As most of the Company's leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The operating lease right-of-use asset also includes any lease payments made in advance and any accrued rent expense balances. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. We have lease agreements with lease and non-lease components. For office leases, we account for the lease and non-lease components as a single lease component. For equipment leases, such as vehicles and office equipment, we account for the lease and non-lease components separately. Recently Adopted Financial Accounting Standards On January 1, 2019, the Company adopted Accounting Standards Update ("ASU") No. 2016-02, Leases, ASU No. 2018-10, Codification Improvements to Topic 842 (Leases) and ASU No. 2018-11, Targeted Improvements to Topic 842 (Leases). The guidance is intended to increase transparency and comparability among companies for leasing transactions, including a requirement for companies that lease assets to recognize on their balance sheets the assets and liabilities for the rights and obligations created by those leases. The guidance also provides for disclosures that allow the users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The Company adopted the guidance on January 1, 2019 using the modified retrospective method without restatement of comparative periods. As such, periods prior to the date of adoption are presented in accordance with ASC 840 - Leases. The Company utilized the available practical expedient that allowed for the Company to not reassess whether existing contracts contain a lease under the new definition of a lease, lease classification for existing leases and whether previously capitalized initial direct costs would qualify for capitalization under the new guidance. The adoption of this guidance had a material impact on the Condensed Consolidated Balance Sheet as of September 30, 2019 due to the recognition of equal right-of-use assets and lease liabilities for the Company's portfolio of operating leases. The right-of-use asset balance was then adjusted by the reclassification of pre-existing prepaid and accrued rent balances from other line items within the Condensed Consolidated Balance Sheet. The adoption had an immaterial impact on the Condensed Consolidated Statement of Comprehensive Income and Condensed Consolidated Statement of Cash Flows for the three and nine months ended September 30, 2019. The adoption had no impact on the Condensed Consolidated Statement of Changes in Stockholders' Equity for the three and nine months ended September 30, 2019. Additional information and disclosures required by the new standard are contained in Note 6 , Leases . On January 1, 2019, the Company adopted ASU No. 2018-02, Income Statement - Reporting Comprehensive Income, which is intended to improve the usefulness of information reported as a result of the Tax Cuts and Jobs Act. The new guidance allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. The adoption of this guidance did not have an impact on the Company's consolidated financial statements.

Revenue (Notes)

Revenue (Notes)	9 Months Ended
	Sep. 30, 2019
Unbilled Receivables, Contract Assets and Liabilities [Line Items]
Revenue Recognition, Multiple-deliverable Arrangements, Description [Policy Text Block]	Executive Search Revenue is recognized as we satisfy our performance obligations by transferring a good or service to a client. Generally, each of our executive search contracts contains one performance obligation which is the process of identifying potentially qualified candidates for a specific client position. In most contracts, the transaction price includes both fixed and variable consideration. Fixed compensation is comprised of a retainer, equal to approximately one-third of the estimated first year compensation for the position to be filled, and indirect expenses, equal to a specified percentage of the retainer, as defined in the contract. The Company generally bills its clients for its retainer and indirect expenses in one-third increments over a three-month period commencing in the month of a client’s acceptance of the contract. If actual compensation of a placed candidate exceeds the original compensation estimate, the Company is often authorized to bill the client for one-third of the excess compensation. The Company refers to this additional billing as uptick revenue. In most contracts, variable consideration is comprised of uptick revenue and direct expenses. The Company bills its clients for uptick revenue upon completion of the executive search, and direct expenses are billed as incurred. The Company estimates uptick revenue at contract inception, based on a portfolio approach, utilizing the expected value method based on a historical analysis of uptick revenue realized in the Company’s geographic regions and industry practices, and initially records a contract’s uptick revenue in an amount that is probable not to result in a significant reversal of cumulative revenue recognized when the actual amount of uptick revenue for that contract is known. Differences between the estimated and actual amounts of variable consideration are recorded when known. The Company does not estimate revenue for direct expenses as it is not materially different than recognizing revenue as direct expenses are incurred. Revenue from our executive search engagement performance obligation is recognized over time as our clients simultaneously receive and consume the benefits provided by the Company's performance. Revenue from executive search engagements is recognized over the expected average period of performance, in proportion to the estimated personnel time incurred to fulfill our obligations under the executive search contract. Revenue is generally recognized over a period of approximately six months. Our executive search contracts contain a replacement guarantee which provides for an additional search to be completed, free of charge except for expense reimbursements, should the candidate presented by the Company be hired by the client and subsequently terminated by the client for performance reasons within a specified period of time. The replacement guarantee is an assurance warranty, which is not a performance obligation under the terms of the executive search contract, as the Company does not provide any services under the terms of the guarantee that transfer benefits to the client in excess of assuring that the identified candidate complies with the agreed-upon specifications. The Company accounts for the replacement guarantee under the relevant warranty guidance in ASC 460 - Guarantees. Heidrick Consulting Revenue is recognized as we satisfy our performance obligations by transferring a good or service to a client. Heidrick Consulting enters into contracts with clients that outline the general terms and conditions of the assignment to provide succession planning, executive assessment, top team and board effectiveness and culture shaping programs. The consideration the Company expects to receive under each contract is generally fixed. Most of our consulting contracts contain one performance obligation, which is the overall process of providing the consulting service requested by the client. The majority of our consulting revenue is recognized over time utilizing both input and output methods. Contracts that contain coaching sessions, training sessions or the completion of assessments are recognized using the output method as each session or assessment is delivered to the client. Contracts that contain general consulting work are recognized using the input method utilizing a measure of progress that is based on time incurred on the project. The Company enters into enterprise agreements with clients to provide a license for online access, via the Company's SD Connect platform, to training and other proprietary material related to the Company's culture shaping programs. The consideration the Company expects to receive under the terms of an enterprise agreement is comprised of a single fixed fee. Our enterprise agreements contain multiple performance obligations, the delivery of materials via SD Connect and material rights related to options to renew enterprise agreements at a significant discount. The Company allocates the transaction price to the performance obligations in the contract on a stand-alone selling price basis. The stand-alone selling price for the initial term of the enterprise agreement is outlined in the contract and is equal to the price paid by the client for the agreement over the initial term of the contract. The stand-alone selling price for the options to renew, or material right, are not directly observable and must be estimated. This estimate is required to reflect the discount the client would obtain when exercising the option to renew, adjusted for the likelihood that the option will be exercised. The Company estimates the likelihood of renewal using a historical analysis of client renewals. Access to SD Connect represents a right to access the Company’s intellectual property that the client simultaneously receives and consumes as the Company performs under the agreement, and therefore the Company recognizes revenue over time. Given the continuous nature of this commitment, the Company utilizes straight-line ratable revenue recognition over the estimated subscription period as the Company's clients will receive and consume the benefits from SD Connect equally throughout the contract period. Revenue related to client renewals of enterprise agreements is recognized over the term of the renewal, which is generally twelve months. Enterprise agreements do not comprise a significant portion of the Company's revenue. Contract Balances Contract assets and liabilities are reported in a net position on a contract-by-contract basis at the end of each reporting period. Contract assets and liabilities are classified as current due to the nature of the Company's contracts, which are completed within one year. Contract assets are included within Other Current Assets on the Condensed Consolidated Balance Sheets. Unbilled receivables: Unbilled revenue represents contract assets from revenue recognized over time in excess of the amount billed to the client and the amount billed to the client is solely dependent upon the passage of time. This amount includes revenue recognized in excess of billed executive search retainers and Heidrick Consulting fees. Contract assets: Contract assets represent revenue recognized over time in excess of the amount billed to the client and the amount billed to the client is not solely subject to the passage of time. This amount primarily includes revenue recognized for upticks and contingent placement fees in executive search contracts. Deferred revenue: Contract liabilities consist of deferred revenue, which is equal to billings in excess of revenue recognized. The following table outlines the changes in our contract asset and liability balances during the period: December 31, September 30, Change Contract assets Unbilled receivables $ 8,684 $ 9,090 $ 406 Contract assets 15,291 13,686 (1,605 ) Total contract assets 23,975 22,776 (1,199 ) Contract liabilities Deferred revenue $ 40,673 $ 40,434 $ (239 ) During the nine months ended September 30, 2019 , we recognized revenue of $33.8 million that was included in the contract liabilities balance at the beginning of the period. The amount of revenue recognized during the nine months ended September 30, 2019 , from performance obligations partially satisfied in previous periods as a result of changes in the estimates of variable consideration was $17.8 million . Each of the Company's contracts has an expected duration of one year or less. Accordingly, the Company has elected to utilize the available practical expedient related to the disclosure of the transaction price allocated to the remaining performance obligations under its contracts. The Company has also elected the available practical expedients related to adjusting for the effects of a significant financing component and the capitalization of contract acquisition costs. The Company charges and collects from its clients, sales tax and value added taxes as required by certain jurisdictions. The Company has made an accounting policy election to exclude these items from the transaction price in its contracts.

Allowance for Doubtful Accounts

Allowance for Doubtful Accounts	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Allowance for Doubtful Accounts	The activity of the allowance for doubtful accounts is as follows: Balance at December 31, 2018 $ 3,502 Provision charged to income 3,058 Write-offs, net of recoveries (2,101 ) Foreign currency translation (72 ) Balance at September 30, 2019 $ 4,387

Property and Equipment, net

Property and Equipment, net	9 Months Ended
	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Property and Equipment, net	The components of the Company’s property and equipment are as follows: September 30, December 31, Leasehold improvements $ 45,839 $ 48,455 Office furniture, fixtures and equipment 17,441 17,919 Computer equipment and software 27,243 27,063 Property and equipment, gross 90,523 93,437 Accumulated depreciation (61,167 ) (59,566 ) Property and equipment, net $ 29,356 $ 33,871 Depreciation expense for the three months ended September 30, 2019 and 2018 was $2.4 million and $2.7 million , respectively. Depreciation expense for the nine months ended September 30, 2019 and 2018 was $7.3 million and $8.3 million , respectively.

