Heidrick & Struggles International (HSII) 10-K 26 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 22, 2019	Jun. 30, 2018
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	HSII
Entity Registrant Name	HEIDRICK & STRUGGLES INTERNATIONAL INC
Entity Central Index Key	1,066,605
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		18,984,344
Entity Public Float			$ 568,550,686

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 279,906	$ 207,534
Accounts receivable, net	114,977	98,700
Prepaid expenses	22,766	22,003
Other current assets	29,598	11,620
Income taxes recoverable	3,620	3,933
Total current assets	450,867	343,790
Non-current assets:
Property and equipment, net	33,871	39,514
Assets designated for retirement and pension plans	15,035	17,130
Investments	19,442	21,319
Other non-current assets	22,276	8,999
Goodwill	122,092	118,892
Other intangible assets, net	2,216	2,158
Deferred income taxes	34,830	35,402
Total non-current assets	249,762	243,414
Total assets	700,629	587,204
Current liabilities:
Accounts payable	9,166	9,824
Accrued salaries and employee benefits	227,653	177,426
Deferred revenue, net	40,673	31,272
Other current liabilities	33,219	40,346
Income taxes payable	8,240	6,924
Total current liabilities	318,951	265,792
Non-current liabilities:
Employee-related Liabilities, Non-current	57,234	40,308
Retirement and pension plans	39,865	44,802
Other non-current liabilities	17,423	23,597
Total non-current liabilities	114,522	108,707
Total liabilities	433,473	374,499
Commitments and contingencies (Note 20)
Stockholders’ equity:
Preferred stock, $0.01 par value, 10,000,000 shares authorized, no shares issued at December 31, 2018 and December 31, 2017	0	0
Common stock, $0.01 par value, 100,000,000 shares authorized, 19,585,777 shares issued, 18,954,275 and 18,781,433 shares outstanding at December 31, 2018 and December 31, 2017, respectively	196	196
Treasury stock at cost, 631,502 and 804,344 shares at December 31, 2018 and December 31, 2017, respectively	(20,298)	(26,096)
Additional paid in capital	227,147	226,006
Retained earnings (deficit)	56,049	(716)
Accumulated other comprehensive income	4,062	13,315
Total stockholders’ equity	267,156	212,705
Total liabilities and stockholders’ equity	$ 700,629	$ 587,204

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars 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 dollars 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	18,954,275	18,781,433
Treasury stock, shares	631,502	804,344

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue:
Revenue before reimbursements (net revenue)	$ 716,023	$ 621,400	$ 582,390
Reimbursements	19,632	18,656	18,516
Total revenue	735,655	640,056	600,906
Operating expenses:
Salaries and employee benefits	506,349	434,219	400,070
General and administrative expenses	140,817	147,316	147,087
Goodwill and Intangible Asset Impairment	0	50,722	0
Restructuring Charges	0	15,666	0
Impairment charges	19,632	18,656	18,516
Total operating expenses	666,798	666,579	565,673
Operating income (loss)	68,857	(26,523)	35,233
Non-operating income (expense):
Interest, net	1,141	385	244
Other, net	494	(3,280)	2,289
Net non-operating income (expense)	1,635	(2,895)	2,533
Income (loss) before income taxes	70,492	(29,418)	37,766
Provision for income taxes	21,197	19,217	22,353
Net income (loss)	49,295	(48,635)	15,413
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	(3,885)	6,853	(6,271)
Net unrealized gain (loss) on available-for-sale investments	0	2,660	1,035
Pension gain (loss) adjustment	721	480	(701)
Other comprehensive income (loss), net of tax	(3,164)	(9,993)	5,937
Comprehensive income (loss)	$ 46,131	$ (38,642)	$ 9,476
Basic weighted average common shares outstanding (in shares)	18,917	18,735	18,540
Diluted weighted average common shares outstanding (in shares)	19,532	18,735	19,038
Weighted Average Number Diluted Shares Outstanding Adjustment	615	0	498
Basic net income per common share (in dollars per share)	$ 2.61	$ (2.60)	$ 0.83
Diluted net income per common share (in dollars per share)	2.52	(2.60)	0.81
Cash dividends paid per share (in dollars per share)	$ 0.52	$ 0.52	$ 0.52

Consolidated Statements of Chan

Consolidated Statements of Changes In Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Beginning Balance, shares at Dec. 31, 2015		19,586	1,206
Beginning Balance at Dec. 31, 2015	$ 254,802	$ 196	$ (39,583)	$ 232,358	$ 52,572	$ 9,259
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	15,413				15,413
Other comprehensive loss, net of tax	5,937					5,937
Treasury and common stock transactions:
Stock-based compensation	6,393			6,393
Vesting of equity, net of tax withholdings (in shares)			(167)
Vesting of equity, net of tax withholdings	(2,688)		$ (5,636)	(8,324)
Re-issuance of treasury stock (in shares)			(31)
Re-issuance of treasury stock	562		$ 1,032	470
Dividends	9,668				9,668
Dividend equivalents on restricted stock units	(287)				(287)
Ending Balance, shares at Dec. 31, 2016		19,586	1,008
Ending Balance at Dec. 31, 2016	258,590	$ 196	$ (32,915)	229,957	58,030	3,322
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(48,635)				(48,635)
Other comprehensive loss, net of tax	(9,993)					(9,993)
Treasury and common stock transactions:
Stock-based compensation	4,935			4,935
Vesting of equity, net of tax withholdings (in shares)			(188)
Vesting of equity, net of tax withholdings	(2,405)		$ (6,311)	(8,716)
Re-issuance of treasury stock (in shares)			(15)
Re-issuance of treasury stock	338		$ 508	170
Dividends	9,762				9,762
Dividend equivalents on restricted stock units	(349)				(349)
Ending Balance, shares at Dec. 31, 2017		19,586	805
Ending Balance at Dec. 31, 2017	212,705	$ 196	$ (26,096)	226,006	(716)	13,315
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	49,295				49,295
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 Updates 2014-09 and 2016-01 [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 loss, net of tax	(3,164)					(3,164)
Treasury and common stock transactions:
Stock-based compensation	8,947			8,947
Vesting of equity, net of tax withholdings (in shares)			(167)
Vesting of equity, net of tax withholdings	(2,233)		$ (5,604)	(7,837)
Re-issuance of treasury stock (in shares)			(6)
Re-issuance of treasury stock	225		$ 194	(31)
Dividends	7,389				7,389
Dividend equivalents on restricted stock units	(184)				(184)
Ending Balance, shares at Dec. 31, 2018		19,586	632
Ending Balance at Dec. 31, 2018	$ 267,156	$ 196	$ (20,298)	$ 227,147	$ 56,049	$ 4,062

Consolidated Statements of Ch_2

Consolidated Statements of Changes In Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash dividends per share (in dollars per share)	$ 0.52	$ 0.52	$ 0.52
Retained Earnings [Member]
Cash dividends per share (in dollars per share)	$ 0.52	$ 0.52	$ 0.52

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows - operating activities:
Net income (loss)	$ 49,295	$ (48,635)	$ 15,413
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	12,522	14,774	16,433
Deferred income taxes	(3,496)	(1,690)	2,394
Stock-based compensation expense	8,947	4,935	6,393
Accretion expense related to earnout payments	1,285	1,038	635
Cash paid for restructuring charges	0	(50,722)	0
Changes in assets and liabilities, net of effects of acquisitions:
Accounts receivables	16,759	1,882	14,425
Accounts payable	(526)	1,474	941
Accrued expenses	71,526	18,330	(3,808)
Deferred revenue	(1,899)	2,010	(1,672)
Income taxes (payable) recoverable, net	757	3,381	1,184
Retirement and pension plan assets and liabilities	(1,492)	3,065	4,215
Prepaid expenses	893	(797)	2,330
Other assets and liabilities, net	4,748	(5,626)	3,449
Changes in Restructuring Accrual	(11,617)		0
Net cash provided by operating activities	102,902	66,970	21,924
Cash flows - investing activities:
Acquisition of business, net of cash acquired	(3,083)	(364)	(27,722)
Capital expenditures	(5,960)	(14,022)	(5,351)
Purchases of available for sale investments	(2,201)	(2,269)	(2,475)
Proceeds from sale of available for sale investments	2,995	1,404	535
Net cash used in investing activities	(8,249)	(15,251)	(35,013)
Cash flows - financing activities:
Proceeds from Lines of Credit	20,000	40,000	0
Repayments of Lines of Credit	(20,000)	(40,000)	0
Debt issuance costs	(981)	0	0
Cash dividends paid	(10,181)	(10,111)	(9,955)
Payment of employee tax withholdings on equity transactions	(2,234)	(2,392)	(2,676)
Acquisition earnout payments	(3,592)	(4,557)	(4,562)
Net cash used in financing activities	(16,988)	(17,060)	(17,193)
Effect of exchange rates fluctuations on cash, cash equivalents and restricted cash	(5,565)	7,933	(2,365)
Net increase (decrease) in cash, cash equivalents and restricted cash	72,100	42,592	(32,647)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	280,262	208,162	165,570
Cash, cash equivalents and restricted cash at end of period	279,906	207,534	165,011
Cash paid for
Income taxes	22,616	14,814	16,817
Interest	$ 67	$ 193	$ 41