Leases (Notes)

Leases (Notes)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	The Company's lease portfolio is comprised of operating leases for office space and equipment. The majority of the Company's leases include both lease and non-lease components, which the Company accounts for differently depending on the underlying class of asset. Certain of the Company's leases include one or more options to renew or terminate the lease at the Company's discretion. Generally, the renewal and termination options are not included in the right-of-use assets and lease liabilities as they are not reasonably certain of exercise. The Company regularly evaluates the renewal and termination options and when they are reasonably certain of exercise, includes the renewal or termination option in our lease term. As most of the Company's leases do not provide an implicit interest rate, the Company utilizes its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The Company has a centrally managed treasury function; therefore, a portfolio approach is applied in determining the incremental borrowing rate. The incremental borrowing rate is the rate of interest that the Company would have to pay to borrow on a fully collateralized basis over a similar term in an amount equal to the total lease payments in a similar economic environment. Office leases have remaining lease terms that range from less than one year to 7 years , some of which also include options to extend or terminate the lease. Most office leases contain both fixed and variable lease payments. Variable lease costs consist primarily of rent escalations based on an established index or rate and taxes, insurance, and common area or other maintenance costs, which are paid based on actual costs incurred by the lessor. The Company has elected to utilize the available practical expedient to not separate lease and non-lease components for office leases. Equipment leases, which are comprised of vehicle and office equipment leases, have remaining terms that range from less than one year to 4.7 years , some of which also include options to extend or terminate the lease. The Company's equipment leases do not contain variable lease payments. The Company separates the lease and non-lease components for its equipment leases. Equipment leases do not comprise a significant portion of the Company's lease portfolio. Lease cost components included within General and Administrative Expenses in our Condensed Consolidated Statements of Comprehensive Income were as follows: Three Months Ended Nine Months Ended Operating lease cost $ 6,180 $ 18,660 Variable lease cost 2,128 6,042 Total lease cost $ 8,308 $ 24,702 Supplemental cash flow information related to the Company's operating leases is as follows: Nine Months Ended Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 26,879 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 11,385 The weighted average remaining lease term and weighted average discount rate for our operating leases as of September 30, 2019 is as follows: September 30, 2019 Weighted Average Remaining Lease Term Operating leases 4.5 years Weighted Average Discount Rate Operating leases 3.97 % The future maturities of the Company's operating lease liabilities as of September 30, 2019 , for the years ended December 31 is as follows: Operating Lease Maturity 2019 $ 9,441 2020 30,518 2021 25,662 2022 22,097 2023 19,189 Thereafter 13,258 Total lease payments 120,165 Less: Interest (12,631 ) Present value of lease liabilities $ 107,534

Acquisitions (Notes)

Acquisitions (Notes)	9 Months Ended
	Sep. 30, 2019
Business Acquisition [Line Items]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	8 . Acquisitions In September 2019, the Company acquired 2GET Holdings Limited ("2GET"), a Brazil-based provider of executive search services, and its wholly owned subsidiaries. Under the terms of the purchase agreement, the Company paid $5.2 million of initial consideration for substantially all of the outstanding equity of 2GET subject to a final working capital settlement. The acquisition was funded with $4.1 million of existing cash at closing and $1.1 million of the Company's common stock to be transferred in October 2019. The former owners of 2GET are eligible to receive additional cash consideration, which the Company estimates to be between $5.0 million and $15.0 million , based on the achievement of certain revenue and EBITDA milestones for the period from acquisition through 2023. When estimating the present value of future cash consideration, the Company accrued $5.9 million as of the acquisition date. The Company recorded an estimated $3.0 million of intangible assets and $7.5 million of goodwill. The goodwill is primarily related to the acquired workforce and strategic fit. The fair value estimate of assets acquired and liabilities assumed, including the earnout liability, identifiable intangible assets and goodwill, is pending completion. The Company expects to finalize its estimates of fair value during the three months ended December 31, 2019.

Financial Instruments and Fair

Financial Instruments and Fair Value	9 Months Ended
	Sep. 30, 2019
Investments Schedule [Abstract]
Investments	Cash, Cash Equivalents and Marketable Securities The Company's investments in marketable debt securities, which consist of U.S. Treasury bills and commercial paper, are classified and accounted for as available-for-sale. The Company classifies its marketable debt securities as either short-term or long-term based on each instrument's underlying contractual maturity date. Unrealized gains and losses on marketable debt securities classified as available-for-sale are recognized in Accumulated other comprehensive income in the Condensed Consolidated Balance Sheets until realized. The Company's cash, cash equivalents, and marketable securities by significant investment category are as follows: Fair Value Balance Sheet Classification Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and Cash Equivalents Marketable Securities Balance at September 30, 2019 Cash $ 114,467 $ — Level 1 (1) : Money market funds 15,595 — — 15,595 15,595 — U.S. Treasury securities 82,386 12 — 82,398 46,310 36,088 Total Level 1 97,981 12 — 97,993 61,905 36,088 Level 2 (2) : Commercial paper 6,478 — — 6,478 — 6,478 Total $ 104,459 $ 12 $ — $ 104,471 $ 176,372 $ 42,566 Fair Value Balance Sheet Classification Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and Cash Equivalents Marketable Securities Balance at December 31, 2018 Cash $ 279,829 $ — Level 1 (1) : Money market funds 77 — — 77 77 — Total $ 77 $ — $ — $ 77 $ 279,906 $ — (1) Level 1 – Quoted prices in active markets for identical assets and liabilities. (2) Level 2 – Quoted prices in active markets for similar assets and liabilities, or other inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. Investments, Assets Designated for Retirement and Pension Plans and Associated Liabilities The Company has a U.S. non-qualified deferred compensation plan that consists primarily of U.S. marketable securities and mutual funds. The aggregate cost basis for these investments was $16.5 million and $14.6 million as of September 30, 2019 and December 31, 2018 , respectively. The Company also maintains a pension plan for certain current and former employees in Germany. The pensions are individually fixed Euro amounts that vary depending on the function and the eligible years of service of the employee. The Company’s investment strategy is to support its pension obligations through reinsurance contracts. The BaFin—German Federal Financial Supervisory Authority—supervises the insurance companies and the reinsurance contracts. The BaFin requires each reinsurance contract to guarantee a fixed minimum return. The Company’s pension benefits are fully reinsured by group insurance contracts with ERGO Lebensversicherung AG, and the group insurance contracts are measured in accordance with BaFin guidelines (including mortality tables and discount rates) which are considered Level 2 inputs. The following tables provide a summary of the fair value measurements for each major category of investments, assets designated for retirement and pension plans and associated liabilities measured at fair value on a recurring basis: Balance Sheet Classification Fair Value Other Current Assets Assets Designated for Retirement and Pension Plans Investments Other Current Liabilities Retirement and Pension Plans Balance at September 30, 2019 Level 1 (1) : U.S. non-qualified deferred compensation plan $ 23,807 $ — $ — $ 23,807 $ — $ — Level 2 (2) : Retirement and pension plan assets 15,571 1,282 14,289 — — — Pension benefit obligation (19,870 ) — — — (1,282 ) (18,588 ) Total Level 2 (4,299 ) 1,282 14,289 — (1,282 ) (18,588 ) Total $ 19,508 $ 1,282 $ 14,289 $ 23,807 $ (1,282 ) $ (18,588 ) Balance Sheet Classification Fair Value Other Current Assets Assets Designated for Retirement and Pension Plans Investments Other Current Liabilities Retirement and Pension Plans Balance at December 31, 2018 Level 1 (1) : U.S. non-qualified deferred compensation plan $ 19,442 $ — $ — $ 19,442 $ — $ — Level 2 (2) : Retirement and pension plan assets 16,384 1,349 15,035 — — — Pension benefit obligation (20,908 ) — — — (1,349 ) (19,559 ) Total Level 2 (4,524 ) 1,349 15,035 — (1,349 ) (19,559 ) Total $ 14,918 $ 1,349 $ 15,035 $ 19,442 $ (1,349 ) $ (19,559 ) (1) Level 1 – Quoted prices in active markets for identical assets and liabilities. (2) Level 2 – Quoted prices in active markets for similar assets and liabilities, or other inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. Contingent Consideration The former owners of the Company's prior year acquisitions are eligible to receive additional cash consideration based on the attainment of certain operating metrics in the periods subsequent to acquisition. Contingent consideration is valued using significant inputs that are not observable in the market which are defined as Level 3 inputs pursuant to fair value measurement accounting. The Company determines the fair value of contingent consideration using discounted cash flow models. The following table provides a reconciliation of the beginning and ending balance of Level 3 liabilities for the nine months ended September 30, 2019 : Acquisition Balance at December 31, 2018 $ (6,627 ) Acquisition earnouts (Note 8) (5,862 ) Earnout accretion (495 ) Earnout payments 3,009 Earnout adjustments (1,135 ) Foreign currency translation 209 Balance at September 30, 2019 $ (10,901 )

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill The Company's goodwill by segment is as follows: September 30, December 31, Executive Search Americas $ 96,012 $ 88,410 Europe 23,949 24,924 Asia Pacific 8,325 8,758 Total Executive Search 128,286 122,092 Heidrick Consulting 36,257 36,257 Goodwill, gross 164,543 158,349 Accumulated impairment (36,257 ) (36,257 ) Goodwill, net $ 128,286 $ 122,092 Changes in the carrying amount of goodwill by segment for the nine months ended September 30, 2019 , are as follows: Executive Search Americas Europe Asia Pacific Heidrick Consulting Total Gross goodwill at December 31, 2018 $ 88,410 $ 24,924 $ 8,758 $ 36,257 $ 158,349 Accumulated impairment — — — (36,257 ) (36,257 ) Net goodwill at December 31, 2018 88,410 24,924 8,758 — 122,092 2GET acquisition 7,504 — — — 7,504 Foreign currency translation 98 (975 ) (433 ) — (1,310 ) Net goodwill at September 30, 2019 $ 96,012 $ 23,949 $ 8,325 $ — $ 128,286 In September 2019 the Company acquired 2GET and included an estimate of the fair value of the acquired assets and liabilities as of the acquisition date in the Condensed Consolidated Balance Sheets. The Company included an estimated $7.5 million of goodwill related the acquisition in the Americas segment. The Company's estimate of the fair value of the acquired assets and liabilities is pending completion and is expected to be finalized during the three months ended December 31, 2019. Other Intangible Assets, net The Company’s other intangible assets, net by segment, are as follows: September 30, December 31, Executive Search Americas $ 2,951 $ 52 Europe 1,412 2,086 Asia Pacific 65 78 Total Executive Search 4,428 2,216 Heidrick Consulting — — Total other intangible assets, net $ 4,428 $ 2,216 The Company recorded an estimate for customer relationships in the Americas segment of $3.0 million related to the acquisition of 2GET. The Company's estimate of the fair value of the acquired assets and liabilities is pending completion and is expected to be finalized during the three months ended December 31, 2019. The carrying amount of amortizable intangible assets and the related accumulated amortization are as follows: Weighted September 30, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Client relationships 6.2 $ 18,628 $ (14,200 ) $ 4,428 $ 15,910 $ (13,694 ) $ 2,216 Intangible asset amortization expense for the three months ended September 30, 2019 and 2018 was $0.2 million and $0.4 million , respectively. Intangible asset amortization expense for the nine months ended September 30, 2019 and 2018 was $0.7 million and $1.2 million , respectively. The Company's estimated future amortization expense related to intangible assets as of September 30, 2019 , for the years ended December 31 is as follows: Estimated Future Amortization 2019 $ 287 2020 998 2021 833 2022 723 2023 632 Thereafter 955 Total $ 4,428