Basis of Presentation

Basis of Presentation	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Heidrick & Struggles International, Inc. and subsidiaries (the “Company”) is engaged in providing executive search and consulting services to clients on a retained basis. The Company operates in the Americas, Europe and Asia Pacific regions. The consolidated financial statements include Heidrick & Struggles International, Inc. and its wholly-owned subsidiaries and have been prepared using accounting principles generally accepted in the United States of America (“GAAP”). The preparation of these financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses. Significant items subject to estimates and assumptions include revenue recognition, allowances for deferred tax assets and liabilities, and 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Cash and Cash Equivalents The Company considers all highly liquid instruments with an original maturity of three months or less to be cash equivalents. Concentration of Risk The Company is potentially exposed to concentrations of risk associated with its accounts receivable. However, this risk is limited due to the Company’s large number of clients and their dispersion across many different industries and geographies. At December 31, 2018 and 2017, the Company had no significant concentrations of risk. Accounts Receivable The Company’s accounts receivable consist of trade receivables. The allowance for doubtful accounts is developed based upon several factors including the age of the Company’s accounts receivable, historical write-off experience and specific account analysis. These factors may change over time, impacting the allowance level. Fair Value of Financial Instruments Cash equivalents are stated at cost, which approximates fair value. The carrying value for receivables from clients, accounts payable, deferred revenue and other accrued liabilities reasonably approximate fair value due to the nature of the financial instruments and the short term nature of the items. Property and Equipment Property and equipment are stated at cost. Depreciation is computed using the straight-line method over the estimated useful life of the asset or, for leasehold improvements, the shorter of the lease term or the estimated useful life of the asset, as follows: Office furniture, fixtures and equipment 5–10 years Computer equipment and software 3–7 years Leasehold improvements are depreciated over the lesser of the lease term or life of the asset improvement, which typically range from three to ten years. Depreciation is calculated for tax purposes using accelerated methods, where applicable. Long-lived Assets The Company reviews its long-lived assets, including property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge, equal to the amount by which the carrying amount of the asset exceeds the fair value of the asset, is recognized. Investments The Company’s investments consist primarily of available-for-sale investments within the U.S. non-qualified deferred compensation plan (the “Plan”). Available-for-sale investments are reported at fair value with changes in unrealized gains (losses) and realized gains (losses), resulting from an employee’s termination from the Plan, recorded as a non-operating expense in Other, net in the Consolidated Statements of Comprehensive Income (Loss). Goodwill and Other Intangible Assets Goodwill represents the difference between the purchase price of acquired companies and the related fair value of the net assets acquired, which is accounted for by the acquisition method of accounting. Other intangible assets include client relationships and employee non-compete agreements. The Company performs assessments of the carrying value of goodwill at least annually and of its goodwill and other intangible assets whenever events occur or circumstances indicate that a carrying amount of these assets may not be recoverable. These circumstances include a significant change in business climate, attrition of key personnel, changes in financial condition or results of operations, a prolonged decline in the Company’s stock price and market capitalization, competition, and other factors. The goodwill impairment test compares the fair value of a reporting unit to its carrying amount, including goodwill. The Company operates four reporting units: Americas, Europe (which includes Africa), Asia Pacific (which includes the Middle East) and Heidrick Consulting. The goodwill impairment test is completed by comparing the fair value of a reporting unit with its carrying amount. The fair value of each of the Company’s reporting units is determined using a discounted cash flow methodology. An impairment charge is recognized for the amount by which the carrying value of the reporting unit exceeds its fair value; however, the loss recognized is not to exceed the total amount of goodwill allocated to that reporting unit. The other intangible asset impairment review compares the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge, equal to the amount by which the carrying amount of the asset exceeds the fair value, is recognized. Other intangible assets acquired are amortized either using the straight-line method over their estimated useful lives or based on the projected cash flow associated with the respective intangible assets. Restructuring Charges The Company accounts for restructuring charges by recognizing a liability at fair value when the costs are incurred. Revenue Recognition As a result of the adoption of ASU No. 2014-09, Revenue from Contracts with Customers, the Company's accounting policy for revenue recognition has been updated. See Note 3, Revenue . Reimbursements The Company incurs certain out-of-pocket expenses that are reimbursed by its clients, which are accounted for as revenue and expense in its Consolidated Statements of Comprehensive Income (Loss). Salaries and Employee Benefits Salaries and employee benefits consist of compensation and benefits paid to consultants, executive officers, and administrative and support personnel, of which the most significant elements are salaries and annual performance-related bonuses. Other items in this category are expenses related to sign-on bonuses, forgivable employee loans and minimum guaranteed bonuses (often incurred in connection with the hiring of new consultants), restricted stock unit and performance share unit amortization, payroll taxes, profit sharing and retirement benefits, and employee insurance benefits. Salaries and employee benefits are recognized on an accrual basis. Certain sign-on bonuses, retention awards, and minimum guaranteed compensation are capitalized and amortized in accordance with the terms of the respective agreements. A portion of the Company’s consultants’ and management cash bonuses are deferred and paid over a three -year vesting period. The portion of the bonus is approximately 15% depending on the employee’s level or position. The compensation expense related to the amounts being deferred is recognized on a graded vesting attribution method over the requisite service period. This service period begins on January 1 of the respective fiscal year and continues through the deferral date, which coincides with the Company’s bonus payments in the first quarter of the following year and for an additional three -year vesting period. The deferrals are recorded in Accrued salaries and employee benefits within both Current liabilities and Non-current liabilities in the Consolidated Balance Sheets. Income Taxes Deferred tax assets and liabilities are determined based on the differences between the financial statement and tax basis of assets and liabilities, applying enacted statutory tax rates in effect for the year in which the tax differences are expected to reverse. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment. Reclassifications Certain prior year amounts have been recast as a result of the change in the Company's operating segments and adoption of ASU No. 2016-18, Statement of Cash Flows: Restricted Cash. The reclassifications had no impact on net income, net cash flows or stockholders' equity. Earnings per Common Share Basic earnings per common share is computed by dividing net income by weighted average common shares outstanding for the year. 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 (loss) per share: December 31, 2018 2017 2016 Net income (loss) $ 49,295 $ (48,635 ) $ 15,413 Weighted average shares outstanding: Basic 18,917 18,735 18,540 Effect of dilutive securities: Restricted stock units 406 — 347 Performance stock units 209 — 151 Diluted 19,532 18,735 19,038 Basic earnings (loss) per share $ 2.61 $ (2.60 ) $ 0.83 Diluted earnings (loss) per share $ 2.52 $ (2.60 ) $ 0.81 Weighted average restricted stock units and performance stock units outstanding that could be converted into approximately 327,000 and 80,000 common shares, respectively, for the year ended December 31, 2017, were not included in the computation of diluted earnings per share because the effects would be anti-dilutive. Translation of Foreign Currencies The Company generally designates the local currency for all its subsidiaries as the functional currency. The Company translates the assets and liabilities of its subsidiaries into U.S. dollars at the current rate of exchange prevailing at the balance sheet date. Revenue and expenses are translated at a monthly average exchange rate for the period. Translation adjustments are reported as a component of Accumulated other comprehensive income . Restricted Cash The Company has lease agreements and business licenses with terms that require the Company to restrict cash through the termination dates of the agreements, which extend through 2024. Current and non-current restricted cash is included in Other current assets and Other non-current assets , respectively, on the Consolidated Balance Sheet. 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 December 31, 2018 , 2017 and 2016 : December 31, 2018 2017 2016 Cash and cash equivalents $ 279,906 $ 207,534 $ 165,011 Restricted cash included within other current assets 108 526 139 Restricted cash included within other non-current assets 248 102 420 Total cash, cash equivalents and restricted cash $ 280,262 $ 208,162 $ 165,570 Recently Issued Financial Accounting Standards In February 2016, the Financial Accounting Standards Board ("FASB") issued ASU No. 2016-02, Leases, intended to improve financial reporting about leasing transactions. The guidance requires entities that lease assets to recognize on their balance sheets the assets and liabilities for the rights and obligations created by those leases and to disclose key information about the leasing arrangements. In July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842 (Leases), which provides narrow amendments to clarify how to apply certain aspects of the new lease standard, and ASU No. 2018-11, Targeted Improvements to Topic 842 (Leases), which provides an additional, optional transition method that allows entities to initially apply the requirements by recognizing a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. An entity that adopts this method must report comparative periods in accordance with current guidance (Topic 840). The guidance is effective for interim and annual periods beginning after December 15, 2018 with early adoption permitted. The Company will adopt the guidance on January 1, 2019 using the modified retrospective method without restatement of the prior periods. As such, prior periods will continue to be presented under the existing guidance in Topic 840. The Company is currently performing its evaluation of the guidance. The Company's lease portfolio is primarily comprised of office leases, which are currently classified as operating leases and will continue to be classified as operating leases under the new guidance. The adoption of the guidance will have a material impact on the Company's Consolidated Balance Sheets with respect to recording a right-of-use asset and lease liability for each of the Company's leases. The Company will utilize the available practical expedient to not separate the non-lease components from the lease components in its office leases. The Company is currently assessing the impact of utilizing the practical expedient, however,the use of the practical expedient will increase the total lease liability. The Company does not anticipate a significant change in expense recognition as it relates to the new guidance. Recently Adopted Financial Accounting Standards In 2018, the Company adopted ASU No. 2018-02, Income Statement - Reporting Comprehensive Income, 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. ASU 2018-02 is effective for interim and annual periods beginning after December 15, 2018, with early adoption permitted. The Company elected not to utilize the available option to reclassify stranded tax effects in accumulated other comprehensive income resulting from the Tax Cuts and Jobs Act to retained earnings. On January 1, 2018, the Company adopted ASU No. 2017-09, Compensation - Stock Compensation, Scope of Modification Accounting, which is intended to provide clarity and reduce diversity in practice, cost and complexity when implementing a change in the terms or conditions of a share-based payment award. ASU No. 2017-09 requires that an entity should account for the effects of a modification unless the fair value, vesting conditions and whether the award is classified as a liability instrument or an equity instrument remain unchanged in the modification. The adoption of this guidance did not have an impact on the Company's financial statements. The future impact of this accounting guidance will be dependent on future modification events including the number of awards modified. On January 1, 2018, the Company adopted ASU No. 2017-07, Compensation - Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost, which is intended to improve the consistency, transparency and usefulness of net benefit cost disclosures. ASU No. 2017-07 requires that an employer report the service cost component of net benefit cost in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. Additionally, the other components of net benefit costs are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations. The adoption of this guidance did not have an impact on the Company's financial statements. On January 1, 2018, the Company adopted ASU No. 2016-18, Statement of Cash Flows: Restricted Cash, which requires that the statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash should be included with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the statement of cash flows. The adoption of this guidance increased the Company's beginning and ending balances of cash, cash equivalents and restricted cash in the Condensed Consolidated Statement of Cash Flows by approximately $0.4 million and $0.6 million, respectively for the year ended December 31, 2018. Beginning and ending balances of cash, cash equivalents and restricted cash in the Condensed Consolidated Statement of Cash Flows increased by approximately $0.6 million and $0.6 million, respectively for the year ended December 31, 2017. Beginning and ending balances of cash, cash equivalents and restricted cash in the Condensed Consolidated Statement of Cash Flows increased by approximately $7.8 million and $0.6 million, respectively for the year ended December 31, 2016. On January 1, 2018, the Company adopted ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments, which is intended to reduce diversity in practice as to how certain cash receipts and cash payments should be presented and classified. The adoption of this guidance did not have a material impact on the Company's financial statements for the years ended December 31, 2018 and 2017. For the year ended December 31, 2016, the Company reclassified approximately $2.9 million of earnout payments from cash flows used in financing activities to cash flows provided by operating activities. The reclassified amount represents the amount of the earnout payement that is in excess of the earnout accrual established at the acquisition date. On January 1, 2018, the Company adopted ASU No. 2016-01, Financial Instruments: Recognition and Measurement of Financial Assets and Financial Liabilities, which addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments including the recognition of unrealized changes in fair value within net income. The adoption of this guidance resulted in a reclassification of accumulated unrealized gains of approximately $6.1 million from accumulated other comprehensive income to retained earnings. The impact of the adoption of this guidance on the Company's Condensed Consolidated Statement of Comprehensive Income for the year ended December 31, 2018, was not material. The comparative periods have not been restated and continue to be reported under the accounting standards in effect for those periods. On January 1, 2018, the Company adopted ASU No. 2014-09, Revenue from Contracts with Customers, using the modified retrospective method. The Company applied the guidance to all contracts that were not complete as of the adoption date. The guidance requires that an entity recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for these goods or services. The Company recognized the cumulative effect of initially applying the new guidance as an adjustment to the opening balance of retained earnings. The comparative periods have not been restated and continue to be reported under the accounting standards in effect for those periods. See Note 3, Revenue in the Notes to Consolidated Financial Statements. Impacts on Financial Statements of Recently Adopted Financial Accounting Standards The cumulative effect of the changes made to our Condensed Consolidated Balance Sheet as of January 1, 2018, as a result of the adoption of ASU No. 2014-09, Revenue from Contracts with Customers, and ASU No. 2016-01, Financial Instruments: Recognition and Measurement of Financial Assets Financial Liabilities was as follows: December 31, ASU 2014-09 Adjustments ASU 2016-01 Adjustments January 1, Current assets Other current assets $ 11,620 $ 14,689 $ — $ 26,309 Total current assets 343,790 14,689 — 358,479 Non-current assets Deferred income taxes 35,402 (3,099 ) — 32,303 Total non-current assets 243,414 (3,099 ) — 240,315 Total assets $ 587,204 $ 11,590 $ — $ 598,794 Current liabilities Deferred revenue 31,272 (1,059 ) — 30,213 Other current liabilities 40,346 3,695 — 44,041 Total current liabilities 265,792 2,636 — 268,428 Total liabilities $ 374,499 $ 2,636 $ — $ 377,135 Stockholders' equity Retained earnings (deficit) (716 ) 8,954 6,089 14,327 Accumulated other comprehensive income 13,315 — (6,089 ) 7,226 Total stockholders’ equity 212,705 8,954 — 221,659 Total liabilities and stockholders’ equity $ 587,204 $ 11,590 $ — $ 598,794 The impact of ASU No. 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Balance Sheet as of December 31, 2018 , was as follows: December 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Current assets Other current assets $ 29,598 $ 11,461 $ 18,137 Total current assets 450,867 432,730 18,137 Non-current assets Deferred income taxes 34,830 37,929 (3,099 ) Total non-current assets 249,762 252,861 (3,099 ) Total assets $ 700,629 $ 685,591 $ 15,038 Current liabilities Accrued salaries and employee benefits 227,653 224,657 2,996 Deferred revenue 40,673 43,823 (3,150 ) Other current liabilities 33,219 28,224 4,995 Income taxes payable 8,240 7,866 374 Total current liabilities 318,951 313,736 5,215 Total liabilities $ 433,473 $ 428,258 $ 5,215 Stockholders' equity Retained earnings (deficit) 56,049 46,227 9,822 Total stockholders’ equity 267,156 257,334 9,822 Total liabilities and stockholders’ equity $ 700,629 $ 685,591 $ 15,038 The impact of ASU No. 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Comprehensive Income for the three and twelve months ended December 31, 2018 , was as follows: Three Months Ended December 31, 2018 (Unaudited) Twelve Months Ended December 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Revenue Revenue before reimbursements (net revenue) $ 185,305 $ 182,413 $ 2,892 $ 716,023 $ 711,785 $ 4,238 Reimbursements 5,662 5,662 — 19,632 19,632 — Total revenue 190,967 188,075 2,892 735,655 731,417 4,238 Operating expenses Salaries and employee benefits 133,328 131,278 2,050 506,349 503,353 2,996 General and administrative expenses 35,285 35,285 — 140,817 140,817 — Reimbursed expenses 5,662 5,662 — 19,632 19,632 — Total operating expenses 174,275 172,225 2,050 666,798 663,802 2,996 Operating income 16,692 15,850 842 68,857 67,615 1,242 Non-operating income (expense) Interest, net 645 645 — 1,141 1,141 — Other, net (1,355 ) (1,355 ) — 494 494 — Net non-operating income (expense) (710 ) (710 ) — 1,635 1,635 — Income before income taxes 15,982 15,140 842 70,492 69,250 1,242 Provision for income taxes 4,787 4,533 254 21,197 20,823 374 Net income $ 11,195 $ 10,607 $ 588 $ 49,295 $ 48,427 $ 868 Basic earnings per share $ 0.59 $ 0.56 $ 0.03 $ 2.61 $ 2.56 $ 0.05 Diluted earnings per share $ 0.58 $ 0.55 $ 0.03 $ 2.52 $ 2.48 $ 0.04 The impact of ASU 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Cash Flows for the twelve months ended December 31, 2018 , was as follows: Twelve Months Ended December 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Cash flows - operating activities Net income $ 49,295 $ 48,427 $ 868 Changes in assets and liabilities, net of effects of acquisitions: Accrued expenses 71,526 62,372 9,154 Deferred revenue (1,899 ) 3,248 (5,147 ) Income taxes payable, net 757 383 374 Other assets and liabilities, net (4,748 ) (663 ) (4,085 ) Net cash provided by operating activities $ 102,902 $ 102,902 $ —