Other Current Assets and Liabil

Other Current Assets and Liabilities and Non-current Liabilities	9 Months Ended
	Sep. 30, 2019
Other Liabilities Disclosure [Abstract]
Other Non-Current Liabilities	The components of other current assets are as follows: September 30, December 31, Contract assets $ 22,776 $ 23,975 Other 5,190 5,623 Total other current assets $ 27,966 $ 29,598 The components of other non-current liabilities are as follows: September 30, December 31, Premise related costs $ 2,557 $ 15,473 Accrued earnout payments 5,862 — Other 2,089 1,950 Total other non-current liabilities $ 10,508 $ 17,423

Line of Credit

Line of Credit	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Line of Credit	On October 26, 2018, the Company entered into a new Credit Agreement (the "2018 Credit Agreement") to replace the Second Amended and Restated Credit Agreement (the "Restated Credit Agreement") executed on June 30, 2015. The 2018 Credit Agreement provides the Company with a senior unsecured revolving line of credit with an aggregate commitment of $175 million , which includes a sublimit of $25 million for letters of credit, and a $10 million swingline loan sublimit. The agreement also includes a $75 million expansion feature. The 2018 Credit Agreement will mature in October 2023. Borrowings under the 2018 Credit Agreement bear interest at the Company's election of the Alternate Base Rate (as defined in the 2018 Credit Agreement) or Adjusted LIBOR (as defined in the 2018 Credit Agreement) plus a spread as determined by the Company's leverage ratio. Borrowings under the 2018 Credit Agreement may be used for working capital, capital expenditures, Permitted Acquisitions (as defined in the 2018 Credit Agreement) and for other general purposes of the Company and its subsidiaries. The obligations under the 2018 Credit Agreement are guaranteed by certain of the Company's subsidiaries. The Company capitalized approximately $1.0 million of loan acquisition costs related to the 2018 Credit Agreement, which will be amortized over the term of the agreement. Before October 26, 2018, the Company was party to the Restated Credit Agreement, which was executed on June 30, 2015. The Restated Credit Agreement provided a single senior unsecured revolving line of credit with an aggregate commitment of up to $100 million , which included a sublimit of $25 million for letters of credit, and a $50 million expansion feature (the “Replacement Facility”). Borrowings under the Restated Credit Agreement bore interest at the Company's election of the existing Alternate Base Rate (as defined in the Restated Credit Agreement) or Adjusted LIBOR Rate (as defined in the Restated Credit Agreement) plus a spread as determined by the Company's leverage ratio. During the three months ended March 31, 2018, the Company borrowed $20 million under the Restated Credit Agreement and elected the Adjusted LIBOR Rate. The Company subsequently repaid $8 million during the three months ended March 31, 2018 and $12 million during the three months ended June 30, 2018. As of September 30, 2019 , and December 31, 2018 , the Company had no outstanding borrowings. The Company was in compliance with the financial and other covenants under both facilities and no event of default existed.

Stock-based Compensation

Stock-based Compensation	9 Months Ended
	Sep. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	The Company’s Second Amended and Restated 2012 Heidrick & Struggles GlobalShare Program (the “2012 Program”) provides for grants of stock options, stock appreciation rights, and other stock-based awards that are valued based upon the grant date fair value of shares. These awards may be granted to directors, selected employees and independent contractors. The 2012 Program originally authorized 1,300,000 shares of Common Stock for issuance pursuant to awards under the plan. On May 22, 2014 , the stockholders of the Company approved an amendment to the 2012 Program to increase the number of shares of Common Stock reserved for issuance under the 2012 Program by 700,000 shares. On May 24, 2018 , the stockholders of the Company approved an amendment to the 2012 Program to increase the number of shares of Common Stock reserved for issuance under the 2012 Program by 850,000 shares. As of September 30, 2019 , 2,495,928 awards have been issued under the 2012 Program and 1,032,494 shares remain available for future awards, including 678,422 forfeited awards. The 2012 Program provides that no awards can be granted after May 24, 2028 . The Company measures its stock-based compensation costs based on the grant date fair value of the awards and recognizes these costs in the financial statements over the requisite service period. A summary of information with respect to stock-based compensation is as follows: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Salaries and benefits (1) $ 3,294 $ 2,911 $ 7,941 $ 6,200 General and administrative expenses — — 460 563 Income tax benefit related to stock-based compensation included in net income 870 771 2,219 1,792 (1) Includes $0.8 million and $1.2 million of expense related to cash settled restricted stock units for the three and nine months ended September 30, 2019 , respectively. Includes $0.4 million of expense related to cash settled restricted stock units for the three and nine months ended September 30, 2018. Restricted Stock Units Restricted stock units are generally subject to ratable vesting over a three-year period. Beginning in 2018, a portion of the Company's restricted stock units are subject to ratable vesting over a four-year period. Compensation expense related to service-based restricted stock units is recognized on a straight-line basis over the vesting period. Restricted stock unit activity for the nine months ended September 30, 2019 is as follows: Number of Weighted- Outstanding on December 31, 2018 512,446 $ 28.83 Granted 270,488 33.55 Vested and converted to common stock (175,792 ) 24.19 Forfeited (3,453 ) 34.43 Outstanding on September 30, 2019 603,689 $ 32.27 As of September 30, 2019 , there was $11.4 million of pre-tax unrecognized compensation expense related to unvested restricted stock units, which is expected to be recognized over a weighted average of 2.8 years . Performance Stock Units The Company grants performance stock units to certain of its senior executives. The performance stock units are generally subject to a cliff vesting at the end of a three -year period. The vesting will vary between 0% and 200% based on the attainment of operating income goals over the three -year vesting period. The performance stock units are expensed on a straight-line basis over the three -year vesting period. During the nine months ended September 30, 2019 , performance stock units were granted to certain employees of the Company and are subject to a cliff vesting period of three years and certain other performance conditions. Half of award is based on the achievement of certain operating margin thresholds and half of the award is based on the Company's total shareholder return, relative to a peer group. The fair value of the awards based on total shareholder return was determined using the Monte-Carlo simulation model. A Monte Carlo simulation model uses stock price volatility and other variables to estimate the probability of satisfying the performance conditions and the resulting fair value of the award. Performance stock unit activity for the nine months ended September 30, 2019 is as follows: Number of Stock Units Weighted- Outstanding on December 31, 2018 197,117 $ 27.58 Granted 64,701 37.62 Vested and converted to common stock (99,219 ) 25.04 Forfeited — — Outstanding on September 30, 2019 162,599 $ 33.13 As of September 30, 2019 , there was $3.4 million of pre-tax unrecognized compensation expense related to unvested performance stock units, which is expected to be recognized over a weighted average of 2.1 years . Phantom Stock Units Phantom stock units are grants of phantom stock with respect to shares of the Company's common stock that are settled in cash and are subject to various restrictions, including restrictions on transferability, vesting and forfeiture provisions. Shares of phantom stock that do not vest for any reason will be forfeited by the recipient and will revert to the Company. Phantom stock units were granted to certain employees of the Company and are subject to vesting over a period of four years and certain other conditions, including continued service to the Company. As a result of the cash-settlement feature of the awards, the Company considers the awards to be liability awards, which are measured at fair value at each reporting date and the vested portion of the award is recognized as a liability to the extent that the service condition is deemed probable. The fair value of the phantom stock awards on the balance sheet date, was determined using the closing share price of the Company's common stock on that date. The Company recorded phantom stock-based compensation expense of $0.8 million and $1.2 million during the three and nine months ended September 30, 2019 , respectively. The Company recorded phantom stock-based compensation expense of $0.4 million during the three and nine months ended September 30, 2018. Phantom stock unit activity for the nine months ended September 30, 2019 is as follows: Number of Stock Units Outstanding on December 31, 2018 111,673 Granted 154,387 Vested and converted to common stock — Forfeited — Outstanding on September 30, 2019 266,060 As of September 30, 2019 , there was $5.2 million of pre-tax unrecognized compensation expense related to unvested phantom stock units, which is expected to be recognized over a weighted average of 3.6 years .