Revenue (Notes)

Revenue (Notes)	12 Months Ended
	Dec. 31, 2018
Revenue [Abstract]
Revenue from Contracts with Customers [Text Block]	Revenue 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 contain 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. As required under ASU No. 2014-09, the Company now 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: January 1, December 31, Variance Contract assets Unbilled receivables $ 5,487 $ 8,684 $ 3,197 Contract assets 12,398 15,291 2,893 Contract liabilities Deferred revenue $ 30,213 $ 40,673 $ 10,460 During the year ended December 31, 2018, we recognized revenue of $28.0 million that was included in the contract liabilities balance at the beginning of the period. The amount of revenue recognized during the year ended December 31, 2018, from performance obligations partially satisfied in previous periods as a result of changes in the estimates of variable consideration was $21.8 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	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts The activity of the allowance for doubtful accounts for the years ended: December 31, 2018 2017 2016 Balance at January 1, $ 2,534 $ 2,575 $ 5,376 Provision charged to income 3,790 963 1,407 Write-offs (2,708 ) (1,134 ) (4,106 ) Foreign currency translation (114 ) 130 (102 ) Balance at December 31, $ 3,502 $ 2,534 $ 2,575

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net The components of the Company’s property and equipment are as follows: December 31, 2018 2017 Leasehold improvements $ 48,455 $ 48,216 Office furniture, fixtures and equipment 17,919 17,732 Computer equipment and software 27,063 28,300 Property and equipment, gross 93,437 94,248 Accumulated depreciation (59,566 ) (54,734 ) Property and equipment, net $ 33,871 $ 39,514 Depreciation expense for the years ended December 31, 2018 , 2017 and 2016 , was $ 11.0 million , $10.4 million and $9.4 million , respectively.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. A three-level fair value hierarchy prioritizes the inputs used to measure fair value. The hierarchy requires entities to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: • Level 1 – Quoted prices in active markets for identical assets and liabilities. • 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. • Level 3 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets and liabilities. This includes certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. The following tables provide a summary of the fair value measurements at December 31, 2018 and 2017 , for each major category of assets and liabilities measured at fair value on a recurring basis: Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total At December 31, 2018 U.S. non-qualified deferred compensation plan $ 19,442 $ — $ — $ 19,442 Assets designated for retirement and pension plans — 16,384 — 16,384 Pension benefit obligation — (20,908 ) — (20,908 ) Acquisition earnout accruals — — (6,627 ) (6,627 ) $ 19,442 $ (4,524 ) $ (6,627 ) $ 8,291 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total At December 31, 2017 U.S. non-qualified deferred compensation plan $ 21,319 $ — $ — $ 21,319 Assets designated for retirement and pension plans — 18,590 — 18,590 Pension benefit obligation — (23,886 ) — (23,886 ) Acquisition earnout accruals — — (7,213 ) (7,213 ) $ 21,319 $ (5,296 ) $ (7,213 ) $ 8,810 The Level 2 assets above are reinsurance contracts fair valued in accordance with BaFin - German Federal Financial Supervisory Authority guidelines, which utilize observable inputs including mortality tables and discount rates. The Level 3 liabilities are accruals for future earnout payments related to prior year acquisitions, the values of which are determined based on discounted cash flow models. The Company considers the recorded value of its financial assets and liabilities, which consist primarily of cash and cash equivalents, accounts receivable, and accounts payable, to approximate the fair value of the respective assets and liabilities at December 31, 2018 and 2017 , based upon the short-term nature of the assets and liabilities. The following table provides a reconciliation of the beginning and ending balance of Level 3 liabilities for the year ended December 31, 2018 : Acquisition Balance at December 31, 2017 $ (7,213 ) Acquisition earnouts (Note 8) (3,054 ) Earnout accretion (1,285 ) Earnout payments 3,592 Earnout adjustment (1) 888 Foreign currency translation 445 Balance at December 31, 2018 $ (6,627 ) (1) During the twelve months ended December 31, 2018, the Company determined that certain financial targets related to earnout agreements for the DSI and Philosophy IB acquisitions would not be achieved. As such, the Company reduced the earnout accrual accordingly.

Investments

Investments	12 Months Ended
	Dec. 31, 2018
Investments Schedule [Abstract]
Investments	Investments The Company has a U.S. non-qualified deferred compensation plan that consists primarily of U.S. marketable securities and mutual funds, all of which are valued using Level 1 inputs (See Note 7 , Fair Value Measurements ). The fair value for these investments was $ 19.4 million and $ 21.3 million as of December 31, 2018 and 2017 , respectively. The aggregate cost basis for these investments was $ 14.6 million and $ 14.6 million as of December 31, 2018 and 2017 , respectively.

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Acquisition	Acquisitions Decision Strategies International, Inc. On February 29, 2016 , the Company acquired substantially all of the assets of Decision Strategies International, Inc. ("DSI"), a Pennsylvania-based business consulting firm and its wholly owned subsidiary, Decision Strategies International (UK) Limited. The former owners of DSI are eligible to receive an additional cash consideration payment in 2019 based on revenue targets to be achieved in 2017 and 2018. During the year ended December 31, 2018, the Company determined that the final earnout achieved was $2.4 million , and reduced the existing accrual by $0.3 million . Philosophy IB, LLP On September 1, 2016 the Company acquired substantially all of the assets of Philosophy IB, LLP ("Philosophy IB"), a New Jersey-based leadership, organization development and management consulting firm. The former owners of Philosophy IB are eligible to receive additional cash consideration based on two components: (i) achieving revenue milestones generated from its software products from September 2016 through August 2019, and (ii) percentage of consulting revenue achieved over the period September 2016 to August 2019, subject to a profitability test. During the three months ended September 30, 2017, the Company determined that the software and consulting revenue targets for the period from September 2016 to August 2017, or first installment, would not be achieved. As such, the Company reduced the first installment earnout accrual by $0.7 million . During the three months ended September 30, 2018, the Company determined that the software and consulting revenue targets for the period September 2017 to August 2018, or second installment, were not achieved. As such, the Company reduced the second installment by $0.4 million . During the three months ended December 31, 2018, the Company determined that the software and consulting revenue targets for the period from September 2018 to August 2019, or third installment, would not be achieved. As such, the Company reduced the third installment earnout accrual by $0.1 million . Amrop A/S On January 4, 2018 , the Company acquired Amrop A/S ("Amrop"), a Denmark-based provider of executive search services for 24.3 million Danish Kroner (equivalent to $3.9 million on the acquisition date) of initial consideration which was funded from existing cash. The former owners of Amrop are expected to receive additional cash consideration based on fee revenue generated during the two-year period following the completion of the acquisition. When estimating the value of future cash consideration, the Company accrued $3.1 million on the acquisition date. The Company recorded $1.7 million of intangible assets related to customer relationships and $5.5 million of goodwill. The goodwill is primarily related to the acquired workforce and strategic fit.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill The Company's goodwill by segment is as follows: December 31, 2018 December 31, 2017 Executive Search Americas $ 88,410 $ 88,690 Europe 24,924 20,900 Asia Pacific 8,758 9,302 Total Executive Search 122,092 118,892 Heidrick Consulting 36,257 36,257 Goodwill, gross 158,349 155,149 Accumulated impairment (36,257 ) (36,257 ) Goodwill, net $ 122,092 $ 118,892 Changes in the carrying amount of goodwill by segment for the years ended December 31, 2018 , 2017 , and 2016 were as follows: Executive Search Americas Europe Asia Pacific Heidrick Consulting Total Balance at December 31, 2015 $ 81,626 $ 10,745 $ 9,211 $ 29,540 $ 131,122 DSI acquisition 5,673 — — — 5,673 Philosophy IB acquisition 2,357 — — — 2,357 JCA Group acquisition — 15,769 — — 15,769 Segment reallocation (1) (1,670 ) (4,517 ) (347 ) 6,534 — Exchange rate fluctuations 115 (2,905 ) 29 (316 ) (3,077 ) Balance at December 31, 2016 88,101 19,092 8,893 35,758 151,844 Philosophy IB acquisition 357 — — 7 364 Exchange rate fluctuations 232 1,808 409 492 2,941 Impairment — — — (36,257 ) (36,257 ) Balance at December 31, 2017 88,690 20,900 9,302 — 118,892 Amrop acquisition — 5,478 — — 5,478 Foreign currency translation (280 ) (1,454 ) (544 ) — (2,278 ) Balance at December 31, 2018 $ 88,410 $ 24,924 $ 8,758 $ — $ 122,092 (1) Due to the Company's change in segment reporting during the year ended December 31, 2016, goodwill amounts included in the Company's Americas, Europe and Asia Pacific segments in the prior year have been reallocated to the Heidrick Consulting segment utilizing the relative fair value method. During the twelve months ended December 31, 2017 , the Company determined that the goodwill within the Culture Shaping and Leadership Consulting reporting units was impaired, which resulted in impairment charges of $29.3 million and $6.9 million , respectively, to write off all of the goodwill associated with each of the reporting units. The impairment charges are recorded within Impairment charges in the Condensed Consolidated Statements of Comprehensive Income (Loss) for the twelve months ended December 31, 2017 . The impairments were non-cash in nature and did not affect our current liquidity, cash flows, borrowing capability or operations, nor did they impact the debt covenants under our credit agreement. Effective January 1, 2018, the Company completed its integration of the Culture Shaping and Leadership Consulting reporting units into the newly created Heidrick Consulting reporting unit. On January 4, 2018, the Company acquired Amrop and included the fair value of the acquired assets and liabilities as of the acquisition date in the Condensed Consolidated Balance Sheets. The Company included $5.5 million of goodwill related to the acquisition in the Europe segment. During the 2018 fourth quarter, the Company conducted its annual goodwill impairment evaluation as of October 31, 2018 in accordance with ASU No. 2017-04, Intangibles - Goodwill and Other. The goodwill impairment test is completed by comparing the fair value of a reporting unit with its carrying amount. An impairment charge is recognized for the amount by which the carrying value of the reporting unit exceeds its fair value; however, the loss recognized is not to exceed the total amount of goodwill allocated to that reporting unit. The impairment test is considered for each of the Company’s reporting units that has goodwill as defined in the accounting standard for goodwill and intangible assets. The Company operates four reporting units: Americas, Europe (which includes Africa), Asia Pacific (which includes the Middle East) and Heidrick Consulting. As of October 31, 2018, only the Americas, Europe and Asia Pacific reporting units had recorded goodwill. During the impairment evaluation process, the Company used a discounted cash flow methodology to estimate the fair value of each of its reporting units with goodwill. The discounted cash flow approach is dependent on a number of factors, including estimates of future market growth and trends, forecasted revenue and costs, capital investments, appropriate discount rates, certain assumptions to allocate shared costs, assets and liabilities, historical and projected performance of the reporting unit and the macroeconomic conditions affecting each of the Company’s reporting units. The assumptions used in the determination of fair value were (1) a forecast of growth in the near and long term; (2) the discount rate; (3) working capital investments; and (4) other factors. Based on the results of the impairment analysis, the fair values of the Americas, Europe, and Asia Pacific reporting units exceeded their carrying values by 335% , 19% and 13% , respectively. Other Intangible Assets, net The Company’s other intangible assets, net by segment, are as follows: December 31, 2018 December 31, 2017 Executive Search Americas $ 52 $ 252 Europe 2,086 1,799 Asia Pacific 78 107 Total Executive Search 2,216 2,158 Heidrick Consulting — — Total Other Intangible Assets, Net $ 2,216 $ 2,158 During the twelve months ended December 31, 2017 , the Company determined that the intangible assets within the Culture Shaping and Leadership Consulting reporting units were impaired, which resulted in impairment charges of $9.9 million and $4.6 million , respectively, to write off all intangible assets associated with each reporting unit. The impairment charges are recorded within Impairment charges in the Condensed Consolidated Statement of Comprehensive Income (Loss) for the twelve months ended December 31, 2017 . The impairment charges were non-cash in nature and did not affect current liquidity, cash flows, borrowing capability or operations, nor did they impact the debt covenants under our credit agreement. Effective January 1, 2018, the Company completed its integration of the Culture Shaping and Leadership Consulting reporting units into the newly created Heidrick Consulting reporting unit. The carrying amount of amortizable intangible assets and the related accumulated amortization were as follows: December 31, 2018 December 31, 2017 Weighted Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Carrying Amount Client relationships 6.8 $ 15,910 $ (13,694 ) $ 2,216 $ 13,703 $ (11,612 ) $ 2,091 Trade name 0.0 434 (434 ) — 459 (459 ) — Non-compete 0.0 217 (217 ) — 230 (163 ) 67 Total intangible assets 6.8 $ 16,561 $ (14,345 ) $ 2,216 $ 14,392 $ (12,234 ) $ 2,158 Intangible asset amortization expense for the years ended December 31, 2018 , 2017 and 2016 , was $1.5 million , $4.4 million and $7.1 million , respectively. The Company's estimated future amortization expense related to intangible assets as of December 31, 2018 for the years ended December 31st is as follows: 2019 $ 846 2020 529 2021 356 2022 241 2023 147 Thereafter 97 Total $ 2,216