Restructuring (Notes)

Restructuring (Notes)	9 Months Ended
	Sep. 30, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Activities Disclosure [Text Block]	During the three months ended September 30, 2019, the Company recorded restructuring charges of $4.1 million related to the closing of the Company's legacy Brazil operations due to the acquisition of 2GET (see Note 8, Acquisitions ). The restructuring charges primarily consist of employee-related costs for the Company's existing Brazil operations. The America's incurred $4.1 million in restructuring charges, while Global Operations Support incurred less than $0.1 million . In 2017, the Company recorded restructuring charges of $15.7 million in connection with initiatives to reduce overall costs and improve operational efficiencies. The primary components of the restructuring included: the elimination of two executive officer roles for a flatter leadership structure, a workforce reduction as the firm aligned its support resources to better meet operational needs and recognize synergies with the combination of Leadership Consulting and Culture Shaping, a reduction of the firm’s real estate expenses and support costs by consolidating or closing three of its locations across its global footprint, and the acceleration of future expenses under certain contractual obligations. Changes to the accrual for restructuring charges for the nine months ended September 30, 2019 , are as follows: Employee Related Other Total Outstanding on December 31, 2018 $ 1,269 $ 17 $ 1,286 Restructuring charges 4,130 — 4,130 Cash payments (1,554 ) — (1,554 ) Non cash write offs — (17 ) (17 ) Other 4 — 4 Exchange rate fluctuations (74 ) — (74 ) Outstanding on September 30, 2019 $ 3,775 $ — $ 3,775

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	The Company reported income before taxes of $14.8 million and an income tax provision of $4.9 million for the three months ended September 30, 2019 . The Company reported income before taxes of $23.2 million and an income tax provision of $6.7 million for the three months ended September 30, 2018 . The effective tax rates for the three months ended September 30, 2019 and 2018 , were 32.9% and 29.0% , respectively. The effective tax rate for the three months ended September 30, 2019 was impacted by one-time items and the mix of income. The effective tax rate for the three months ended September 30, 2018 was impacted by one-time items and the Tax Cuts and Jobs Act enacted on December 22, 2017 in the United States. The Company reported income before taxes of $53.1 million and an income tax provision of $16.8 million for the nine months ended September 30, 2019 . The Company reported income before taxes of $54.5 million and an income tax provision of $16.4 million for the nine months ended September 30, 2018 . The effective tax rates for the nine months ended September 30, 2019 and 2018 , were 31.7% and 30.1% , respectively. The effective tax rate for the nine months ended September 30, 2019 was impacted by one-time items and the mix of income. The effective tax rate for the nine months ended September 30, 2018 was impacted by one-time items and the Tax Cuts and Jobs Act enacted on December 22, 2017 in the United States. The Company estimates that its effective tax rate for the year ended December 31, 2019, will be between 31% and 34% . The full year effective rate for 2019 is primarily the result of one-time items and the mix of income.

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Changes in Accumulated Other Comprehensive Income	The changes in Accumulated other comprehensive income (“AOCI”) by component for the nine months ended September 30, 2019 is summarized below: Available- Foreign Pension AOCI Balance at December 31, 2018 $ — $ 5,258 $ (1,196 ) $ 4,062 Other comprehensive income before classification, net of tax 12 (1,024 ) — (1,012 ) Net current period other comprehensive income 12 (1,024 ) — (1,012 ) Balance at September 30, 2019 $ 12 $ 4,234 $ (1,196 ) $ 3,050

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Information	In 2018, the Company completed the integration of its Leadership Consulting and Culture Shaping businesses into one combined service offering, Heidrick Consulting. In conjunction with the integration, the Company reorganized its Management Committee, which the Company considers to be its chief operating decision maker, so as to regularly assess performance and make resource allocations decisions for the Heidrick Consulting business. Therefore, the Company now reports its former Leadership Consulting and Culture Shaping operating segments as one operating segment, Heidrick Consulting. The Company has four operating segments. The executive search business operates in the Americas, Europe (which includes Africa) and Asia Pacific (which includes the Middle East), and the Heidrick Consulting business operates globally. For segment purposes, reimbursements of out-of-pocket expenses classified as revenue and other operating income are reported separately and, therefore, are not included in the results of each segment. The Company believes that analyzing trends in revenue before reimbursements (net revenue), analyzing operating expenses as a percentage of net revenue, and analyzing operating income, more appropriately reflect its core operations. The revenue and operating income (loss) by segment are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Revenue Executive Search Americas $ 108,878 $ 106,504 $ 308,700 $ 295,499 Europe 34,827 37,452 103,244 110,419 Asia Pacific 22,784 28,095 71,394 78,460 Total Executive Search 166,489 172,051 483,338 484,378 Heidrick Consulting 15,685 15,537 43,552 46,340 Revenue before reimbursements (net revenue) 182,174 187,588 526,890 530,718 Reimbursements 4,344 4,753 14,075 13,970 Total revenue $ 186,518 $ 192,341 $ 540,965 $ 544,688 Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Operating income (loss) Executive Search Americas (1) $ 23,211 $ 23,341 $ 74,211 $ 69,988 Europe 466 904 3,788 6,453 Asia Pacific 2,421 6,414 10,642 13,608 Total Executive Search 26,098 30,659 88,641 90,049 Heidrick Consulting (3,150 ) (1,761 ) (12,770 ) (10,988 ) Total segment operating income 22,948 28,898 75,871 79,061 Global Operations Support (1) (8,476 ) (8,315 ) (26,655 ) (26,896 ) Total operating income $ 14,472 $ 20,583 $ 49,216 $ 52,165 (1) 2019 includes restructuring charges of $4.1 million in the Americas and less than $0.1 million in Global Operations Support.

Guarantees

Guarantees	9 Months Ended
	Sep. 30, 2019
Guarantees [Abstract]
Guarantees	The Company has utilized letters of credit to support certain obligations, primarily for its office lease agreements in Europe and Asia Pacific. The letters of credit were made to secure the respective agreements and are for the terms of the agreements, which extend through 2024 . For each letter of credit issued, the Company would have to use cash to fulfill the obligation if there is a default on a payment. The maximum amount of undiscounted payments the Company would be required to make in the event of default on all outstanding letters of credit is approximately $2.6 million as of September 30, 2019 . The Company has not accrued for these arrangements as no event of default exists or is expected to exist.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Loss Contingencies [Line Items]
Contingencies Disclosure [Text Block]	Litigation The Company has contingent liabilities from various pending claims and litigation matters arising in the ordinary course of the Company’s business, some of which involve claims for damages that are substantial in amount. Some of these matters are covered by insurance. Based upon information currently available, the Company believes the ultimate resolution of such claims and litigation will not have a material adverse effect on its financial condition, results of operations or liquidity.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Summary of Significant Accounting Policies [Abstract]
Lessee, Leases [Policy Text Block]	Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in Operating Lease Right-of-Use Assets , Operating Lease Liabilities - Current and Operating Lease Liabilities - Non-Current in our Condensed Consolidated Balance Sheets. The Company does not have any leases that meet the finance lease criteria. Right-of-use assets represent the Company's right to use an underlying asset for the lease term and lease liabilities represent the Company's obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized on the commencement date based on the present value of lease payments over the lease term. As most of the Company's leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The operating lease right-of-use asset also includes any lease payments made in advance and any accrued rent expense balances. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term.
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition See Note 3 , Revenue .
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted Cash Historically, the Company had lease agreements and business licenses with terms that required the Company to restrict cash through the termination dates of the agreements. Current and non-current restricted cash is included in Other current assets and Other non-current assets , respectively, in the Condensed Consolidated Balance Sheets. The following table provides a reconciliation of the cash and cash equivalents between the Condensed Consolidated Balance Sheets and the Condensed Consolidated Statement of Cash Flows as of September 30, 2019 and 2018 , and December 31, 2018 and 2017 : September 30, December 31, 2019 2018 2018 2017 Cash and cash equivalents $ 176,372 $ 164,216 $ 279,906 $ 207,534 Restricted cash included within other current assets — 598 108 526 Restricted cash included within other non-current assets — — 248 102 Total cash, cash equivalents and restricted cash $ 176,372 $ 164,814 $ 280,262 $ 208,162
Reclassification, Policy [Policy Text Block]
Earnings Per Share, Policy [Policy Text Block]	Earnings per Common Share Basic earnings per common share is computed by dividing net income by weighted average common shares outstanding for the period. Diluted earnings per share reflect the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted. Common equivalent shares are excluded from the determination of diluted earnings per share in periods in which they have an anti-dilutive effect. The following table sets forth the computation of basic and diluted earnings per share: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Net income $ 9,947 $ 16,469 $ 36,314 $ 38,100 Weighted average shares outstanding: Basic 19,127 18,954 19,084 18,905 Effect of dilutive securities: Restricted stock units 195 278 283 345 Performance stock units 106 169 151 194 Diluted 19,428 19,401 19,518 19,444 Basic earnings per share $ 0.52 $ 0.87 $ 1.90 $ 2.02 Diluted earnings per share $ 0.51 $ 0.85 $ 1.86 $ 1.96
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted Financial Accounting Standards On January 1, 2019, the Company adopted Accounting Standards Update ("ASU") No. 2016-02, Leases, ASU No. 2018-10, Codification Improvements to Topic 842 (Leases) and ASU No. 2018-11, Targeted Improvements to Topic 842 (Leases). The guidance is intended to increase transparency and comparability among companies for leasing transactions, including a requirement for companies that lease assets to recognize on their balance sheets the assets and liabilities for the rights and obligations created by those leases. The guidance also provides for disclosures that allow the users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The Company adopted the guidance on January 1, 2019 using the modified retrospective method without restatement of comparative periods. As such, periods prior to the date of adoption are presented in accordance with ASC 840 - Leases. The Company utilized the available practical expedient that allowed for the Company to not reassess whether existing contracts contain a lease under the new definition of a lease, lease classification for existing leases and whether previously capitalized initial direct costs would qualify for capitalization under the new guidance. The adoption of this guidance had a material impact on the Condensed Consolidated Balance Sheet as of September 30, 2019 due to the recognition of equal right-of-use assets and lease liabilities for the Company's portfolio of operating leases. The right-of-use asset balance was then adjusted by the reclassification of pre-existing prepaid and accrued rent balances from other line items within the Condensed Consolidated Balance Sheet. The adoption had an immaterial impact on the Condensed Consolidated Statement of Comprehensive Income and Condensed Consolidated Statement of Cash Flows for the three and nine months ended September 30, 2019. The adoption had no impact on the Condensed Consolidated Statement of Changes in Stockholders' Equity for the three and nine months ended September 30, 2019. Additional information and disclosures required by the new standard are contained in Note 6 , Leases . On January 1, 2019, the Company adopted ASU No. 2018-02, Income Statement - Reporting Comprehensive Income, which is intended to improve the usefulness of information reported as a result of the Tax Cuts and Jobs Act. The new guidance allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. The adoption of this guidance did not have an impact on the Company's consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table sets forth the computation of basic and diluted earnings per share: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Net income $ 9,947 $ 16,469 $ 36,314 $ 38,100 Weighted average shares outstanding: Basic 19,127 18,954 19,084 18,905 Effect of dilutive securities: Restricted stock units 195 278 283 345 Performance stock units 106 169 151 194 Diluted 19,428 19,401 19,518 19,444 Basic earnings per share $ 0.52 $ 0.87 $ 1.90 $ 2.02 Diluted earnings per share $ 0.51 $ 0.85 $ 1.86 $ 1.96