Other Current Assets and Liabil

Other Current Assets and Liabilities and Non-Current Liabilities	12 Months Ended
	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Other Non-Current Liabilities	Other Current Assets and Liabilities and Non-Current Liabilities The components of other current assets are as follows: December 31, 2018 December 31, 2017 Contract assets $ 23,975 $ 3,538 Other 5,623 8,082 Total other current assets $ 29,598 $ 11,620 The components of other current liabilities are as follows: December 31, 2018 December 31, 2017 Restructuring charges $ 1,287 $ 13,023 Other 31,932 27,323 Total other current liabilities $ 33,219 $ 40,346 The components of other non-current liabilities are as follows: December 31, 2018 December 31, 2017 Premise related costs $ 15,473 $ 18,360 Accrued earnout payments — 3,076 Restructuring charges — 10 Other 1,950 2,151 Total other non-current liabilities $ 17,423 $ 23,597

Line of Credit

Line of Credit	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Line of Credit	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 remaining term of the agreement. Before October 26, 2018, the Company was party to its 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 includes 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. During the three months ended March 31, 2017, the Company borrowed $40 million under the Restated Credit Agreement and elected the Adjusted LIBOR rate. The Company subsequently repaid $15 million during the three months ended March 31, 2017 and $25 million during the three months ended June 30, 2017. As of December 31, 2018 and 2017 , the Company had no outstanding borrowings under either the 2018 Credit Agreement or the Restated Credit Agreement. The Company was in compliance with the financial and other covenants under both facilities and no event of default existed.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2018
Postemployment Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans Qualified Retirement Plan The Company has a defined contribution retirement plan (the “Plan”) for all eligible employees in the United States. Eligible employees may begin participating in the Plan upon their hire date. The Plan contains a 401(k) provision, which provides for employee pre-tax and/or after-tax contributions, from 1% to 50% of their eligible compensation up to a combined maximum permitted by law. The Company matched employee contributions on a dollar-for-dollar basis per participant up to the greater of $6,000 , or 6.0% , of eligible compensation for the years ended December 31, 2018, 2017 and 2016. Beginning in 2016, employees are eligible for the Company match immediately provided that they are working on the last day of the Plan year in which the match is made. Previously, employees were eligible for the Company match after satisfying a one -year service requirement provided that they were working on the last day of the Plan year in which the match was made. The Plan also provides for employees who retire, die or become disabled during the Plan year to receive the Company match for that Plan year. The Plan provides that forfeitures will be used to reduce the Company’s contributions. Forfeitures are created annually by participants who terminate employment before becoming entitled to the Company’s matching contribution under the Plan. The Company also has the option of making discretionary contributions. There were no discretionary contributions made for the years ended December 31, 2018 , 2017 and 2016 . The expense that the Company incurred for matching employee contributions for the years ended December 31, 2018 , 2017 and 2016 , was $5.7 million , $5.6 million and $4.8 million , respectively. The Company maintains additional retirement plans in the Americas, Europe and Asia Pacific regions which the Company does not consider as material and, therefore, additional disclosure has not been presented. Deferred Compensation Plans The Company has a deferred compensation plan for certain U.S. employees (the “U.S. Plan”) that became effective on January 1, 2006. The U.S. Plan allows participants to defer up to 25% of their base compensation and up to the lesser of $500,000 or 25% of their eligible bonus compensation into several different investment vehicles. These deferrals are immediately vested and are not subject to a risk of forfeiture. In 2018 and 2017 , all deferrals in the U.S. Plan were funded. The compensation deferred in the U.S. Plan was $18.3 million and $19.2 million at December 31, 2018 and 2017 , respectively. The assets of the U.S. Plan are included in Investments and the liabilities of the U.S. Plan are included in Retirement and pension plans in the Consolidated Balance Sheets as of December 31, 2018 and 2017 . The Company has a Non-Employee Directors Voluntary Deferred Compensation Plan whereby non-employee members of the Company’s Board of Directors may elect to defer up to 100% of the cash component of their directors’ fees into several different investment vehicles. As of December 31, 2018 and 2017 , the total amounts deferred under the plan were $1.1 million and $2.2 million , respectively, all of which were funded. The assets of the plan are included in Investments and the liabilities of the plan are included in Retirement and pension plans in the Consolidated Balance Sheets at December 31, 2018 and 2017 . The U.S. and Non-Employee Directors Voluntary Deferred Compensation Plans consist primarily of marketable securities and mutual funds, all of which are valued using Level 1 inputs (See Note 7 , Fair Value Measurements ).

Pension Plan and Life Insurance

Pension Plan and Life Insurance Contract Pension Plan and Life Insurance Contract (Notes)	12 Months Ended
	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Disclosure [Text Block]	Pension Plan and Life Insurance Contract The Company 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. 2018 2017 Benefit obligation at January 1, $ 23,886 $ 22,128 Interest cost 373 362 Actuarial (gain) loss (886 ) (371 ) Benefits paid (1,450 ) (1,453 ) Cumulative translation adjustment (1,015 ) 3,220 Benefit obligation at December 31, $ 20,908 $ 23,886 The benefit obligation amounts recognized in the Consolidated Balance Sheets are as follows: December 31, 2018 2017 Current liabilities $ 1,349 $ 1,461 Noncurrent liabilities 19,559 22,425 Total $ 20,908 $ 23,886 The accumulated benefit obligation amounts at December 31, 2018 and 2017 , are $20.9 million and $23.9 million , respectively. The components of and assumptions used to determine the net periodic benefit cost are as follows: December 31, 2018 2017 2016 Net period benefit cost: Interest cost $ 373 $ 362 $ 453 Amortization of net loss 92 111 17 Net periodic benefit cost $ 465 $ 473 $ 470 Weighted average assumptions Discount rate (1) 1.64 % 1.49 % 2.15 % Rate of compensation increase — % — % — % Assumptions to determine the Company’s benefit obligation are as follows: December 31, 2018 2017 2016 Discount rate (1) 1.71 % 1.64 % 1.53 % Rate of compensation increase — % — % — % Measurement Date 12/31/2018 12/31/2017 12/31/2016 (1) The discount rates are based on long-term bond indices adjusted to reflect the longer duration of the benefit obligation. The amounts in Accumulated other comprehensive income as of December 31, 2018 and 2017 , that had not yet been recognized as components of net periodic benefit cost were $2.6 million and $3.7 million , respectively. As of December 31, 2018, an insignificant amount of the accumulated other comprehensive income is expected to be recognized as a component of net periodic benefit cost in 2019. 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 (See Note 7, Fair Value Measurements ). The fair value at December 31, 2018 and 2017 , was $ 16.4 million and $ 18.6 million , respectively. The expected contribution to be paid into the plan in 2019 is $1.3 million . Since the pension assets are not segregated in trust from the Company’s other assets, the pension assets are not shown as an offset against the pension liabilities in the Consolidated Balance Sheets. These assets are included in the Consolidated Balance Sheets at December 31, 2018 and 2017 , as a component of Other current assets and Assets designated for retirement and pension plans . The benefits expected to be paid in each of the next five years, and in the aggregate for the five years thereafter are as follows: 2019 $ 1,349 2020 1,339 2021 1,326 2022 1,309 2023 1,289 2024 through 2028 6,001

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company's 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 December 31, 2018 , 2,149,864 shares have been issued under the 2012 Program and 1,375,105 shares remain available for future awards, which includes 674,969 forfeited shares. The 2012 Program provides that no awards can be granted after May 24, 2028 . In September 2017, the Company entered into an agreement with its former Chief Executive Officer pursuant to which Mr. Wolstencroft voluntarily agreed, with the concurrence of the Board of Directors, to forfeit 100 percent of his 2017 restricted stock unit and performance stock unit grants. Mr. Wolstencroft remains eligible to continue vesting in 100 percent of his 2014 sign-on restricted stock unit grant, without proration, subject to his continued service on the board through the future scheduled vesting dates. With respect to his outstanding 2015 and 2016 restricted stock unit and performance stock unit grants, Mr. Wolstencroft remains eligible to earn an agreed upon pro-rata portion of the tranches scheduled to vest in 2017, 2018 and 2019, subject to his continued service as a director through the scheduled vesting dates (and with the performance goals for performance stock units deemed to have been achieved at target level performance), and he agreed to forfeit the remaining portions of such 2015 and 2016 restricted stock unit and performance stock unit awards. 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: December 31, 2018 2017 2016 Salaries and employee benefits (1) $ 9,548 $ 4,597 $ 5,830 General and administrative expenses 562 338 563 Income tax benefit related to stock-based compensation included in net income 2,674 1,948 2,523 (1) Includes $1.2 million of expense related to cash settled restricted stock units for the year ended December 31, 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 as of December 31, 2018 , 2017 and 2016 is as follows: Number of Weighted- Outstanding on December 31, 2015 473,935 $ 19.98 Granted 207,405 22.92 Vested and converted to common stock (119,455 ) 20.02 Forfeited (24,612 ) 22.81 Outstanding on December 31, 2016 537,273 20.97 Granted 243,306 24.18 Vested and converted to common stock (217,028 ) 21.39 Forfeited (72,397 ) 24.05 Outstanding on December 31, 2017 491,154 21.92 Granted 297,664 34.64 Vested and converted to common stock (199,550 ) 21.66 Forfeited (76,822 ) 25.76 Outstanding on December 31, 2018 512,446 28.83 As of December 31, 2018 , there was $5.9 million of pre-tax unrecognized compensation expense related to unvested restricted stock units, which is expected to be recognized over a weighted average of 2.6 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% - 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. Performance share unit activity as of December 31, 2018 , 2017 and 2016 is as follows: Number of Weighted- Outstanding on December 31, 2015 272,024 $ 18.28 Granted 125,388 22.98 Vested and converted to common stock (160,600 ) 15.51 Forfeited — — Outstanding on December 31, 2016 236,812 22.64 Granted 88,415 23.83 Vested and converted to common stock (70,652 ) 19.65 Forfeited (68,684 ) 24.07 Outstanding on December 31, 2017 185,891 23.82 Granted 102,138 25.81 Vested and converted to common stock (43,361 ) 23.64 Forfeited (47,551 ) 23.87 Outstanding on December 31, 2018 197,117 24.88 As of December 31, 2018 , there was $2.0 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 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. During the year ended December 31, 2018 , phantom stock with respect to 111,673 shares of common stock were granted to certain employees of the Company, and are subject to vesting over a period of 4 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. As of December 31, 2018, the Company has recorded a liability of approximately $1.2 million related to the phantom stock units, which is recorded in non-current Accrued salaries and employee benefits in the Consolidated Balance Sheets. The fair value of the phantom stock awards as of December 31, 2018 , was determined using the closing share price of the Company's common stock on that date. Phantom stock unit activity as of December 31, 2018 is as follows: Number of Stock Units Outstanding on December 31, 2017 — Granted 111,673 Vested — Forfeited — Outstanding on December 31, 2018 111,673 Expense associated with the phantom stock units was $1.2 million for the year ended December 31, 2018. As of December 31, 2018 , there was $2.0 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 . No phantom stock units were granted during the years ended December 31, 2017 and 2016.