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Restricted Cash (Tables)	9 Months Ended
	Sep. 30, 2019
Cash and Cash Equivalents [Abstract]
Schedule of Cash, Cash Equivalents, and Restricted Cash [Table Text Block]	The following table provides a reconciliation of the cash and cash equivalents between the Condensed Consolidated Balance Sheets and the Condensed Consolidated Statement of Cash Flows as of September 30, 2019 and 2018 , and December 31, 2018 and 2017 : September 30, December 31, 2019 2018 2018 2017 Cash and cash equivalents $ 176,372 $ 164,216 $ 279,906 $ 207,534 Restricted cash included within other current assets — 598 108 526 Restricted cash included within other non-current assets — — 248 102 Total cash, cash equivalents and restricted cash $ 176,372 $ 164,814 $ 280,262 $ 208,162

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Unbilled Receivables, Contract Assets and Liabilities [Line Items]
Unbilled Receivables, Contract Assets and Liabilities [Table Text Block]	The following table outlines the changes in our contract asset and liability balances during the period: December 31, September 30, Change Contract assets Unbilled receivables $ 8,684 $ 9,090 $ 406 Contract assets 15,291 13,686 (1,605 ) Total contract assets 23,975 22,776 (1,199 ) Contract liabilities Deferred revenue $ 40,673 $ 40,434 $ (239 )

Allowance for Doubtful Accoun_2

Allowance for Doubtful Accounts (Tables)	9 Months Ended
	Sep. 30, 2019
Schedule of Allowance for Doubtful Accounts Receivable [Line Items]
Schedule of Allowance for Doubtful Accounts Receivable [Table Text Block]	The activity of the allowance for doubtful accounts is as follows: Balance at December 31, 2018 $ 3,502 Provision charged to income 3,058 Write-offs, net of recoveries (2,101 ) Foreign currency translation (72 ) Balance at September 30, 2019 $ 4,387

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	9 Months Ended
	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Components of Company's Property and Equipment	The components of the Company’s property and equipment are as follows: September 30, December 31, Leasehold improvements $ 45,839 $ 48,455 Office furniture, fixtures and equipment 17,441 17,919 Computer equipment and software 27,243 27,063 Property and equipment, gross 90,523 93,437 Accumulated depreciation (61,167 ) (59,566 ) Property and equipment, net $ 29,356 $ 33,871

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Lease, Cost [Table Text Block]	Lease cost components included within General and Administrative Expenses in our Condensed Consolidated Statements of Comprehensive Income were as follows: Three Months Ended Nine Months Ended Operating lease cost $ 6,180 $ 18,660 Variable lease cost 2,128 6,042 Total lease cost $ 8,308 $ 24,702
Lessee Operating Leases Supplemental Cash Flow Information and Noncash Activity[Table Text Block]	Supplemental cash flow information related to the Company's operating leases is as follows: Nine Months Ended Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 26,879 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 11,385
Lessee Operating Lease Weighted Averages [Table Text Block]	The weighted average remaining lease term and weighted average discount rate for our operating leases as of September 30, 2019 is as follows: September 30, 2019 Weighted Average Remaining Lease Term Operating leases 4.5 years Weighted Average Discount Rate Operating leases 3.97 %
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	The future maturities of the Company's operating lease liabilities as of September 30, 2019 , for the years ended December 31 is as follows: Operating Lease Maturity 2019 $ 9,441 2020 30,518 2021 25,662 2022 22,097 2023 19,189 Thereafter 13,258 Total lease payments 120,165 Less: Interest (12,631 ) Present value of lease liabilities $ 107,534

Financial Instruments and Fai_2

Financial Instruments and Fair Value(Tables)	9 Months Ended
	Sep. 30, 2019
Investments Schedule [Abstract]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Table Text Block]	The following tables provide a summary of the fair value measurements for each major category of investments, assets designated for retirement and pension plans and associated liabilities measured at fair value on a recurring basis: Balance Sheet Classification Fair Value Other Current Assets Assets Designated for Retirement and Pension Plans Investments Other Current Liabilities Retirement and Pension Plans Balance at September 30, 2019 Level 1 (1) : U.S. non-qualified deferred compensation plan $ 23,807 $ — $ — $ 23,807 $ — $ — Level 2 (2) : Retirement and pension plan assets 15,571 1,282 14,289 — — — Pension benefit obligation (19,870 ) — — — (1,282 ) (18,588 ) Total Level 2 (4,299 ) 1,282 14,289 — (1,282 ) (18,588 ) Total $ 19,508 $ 1,282 $ 14,289 $ 23,807 $ (1,282 ) $ (18,588 ) Balance Sheet Classification Fair Value Other Current Assets Assets Designated for Retirement and Pension Plans Investments Other Current Liabilities Retirement and Pension Plans Balance at December 31, 2018 Level 1 (1) : U.S. non-qualified deferred compensation plan $ 19,442 $ — $ — $ 19,442 $ — $ — Level 2 (2) : Retirement and pension plan assets 16,384 1,349 15,035 — — — Pension benefit obligation (20,908 ) — — — (1,349 ) (19,559 ) Total Level 2 (4,524 ) 1,349 15,035 — (1,349 ) (19,559 ) Total $ 14,918 $ 1,349 $ 15,035 $ 19,442 $ (1,349 ) $ (19,559 ) (1) Level 1 – Quoted prices in active markets for identical assets and liabilities. (2) Level 2 – Quoted prices in active markets for similar assets and liabilities, or other inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument.
Cash and Available-for-sale Securities by Significant Investment Category [Table Text Block]	The Company's cash, cash equivalents, and marketable securities by significant investment category are as follows: Fair Value Balance Sheet Classification Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and Cash Equivalents Marketable Securities Balance at September 30, 2019 Cash $ 114,467 $ — Level 1 (1) : Money market funds 15,595 — — 15,595 15,595 — U.S. Treasury securities 82,386 12 — 82,398 46,310 36,088 Total Level 1 97,981 12 — 97,993 61,905 36,088 Level 2 (2) : Commercial paper 6,478 — — 6,478 — 6,478 Total $ 104,459 $ 12 $ — $ 104,471 $ 176,372 $ 42,566 Fair Value Balance Sheet Classification Amortized Cost Unrealized Gains Unrealized Losses Fair Value Cash and Cash Equivalents Marketable Securities Balance at December 31, 2018 Cash $ 279,829 $ — Level 1 (1) : Money market funds 77 — — 77 77 — Total $ 77 $ — $ — $ 77 $ 279,906 $ — (1) Level 1 – Quoted prices in active markets for identical assets and liabilities. (2) Level 2 – Quoted prices in active markets for similar assets and liabilities, or other inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument.

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill by Segment [Line Items]
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	The Company's estimated future amortization expense related to intangible assets as of September 30, 2019 , for the years ended December 31 is as follows: Estimated Future Amortization 2019 $ 287 2020 998 2021 833 2022 723 2023 632 Thereafter 955 Total $ 4,428
Changes in Carrying Amount of Goodwill by Segment	Changes in the carrying amount of goodwill by segment for the nine months ended September 30, 2019 , are as follows: Executive Search Americas Europe Asia Pacific Heidrick Consulting Total Gross goodwill at December 31, 2018 $ 88,410 $ 24,924 $ 8,758 $ 36,257 $ 158,349 Accumulated impairment — — — (36,257 ) (36,257 ) Net goodwill at December 31, 2018 88,410 24,924 8,758 — 122,092 2GET acquisition 7,504 — — — 7,504 Foreign currency translation 98 (975 ) (433 ) — (1,310 ) Net goodwill at September 30, 2019 $ 96,012 $ 23,949 $ 8,325 $ — $ 128,286
Summary of Other Intangible Assets Net by Segment	The Company’s other intangible assets, net by segment, are as follows: September 30, December 31, Executive Search Americas $ 2,951 $ 52 Europe 1,412 2,086 Asia Pacific 65 78 Total Executive Search 4,428 2,216 Heidrick Consulting — — Total other intangible assets, net $ 4,428 $ 2,216
Carrying Amount of Amortizable Intangible Assets and Related Accumulated Amortization	The carrying amount of amortizable intangible assets and the related accumulated amortization are as follows: Weighted September 30, 2019 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Client relationships 6.2 $ 18,628 $ (14,200 ) $ 4,428 $ 15,910 $ (13,694 ) $ 2,216

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets Goodwill by Segment (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill by Segment [Line Items]
Goodwill by Segment [Table Text Block]	The Company's goodwill by segment is as follows: September 30, December 31, Executive Search Americas $ 96,012 $ 88,410 Europe 23,949 24,924 Asia Pacific 8,325 8,758 Total Executive Search 128,286 122,092 Heidrick Consulting 36,257 36,257 Goodwill, gross 164,543 158,349 Accumulated impairment (36,257 ) (36,257 ) Goodwill, net $ 128,286 $ 122,092

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets Goodwill, Carrying Amount (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill [Line Items]
Goodwill, Impaired, Accumulated Impairment Loss	Changes in the carrying amount of goodwill by segment for the nine months ended September 30, 2019 , are as follows: Executive Search Americas Europe Asia Pacific Heidrick Consulting Total Gross goodwill at December 31, 2018 $ 88,410 $ 24,924 $ 8,758 $ 36,257 $ 158,349 Accumulated impairment — — — (36,257 ) (36,257 ) Net goodwill at December 31, 2018 88,410 24,924 8,758 — 122,092 2GET acquisition 7,504 — — — 7,504 Foreign currency translation 98 (975 ) (433 ) — (1,310 ) Net goodwill at September 30, 2019 $ 96,012 $ 23,949 $ 8,325 $ — $ 128,286

Other Non-Current Liabilities (

Other Non-Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2019
Other Liabilities Disclosure [Abstract]
Components of Other Non-Current Liabilities	The components of other non-current liabilities are as follows: September 30, December 31, Premise related costs $ 2,557 $ 15,473 Accrued earnout payments 5,862 — Other 2,089 1,950 Total other non-current liabilities $ 10,508 $ 17,423

Other Current Assets and Non-cu

Other Current Assets and Non-current Liabilities Other Current Assets (Tables)	9 Months Ended
	Sep. 30, 2019
Other current assets [Line Items]
Schedule of Other Current Assets [Table Text Block]	The components of other current assets are as follows: September 30, December 31, Contract assets $ 22,776 $ 23,975 Other 5,190 5,623 Total other current assets $ 27,966 $ 29,598

Stock-based Compensation (Table

Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation, Phantom Shares Award Outstanding Activity [Table Text Block]	Phantom stock unit activity for the nine months ended September 30, 2019 is as follows: Number of Stock Units Outstanding on December 31, 2018 111,673 Granted 154,387 Vested and converted to common stock — Forfeited — Outstanding on September 30, 2019 266,060
Summary of Information with Respect to Stock-based Compensation	A summary of information with respect to stock-based compensation is as follows: Three Months Ended Nine Months Ended 2019 2018 2019 2018 Salaries and benefits (1) $ 3,294 $ 2,911 $ 7,941 $ 6,200 General and administrative expenses — — 460 563 Income tax benefit related to stock-based compensation included in net income 870 771 2,219 1,792
Restricted Stock Unit Activity	Restricted stock unit activity for the nine months ended September 30, 2019 is as follows: Number of Weighted- Outstanding on December 31, 2018 512,446 $ 28.83 Granted 270,488 33.55 Vested and converted to common stock (175,792 ) 24.19 Forfeited (3,453 ) 34.43 Outstanding on September 30, 2019 603,689 $ 32.27
Performance Stock Unit Activity	Performance stock unit activity for the nine months ended September 30, 2019 is as follows: Number of Stock Units Weighted- Outstanding on December 31, 2018 197,117 $ 27.58 Granted 64,701 37.62 Vested and converted to common stock (99,219 ) 25.04 Forfeited — — Outstanding on September 30, 2019 162,599 $ 33.13

Restructuring (Tables)

Restructuring (Tables)	9 Months Ended
	Sep. 30, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Activities Disclosure [Text Block]	Changes to the accrual for restructuring charges for the nine months ended September 30, 2019 , are as follows: Employee Related Other Total Outstanding on December 31, 2018 $ 1,269 $ 17 $ 1,286 Restructuring charges 4,130 — 4,130 Cash payments (1,554 ) — (1,554 ) Non cash write offs — (17 ) (17 ) Other 4 — 4 Exchange rate fluctuations (74 ) — (74 ) Outstanding on September 30, 2019 $ 3,775 $ — $ 3,775

Changes in Accumulated Other _2

Changes in Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Changes in Accumulated Other Comprehensive Income ("AOCI") by Component	The changes in Accumulated other comprehensive income (“AOCI”) by component for the nine months ended September 30, 2019 is summarized below: Available- Foreign Pension AOCI Balance at December 31, 2018 $ — $ 5,258 $ (1,196 ) $ 4,062 Other comprehensive income before classification, net of tax 12 (1,024 ) — (1,012 ) Net current period other comprehensive income 12 (1,024 ) — (1,012 ) Balance at September 30, 2019 $ 12 $ 4,234 $ (1,196 ) $ 3,050

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting Information [Line Items]
Revenue and Operating Income (Loss), by Segment	The revenue and operating income (loss) by segment are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Revenue Executive Search Americas $ 108,878 $ 106,504 $ 308,700 $ 295,499 Europe 34,827 37,452 103,244 110,419 Asia Pacific 22,784 28,095 71,394 78,460 Total Executive Search 166,489 172,051 483,338 484,378 Heidrick Consulting 15,685 15,537 43,552 46,340 Revenue before reimbursements (net revenue) 182,174 187,588 526,890 530,718 Reimbursements 4,344 4,753 14,075 13,970 Total revenue $ 186,518 $ 192,341 $ 540,965 $ 544,688 Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Operating income (loss) Executive Search Americas (1) $ 23,211 $ 23,341 $ 74,211 $ 69,988 Europe 466 904 3,788 6,453 Asia Pacific 2,421 6,414 10,642 13,608 Total Executive Search 26,098 30,659 88,641 90,049 Heidrick Consulting (3,150 ) (1,761 ) (12,770 ) (10,988 ) Total segment operating income 22,948 28,898 75,871 79,061 Global Operations Support (1) (8,476 ) (8,315 ) (26,655 ) (26,896 ) Total operating income $ 14,472 $ 20,583 $ 49,216 $ 52,165 (1) 2019 includes restructuring charges of $4.1 million in the Americas and less than $0.1 million in Global Operations Support.

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 176,372,000	$ 279,906,000	$ 164,216,000	$ 207,534,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	176,372,000	280,262,000	164,814,000	208,162,000
Other Current Assets [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash	0	108,000	598,000	526,000
Other Noncurrent Assets [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted Cash	$ 0	$ 248,000	$ 0	$ 102,000

Summary of Significant Accoun_6

Summary of Significant Accounting Policies Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Weighted Average Number of Shares Outstanding, Diluted	19,428			19,401			19,518	19,444
Earnings Per Share, Basic	$ 0.52			$ 0.87			$ 1.90	$ 2.02
Earnings Per Share, Diluted	$ 0.51			$ 0.85			$ 1.86	$ 1.96
Cash and Cash Equivalents, at Carrying Value	$ 176,372,000			$ 164,216,000			$ 176,372,000	$ 164,216,000	$ 279,906,000	$ 207,534,000
Net Income (Loss) Attributable to Parent	$ 9,947,000	$ 14,280,000	$ 12,087,000	$ 16,469,000	$ 11,463,000	$ 10,168,000	$ 36,314,000	$ 38,100,000
Weighted Average Number of Shares Outstanding, Basic	19,127			18,954			19,084	18,905
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 176,372,000			$ 164,814,000			$ 176,372,000	$ 164,814,000	280,262,000	208,162,000
Other Current Assets [Member]
Restricted Cash	0			598,000			0	598,000	108,000	526,000
Other Noncurrent Assets [Member]
Restricted Cash	$ 0			$ 0			$ 0	$ 0	$ 248,000	$ 102,000
Restricted Stock Units (RSUs) [Member]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	195			278			283	345
Performance Shares [Member]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	106			169			151	194

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Contract Assets and Liabilities [Line Items]
Deferred Revenue, Revenue Recognized	$ 33,800
Unbilled Contracts Receivable	9,090	$ 8,684
Increase (Decrease) in Unbilled Contracts Receivable	406
Contract with Customer, Asset, Net	13,686	15,291
Increase (Decrease) in Contract Assets	(1,605)
Contract Assets	22,776	23,975
Total Contract Asset Increase Decrease	(1,199)
Deferred Revenue, Current	40,434	$ 40,673
Increase (Decrease) in Contract Liabilities	(239)
Revenue Recognition, Multiple-deliverable Arrangements, Allocation to Specific Unit of Accounting, Effect of Changes, Selling Price	$ 17,800

Allowance for Doubtful Accoun_3

Allowance for Doubtful Accounts - Summary of Allowance for Doubtful Accounts (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Schedule of Allowance for Doubtful Accounts Receivable [Line Items]
Allowance for Doubtful Accounts Receivable	$ 4,387	$ 3,502
Allowance for Doubtful Accounts Receivable [Roll Forward]
Provision charged to income	3,058
Write-offs	(2,101)
Currency	$ (72)

Property and Equipment, Net - C

Property and Equipment, Net - Components of Company's Property and Equipment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Depreciation	$ 2,400	$ 2,700	$ 7,300	$ 8,300
Property and equipment, gross	90,523		90,523		$ 93,437
Accumulated depreciation	(61,167)		(61,167)		(59,566)
Property and equipment, net	29,356		29,356		33,871
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	45,839		45,839		48,455
Office Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	17,441		17,441		17,919
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 27,243		$ 27,243		$ 27,063

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 2.4	$ 2.7	$ 7.3	$ 8.3

Leases (Details)

Leases (Details)	Sep. 30, 2019
Minimum [Member] | Office Leases [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	1 year
Minimum [Member] | Equipment Leases [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	1 year
Maximum [Member] | Office Leases [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	7 years
Maximum [Member] | Equipment Leases [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	4 years 8 months

Leases Lease, Cost (Details)

Leases Lease, Cost (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lease, Cost [Abstract]
Operating Lease, Expense	$ 6,180	$ 18,660
Variable Lease, Cost	2,128	6,042
Lease, Cost	$ 8,308	$ 24,702

Leases Operating Lease, Supplem

Leases Operating Lease, Supplemental Cash Flow Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Operating Leases, Supplemental Cash Flow Information [Abstract]
Operating Lease, Payments	$ 26,879
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 11,385

Leases Lessee, Operating Lease,

Leases Lessee, Operating Lease, Liability, Maturity (Details) $ in Thousands	Sep. 30, 2019USD ($)
Lessee, Operating Lease, Liability, Maturity [Abstract]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 9,441
Operating Leases, Future Minimum Payments, Due in Four Years	22,097
Operating Leases, Future Minimum Payments, Due in Two Years	30,518
Operating Leases, Future Minimum Payments, Due in Three Years	25,662
Operating Leases, Future Minimum Payments, Due in Five Years	19,189
Operating Leases, Future Minimum Payments, Due Thereafter	13,258
Operating Leases, Future Minimum Payments Due	120,165
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(12,631)
Operating Lease, Liability	$ 107,534

Leases Operating Lease, Weighte

Leases Operating Lease, Weighted Averages (Details)	Sep. 30, 2019
Operating Lease Weighted Averages [Abstract]
Operating Lease, Weighted Average Remaining Lease Term	4 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent	3.97%

Acquisitions (Details)

Acquisitions (Details) - USD ($) $ in Millions	Sep. 24, 2019	Sep. 30, 2019
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 5
Business Combination, Consideration Transferred, Cash	4.1
Business Combination, Consideration Transferred, Other	$ 1.1
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low		$ 5
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High		15
Business Combination, Contingent Consideration, Liability		5.9
Finite-lived Intangible Assets Acquired		3
Goodwill		$ 7.5

Investments - Components of Com

Investments - Components of Company's Investments (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Cash [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 114,467	$ 279,829
Marketable Securities	0	0
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	15,595	77
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale	15,595	77
Cash and Cash Equivalents, at Carrying Value	15,595	77
Marketable Securities	0	$ 0
Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	82,386
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	12
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0
Debt Securities, Available-for-sale	82,398
Cash and Cash Equivalents, at Carrying Value	46,310
Marketable Securities	36,088
Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	6,478
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0
Debt Securities, Available-for-sale	6,478
Cash and Cash Equivalents, at Carrying Value	0
Marketable Securities	$ 6,478

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($)	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	$ 0	$ 0
Marketable Securities	42,566,000	0
Debt Securities, Available-for-sale, Amortized Cost	104,459,000	77,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	12,000
Debt Securities, Available-for-sale	104,471,000	77,000
Cash and Cash Equivalents, at Carrying Value	176,372,000	279,906,000	$ 164,216,000	$ 207,534,000
Long-term Investments	23,807,000	19,442,000
Aggregate cost basis for investments	16,500,000	14,600,000
Fair Value, Net Asset (Liability)	19,508,000	14,918,000
Fair Value, Inputs, Level 1 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0
Marketable Securities	36,088,000
Debt Securities, Available-for-sale, Amortized Cost	97,981,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	12,000
Debt Securities, Available-for-sale	97,993,000
Cash and Cash Equivalents, at Carrying Value	61,905,000
U.S. non-qualified deferred compensation plan assets	23,807,000	19,442,000
Fair Value, Inputs, Level 2 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Defined Benefit Plan, Plan Assets, Amount	15,571,000	16,384,000
Defined Benefit Plan, Benefit Obligation	(19,870,000)	(20,908,000)
Fair Value, Net Asset (Liability)	(4,299,000)	(4,524,000)
Other Current Assets [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fair Value, Net Asset (Liability)	1,282,000	1,349,000
Other Current Assets [Member] | Fair Value, Inputs, Level 1 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
U.S. non-qualified deferred compensation plan assets	0	0
Other Current Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,282,000	1,349,000
Defined Benefit Plan, Benefit Obligation	0	0
Fair Value, Net Asset (Liability)	1,282,000	1,349,000
Other Current Liabilities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fair Value, Net Asset (Liability)	(1,282,000)	(1,349,000)
Other Current Liabilities [Member] | Fair Value, Inputs, Level 1 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Available-for-sale Securities	0	0
Other Current Liabilities [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Defined Benefit Plan, Benefit Obligation	(1,282,000)	(1,349,000)
Fair Value, Net Asset (Liability)	(1,282,000)	(1,349,000)
Assets Designated for Retirement and Pension Plans [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fair Value, Net Asset (Liability)	14,289,000	15,035,000
Assets Designated for Retirement and Pension Plans [Member] | Fair Value, Inputs, Level 1 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
U.S. non-qualified deferred compensation plan assets	0	0
Assets Designated for Retirement and Pension Plans [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Defined Benefit Plan, Plan Assets, Amount	14,289,000	15,035,000
Defined Benefit Plan, Benefit Obligation	0	0
Fair Value, Net Asset (Liability)	14,289,000	15,035,000
Investments [Domain]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fair Value, Net Asset (Liability)	23,807,000	19,442,000
Investments [Domain] | Fair Value, Inputs, Level 1 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
U.S. non-qualified deferred compensation plan assets	23,807,000	19,442,000
Investments [Domain] | Fair Value, Inputs, Level 2 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Defined Benefit Plan, Benefit Obligation	0	0
Fair Value, Net Asset (Liability)	0	0
Other Pension Plan [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Fair Value, Net Asset (Liability)	(18,588,000)	(19,559,000)
Other Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Available-for-sale Securities	0	0
Other Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Defined Benefit Plan, Benefit Obligation	(18,588,000)	(19,559,000)
Fair Value, Net Asset (Liability)	$ (18,588,000)	$ (19,559,000)

Fair Value Measurements - Level

Fair Value Measurements - Levels of Inputs Used to Measure Fair Value of Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of assets	$ 19,508	$ 14,918
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets designated for retirement and pension plans	15,571	16,384
Defined Benefit Plan, Benefit Obligation	(19,870)	(20,908)
Total fair value of assets	$ (4,299)	$ (4,524)

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Beginning and Ending Balance of Level 3 Assets and Liabilities (Detail) - Fair Value, Inputs, Level 3 [Member] - Acquisition Earnout Accruals [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Fair Value, Asset and Liabilities Measured on Recurring and Nonrecurring Basis, Level 3 [Roll Forward]
Beginning balance, acquisition earnout accruals	$ (6,627)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Business Combination, Acquisition Earnout, Fair Value	(5,862)
Earnout Accretion Fair Value Disclosure	(495)
Earnout Payments Fair Value Disclosure	3,009
Foreign currency translation	209
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Business Combination, Acquisition Earnout Adjustment, Fair Value	(1,135)
Ending balance, acquisition earnout accruals	$ (10,901)

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill, Amrop Acquisition	$ 7,504,000
Goodwill, Gross	164,543,000	$ 158,349,000
Goodwill, Impaired, Accumulated Impairment Loss	(36,257,000)	(36,257,000)
Goodwill [Roll Forward]
Foreign currency translation	(1,310,000)
Goodwill	128,286,000	122,092,000
Executive Search [Member]
Goodwill [Line Items]
Goodwill, Gross	128,286,000	122,092,000
Executive Search [Member] | Americas [Member]
Goodwill [Line Items]
Goodwill, Amrop Acquisition	7,504,000
Goodwill, Gross	96,012,000	88,410,000
Goodwill, Impaired, Accumulated Impairment Loss		0
Goodwill [Roll Forward]
Foreign currency translation	98,000
Goodwill	96,012,000	88,410,000
Executive Search [Member] | Europe [Member]
Goodwill [Line Items]
Goodwill, Amrop Acquisition	0
Goodwill, Gross	23,949,000	24,924,000
Goodwill, Impaired, Accumulated Impairment Loss		0
Goodwill [Roll Forward]
Foreign currency translation	(975,000)
Goodwill	23,949,000	24,924,000
Executive Search [Member] | Asia Pacific [Member]
Goodwill [Line Items]
Goodwill, Amrop Acquisition	0
Goodwill, Gross	8,325,000	8,758,000
Goodwill, Impaired, Accumulated Impairment Loss		0
Goodwill [Roll Forward]
Foreign currency translation	(433,000)
Goodwill	8,325,000	8,758,000
Heidrick Consulting [Domain]
Goodwill [Line Items]
Goodwill, Amrop Acquisition	0
Goodwill, Gross	36,257,000	36,257,000
Goodwill, Impaired, Accumulated Impairment Loss		36,257,000
Goodwill [Roll Forward]
Foreign currency translation	0
Goodwill	$ 0	$ 0

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Summary of Other Intangible Assets Net by Segment (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 3,000,000
Net Carrying Amount	4,428,000	$ 2,216,000
Goodwill	128,286,000	122,092,000
Executive Search [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	4,428,000	2,216,000
Executive Search [Member] | Americas [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	2,951,000	52,000
Goodwill	96,012,000	88,410,000
Executive Search [Member] | Europe [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	1,412,000	2,086,000
Goodwill	23,949,000	24,924,000
Executive Search [Member] | Asia Pacific [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	65,000	78,000
Goodwill	8,325,000	8,758,000
Heidrick Consulting [Domain]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	0	0
Goodwill	$ 0	$ 0

Goodwill and Other Intangible_7

Goodwill and Other Intangible Assets - Carrying Amount of Amortizable Intangible Assets and Related Accumulated Amortization (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 200,000	$ 400,000	$ 700,000	$ 1,200,000
Net Carrying Amount	4,428,000		$ 4,428,000		$ 2,216,000
Client Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Years)			6 years 2 months
Gross Carrying Amount	18,628,000		$ 18,628,000		15,910,000
Accumulated Amortization	14,200,000		14,200,000		13,694,000
Net Carrying Amount	$ 4,428,000		$ 4,428,000		$ 2,216,000

Goodwill and Other Intangible_8

Goodwill and Other Intangible Assets - Intangible Assets - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	$ 287,000
Finite-lived Intangible Assets Acquired	3,000,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	998,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	833,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	723,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five	632,000
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	955,000
Finite-Lived Intangible Assets, Net	$ 4,428,000	$ 2,216,000

Goodwill and Other Intangible_9

Goodwill and Other Intangible Assets Goodwill by Segment (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill, Gross	$ 164,543,000	$ 158,349,000
Goodwill, Impaired, Accumulated Impairment Loss	(36,257,000)	(36,257,000)
Goodwill	128,286,000	122,092,000
Executive Search [Member]
Goodwill [Line Items]
Goodwill, Gross	128,286,000	122,092,000
Heidrick Consulting [Domain]
Goodwill [Line Items]
Goodwill, Gross	36,257,000	36,257,000
Goodwill, Impaired, Accumulated Impairment Loss		36,257,000
Goodwill	0	0
Americas [Member] | Executive Search [Member]
Goodwill [Line Items]
Goodwill, Gross	96,012,000	88,410,000
Goodwill, Impaired, Accumulated Impairment Loss		0
Goodwill	96,012,000	88,410,000
Europe [Member] | Executive Search [Member]
Goodwill [Line Items]
Goodwill, Gross	23,949,000	24,924,000
Goodwill, Impaired, Accumulated Impairment Loss		0
Goodwill	23,949,000	24,924,000
Asia Pacific [Member] | Executive Search [Member]
Goodwill [Line Items]
Goodwill, Gross	8,325,000	8,758,000
Goodwill, Impaired, Accumulated Impairment Loss		0
Goodwill	$ 8,325,000	$ 8,758,000

Other Non-Current Liabilities -

Other Non-Current Liabilities - Components of Other Non-Current Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Other Non-Current Liabilities - Components of Other Non-current Liabilities [Line Items]
Premise related costs	$ 2,557	$ 15,473
Accrued earnout payments	5,862	0
Other	2,089	1,950
Total other non-current liabilities	$ 10,508	$ 17,423

Other Current Assets and Non-_2

Other Current Assets and Non-current Liabilities Other Current Assets - Components of Other Current Assets (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Other Current Assets - Components of Other Current Assets [Line Items]
Unbilled Receivables, Current	$ 22,776,000	$ 23,975,000
Other Assets, Miscellaneous, Current	5,190,000	5,623,000
Other Assets, Current	$ 27,966,000	$ 29,598,000

Line of Credit - Additional Inf

Line of Credit - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	9 Months Ended
	Mar. 31, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Jun. 30, 2015
Line of Credit Facility [Line Items]
Proceeds from Lines of Credit			$ 0	$ 20,000
Long-term debt, gross			0		$ 0
Repayments of Lines of Credit			0	$ (20,000)
2018 Credit Agreement [Member]
Line of Credit Facility [Line Items]
Senior unsecured revolving line of credit aggregate commitment			175,000
Sublimit for letters of credit			25,000
Line of credit facility expansion feature			75,000
Swingline Loan Sublimit			10,000
Payments of Debt Issuance Costs			$ 1,000
Senior Unsecured Revolving Line Of Credit Member [Member]
Line of Credit Facility [Line Items]
Senior unsecured revolving line of credit aggregate commitment						$ 100,000
Sublimit for letters of credit						25,000
Line of credit facility expansion feature						$ 50,000
Proceeds from Lines of Credit	$ 20,000
Repayments of Long-term Debt	$ 8,000	$ 12,000

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Detail) - USD ($)	May 24, 2018	May 22, 2014	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense			$ 800,000	$ 400,000	$ 1,200,000	$ 400,000
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense			$ 870,000	771	$ 2,219,000	1,792
Phantom Share Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			266,060		266,060		111,673
Pre-tax unrecognized compensation expense			$ 5,200,000		$ 5,200,000
Expected time to be recognized					3 years 7 months
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period					154,387
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period					0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period					0
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			603,689		603,689		512,446
Pre-tax unrecognized compensation expense			$ 11,400,000		$ 11,400,000
Expected time to be recognized					2 years 9 months
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period					270,488
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period					175,792
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period					3,453
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			162,599		162,599		197,117
Pre-tax unrecognized compensation expense			$ 3,400,000		$ 3,400,000
Expected time to be recognized					2 years 1 month
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period					64,701
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period					99,219
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period					0
Performance Stock Units [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance stock units vesting period					3 years
Performance Stock Units [Member] | Minimum [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance stock units, variation percentage					0.00%
Performance Stock Units [Member] | Maximum [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance stock units, variation percentage					200.00%
2012 Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized or reserved for issuance with respect to awards granted								1,300,000
Increase in number of shares of common stock reserved for issuance	850,000	700,000
Number of stock awards issued under 2012 Program					2,495,928
Shares available for future awards			1,032,494		1,032,494
Number of forfeited awards under 2012 Program					678,422
Labor and Related Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost			$ 3,294,000	2,911	$ 7,941,000	6,200
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost			$ 0	$ 0	$ 460,000	$ 563

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Information with Respect to Stock-Based Compensation (Detail) - USD ($)	May 24, 2018	May 22, 2014	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
General and administrative expenses			$ 800,000	$ 400,000	$ 1,200,000	$ 400,000
Income tax benefit related to stock-based compensation included in net income			870,000	771	2,219,000	1,792
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Salaries and employee benefits (1)			$ 0	$ 0	$ 460,000	$ 563
Two Thousand Twelve Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized							1,300,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	850,000	700,000
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period					2,495,928
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant			1,032,494		1,032,494
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares					678,422

Stock-based Compensation - Rest

Stock-based Compensation - Restricted Stock Unit Activity (Detail) - Restricted Stock Units [Member] $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $	$ 11.4
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of stock units, beginning balance | shares	512,446
Number of stock units, granted | shares	270,488
Number of stock units, vested and converted to common stock | shares	(175,792)
Number of stock units, forfeited | shares	(3,453)
Number of stock units, ending balance | shares	603,689
Weighted-average grant-date fair value, beginning balance | $ / shares	$ 28.83
Weighted-average grant-date fair value, granted | $ / shares	33.55
Weighted-average grant-date fair value, vested and converted to common stock | $ / shares	24.19
Weighted-average grant-date fair value, forfeited | $ / shares	34.43
Weighted-average grant-date fair value, ending balance | $ / shares	$ 32.27
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 9 months

Stock-based Compensation - Perf

Stock-based Compensation - Performance Stock Unit Activity (Detail) - Performance Stock Units [Member] $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $	$ 3.4
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of stock units, beginning balance | shares	197,117
Number of stock units, granted | shares	64,701
Number of stock units, vested and converted to common stock | shares	(99,219)
Number of stock units, forfeited | shares	0
Number of stock units, ending balance | shares	162,599
Weighted-average grant-date fair value, beginning balance | $ / shares	$ 27.58
Weighted-average grant-date fair value, granted | $ / shares	37.62
Weighted-average grant-date fair value, vested and converted to common stock | $ / shares	25.04
Weighted-average grant-date fair value, forfeited | $ / shares	0
Weighted-average grant-date fair value, ending balance | $ / shares	$ 33.13
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 1 month
Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Minimum [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	0.00%
Maximum [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	200.00%

Stock-based Compensation Stock-

Stock-based Compensation Stock-based Compensation - Phantom Unit Activity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 0.8	$ 0.4	$ 1.2	$ 0.4
Phantom Share Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 5.2		$ 5.2
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	266,060		266,060		111,673
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			154,387
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period			0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period			0
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			3 years 7 months

Restructuring (Details)

Restructuring (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2017	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 3,775		$ 1,286
Restructuring Charges	4,130	$ 15,700
Payments for Restructuring	(1,554)
Restructuring Charges, Non-cash Write-offs	17
Other Restructuring Costs	(4)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	(74)
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	3,775		1,269
Restructuring Charges	4,130
Payments for Restructuring	(1,554)
Restructuring Charges, Non-cash Write-offs	0
Other Restructuring Costs	(4)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	(74)
Other Professional and Consulting Fees [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0		$ 17
Restructuring Charges	0
Payments for Restructuring	0
Restructuring Charges, Non-cash Write-offs	17
Other Restructuring Costs	0
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	0
Corporate, Non-Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	100
Americas Segment [Member] | Operating Segments [Member] | Executive Search [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 4,100

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Results of Operations, Income before Income Taxes [Abstract]
Income before income taxes	$ 14,827	$ 23,187	$ 53,142	$ 54,510
Provision for income taxes	$ 4,880	$ 6,718	$ 16,828	$ 16,410
Effective Income Tax Rate Reconciliation, Percent	32.90%	29.00%	31.70%	30.10%
Minimum [Member]
Results of Operations, Income before Income Taxes [Abstract]
Forecasted Annual Effective Tax Rate			31.00%
Maximum [Member]
Results of Operations, Income before Income Taxes [Abstract]
Forecasted Annual Effective Tax Rate			34.00%

Changes in Accumulated Other _3

Changes in Accumulated Other Comprehensive Income - Changes in Accumulated Other Comprehensive Income ("AOCI") by Component (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 3,050						$ 3,050		$ 4,062
Increase (Decrease) in Stockholders' Equity [Roll Forward]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification						$ 8,954
Net current period other comprehensive income	(1,337)	$ 5	$ 320	$ (881)	$ (3,816)	1,590	(1,012)	$ (3,107)
Stockholders' equity attributable to parent	296,635	288,449	273,419	253,833	237,865	230,489	296,635	253,833	267,156	$ 212,705
Available-for-Sale Securities Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	12						12		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income before classification, net of tax							12
Net current period other comprehensive income							12
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	4,234						4,234		5,258
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income before classification, net of tax							(1,024)
Net current period other comprehensive income							(1,024)
Pension Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(1,196)						(1,196)		(1,196)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income before classification, net of tax							0
Net current period other comprehensive income							0
Accumulated Other Comprehensive Income [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income before classification, net of tax							(1,012)
Net current period other comprehensive income	(1,337)	5	320	(881)	(3,816)	1,590	(1,012)
Stockholders' equity attributable to parent	$ 3,050	$ 4,387	$ 4,382	$ 4,119	$ 5,000	8,816	$ 3,050	$ 4,119	$ 4,062	$ 13,315
Accounting Standards Update 2016-01 [Member] | Accumulated Other Comprehensive Income [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification						$ (6,089)

Segment Information - Revenue a

Segment Information - Revenue and Operating Income (Loss), by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Restructuring Charges			$ 4,130		$ 15,700
Revenue, Net of Reimbursements	$ 182,174	$ 187,588	526,890	$ 530,718
Goodwill and Intangible Asset Impairment	4,130	0	4,130	0
Revenue
Reimbursements Revenue	4,344	4,753	14,075	13,970
Total revenue	186,518	192,341	540,965	544,688
Operating income (loss)
Operating (loss) income	14,472	20,583	49,216	52,165
Operating Segments [Member]
Operating income (loss)
Operating (loss) income	22,948	28,898	75,871	79,061
Global Operations Support [Member]
Segment Reporting Information [Line Items]
Restructuring Charges			100
Operating income (loss)
Operating (loss) income	(8,476)	(8,315)	(26,655)	(26,896)
Executive Search [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, Net of Reimbursements	166,489	172,051	483,338	484,378
Operating income (loss)
Operating (loss) income	26,098	30,659	88,641	90,049
Heidrick Consulting [Domain] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, Net of Reimbursements	15,685	15,537	43,552	46,340
Operating income (loss)
Operating (loss) income	(3,150)	(1,761)	(12,770)	(10,988)
Executive Search and Leadership Consulting Americas Segment [Member] | Executive Search [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Restructuring Charges			4,100
Revenue, Net of Reimbursements	108,878	106,504	308,700	295,499
Operating income (loss)
Operating (loss) income	23,211	23,341	74,211	69,988
Executive Search and Leadership Consulting Europe Segment [Member] | Executive Search [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, Net of Reimbursements	34,827	37,452	103,244	110,419
Operating income (loss)
Operating (loss) income	466	904	3,788	6,453
Executive Search and Leadership Consulting Asia Pacific Segment [Member] | Executive Search [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, Net of Reimbursements	22,784	28,095	71,394	78,460
Operating income (loss)
Operating (loss) income	$ 2,421	$ 6,414	$ 10,642	$ 13,608

Guarantees - Additional Informa

Guarantees - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Guarantees [Abstract]
Maximum undiscounted payments under outstanding guarantees	$ 2.6
Extend termination dates of the leases	extend through 2024