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Changes in Accumulated Other Comprehensive Income	Changes in Accumulated Other Comprehensive Income The changes in Accumulated other comprehensive income (“AOCI”) by component for the year ended December 31, 2018 , are summarized below: Available- Foreign Pension AOCI Balance at December 31, 2017 $ 6,089 $ 9,143 $ (1,917 ) $ 13,315 Other comprehensive income before classification, net of tax — (3,885 ) 721 (3,164 ) Amount reclassified from AOCI — — — — Net current period other comprehensive income — (3,885 ) 721 (3,164 ) Adoption of accounting standards (1) (6,089 ) — — (6,089 ) Balance at December 31, 2018 — $ 5,258 $ (1,196 ) $ 4,062 (1) Upon adoption of ASC 2016-01, unrealized gains (losses) on available for sale securities were reclassified from AOCI to retained earnings

Restructuring (Notes)

Restructuring (Notes)	12 Months Ended
	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Activities Disclosure [Text Block]	Restructuring Restructuring Charges 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. These charges consisted of $13.1 million of employee-related costs, including severance associated with reductions in our workforce of 251 employees globally, $2.3 million of other professional and consulting fees and $0.3 million of expenses associated with closing three office locations. Restructuring charges by operating segment for the year ended December 31, 2017, are as follows: Restructuring Charges Executive Search Americas $ 784 Europe 3,993 Asia Pacific 2,046 Total Executive Search 6,823 Heidrick Consulting 3,393 Global Operations Support 5,450 Total restructuring $ 15,666 The accrued restructuring charges at December 31, 2018 , primarily consists of employee-related costs that require cash payments based on individual severance agreements. These accruals are included within Other current liabilities in the Consolidated Balance Sheets at December 31, 2018 . The table below outlines the restructuring charges along with related cash payments for the years ended December 31, 2018 and 2017 : Employee Related Office Related Other Total Accrual balance at December 31, 2016 $ — $ — $ — $ — Restructuring charges 13,065 308 2,293 15,666 Cash payments (1,199 ) (5 ) (1,282 ) (2,486 ) Non cash write-offs — (155 ) — (155 ) Accrual balance at December 31, 2017 $ 11,866 $ 148 $ 1,011 $ 13,025 Cash payments (8,689 ) (248 ) (993 ) (9,930 ) Non cash write-offs — 195 — 195 Other (1,843 ) (95 ) 5 (1,933 ) Exchange rate fluctuations (65 ) — (6 ) (71 ) Accrual balance at December 31, 2018 $ 1,269 $ — $ 17 $ 1,286

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The sources of income (loss) before income taxes are as follows: December 31, 2018 2017 2016 United States $ 47,191 $ (28,577 ) $ 30,696 Foreign 23,301 (841 ) 7,070 Income (loss) before income taxes $ 70,492 $ (29,418 ) $ 37,766 The provision for (benefit from) income taxes are as follows: December 31, 2018 2017 2016 Current Federal $ 12,311 $ 10,107 $ 12,261 State and local 4,843 2,372 3,219 Foreign 6,907 8,257 5,668 Current provision for income taxes 24,061 20,736 21,148 Deferred Federal 6,403 5,642 727 State and local (354 ) (2,951 ) (370 ) Foreign (8,913 ) (4,210 ) 848 Deferred provision (benefit) for income taxes (2,864 ) (1,519 ) 1,205 Total provision for income taxes $ 21,197 $ 19,217 $ 22,353 A reconciliation of the provision for income taxes to income taxes at the statutory U.S. federal income tax rate of 21% is as follows: December 31, 2018 2017 2016 Income tax provision (benefit) at the statutory U.S. federal rate $ 14,803 $ (10,296 ) $ 13,218 State income tax provision (benefit), net of federal tax benefit 3,242 (593 ) 1,904 Nondeductible expenses, net 2,587 3,282 1,410 Foreign taxes (includes rate differential and changes in foreign valuation allowance) (35 ) 5,465 (2,133 ) Establishment (release) of valuation allowance (43 ) (3,200 ) 340 U.S. tax on foreign dividends 765 — 5,898 Current/deferred true-up (1,199 ) 567 1,226 Tax reform — 23,732 — Other, net 1,077 260 490 Total provision for income taxes $ 21,197 $ 19,217 $ 22,353 The deferred tax assets and liabilities are attributable to the following components: December 31, 2018 2017 Deferred tax assets attributable to: Foreign net operating loss carryforwards $ 18,259 $ 31,960 Accrued compensation and employee benefits 15,442 15,809 Deferred compensation 15,587 13,600 Foreign tax credit carryforwards 8,163 8,128 Accrued rent 3,096 3,607 Other accrued expenses 6,290 2,179 Deferred tax assets, before valuation allowance 66,837 75,283 Valuation allowance (26,460 ) (35,624 ) Deferred tax assets, after valuation allowance 40,377 39,659 Deferred tax liabilities attributable to: Goodwill 2,203 306 Taxes provided on unremitted earnings 765 129 Depreciation on property and equipment 2,040 3,216 Other 686 606 Deferred tax liabilities 5,694 4,257 Net deferred tax assets $ 34,683 $ 35,402 The recognition of deferred tax assets is based on management’s belief that it is more likely than not that the tax benefits associated with temporary differences, net operating loss carryforwards and tax credits will be utilized. The Company assesses the recoverability of the deferred tax assets on an ongoing basis. In making this assessment, the Company considers all positive and negative evidence, and all potential sources of taxable income including scheduled reversals of deferred tax liabilities, tax-planning strategies, projected future taxable income and recent financial performance. The valuation allowance decreased from $35.6 million at December 31, 2017 to $26.5 million at December 31, 2018 . The valuation allowance at December 31, 2018 was related to foreign net operating loss carryforwards, foreign tax credit carryforwards and certain foreign deferred tax assets. The Company intends to maintain these valuation allowances until sufficient evidence exists to support their reversal. At December 31, 2018 , the Company had a net operating loss carryforward of $118.0 million related to its foreign tax filings and $0.1 million related to its U.S. state tax filings. Of the $118.0 million net operating loss carryforward, $59.8 million is subject to a valuation allowance. Depending on the tax rules of the tax jurisdictions, the losses can be carried forward indefinitely or for periods ranging from five to twenty years. The Company also has a foreign tax credit carryforward of $8.2 million subject to a valuation allowance of $8.2 million . At December 31, 2017 , the Company had a net operating loss carryforward of $126.0 million related to its foreign tax filings and $0.1 million related to its U.S. state tax filings. Of the $126.0 million net operating loss carryforward, $95.4 million is subject to a valuation allowance. Depending on the tax rules of the tax jurisdictions, the losses can be carried forward indefinitely or for periods ranging from five to twenty years. The Company also has a foreign tax credit carryforward of $8.1 million subject to a valuation allowance of $8.1 million . As of December 31, 2018 , the Company had unremitted earnings held in its foreign subsidiaries of approximately $75.5 million , of which the company has provided $0.9 million of tax on $7.2 million of earnings that are intended to be remitted. The Company did not recognize a tax liability for income taxes and foreign withholding taxes related to the unremitted earnings of its foreign operations because the Company intends to reinvest those earnings indefinitely, net of any allowable deductions. An estimate of these taxes, however, is not practicable. A tax liability will be recognized if and when the Company is no longer able to demonstrate that it plans to permanently reinvest unremitted earnings. As of December 31, 2017 , the Company had unremitted earnings held in its foreign subsidiaries of approximately $74.1 million , of which the company has provided $1.6 million of tax on $15.7 million of earnings that are intended to be remitted. The Company did not recognize a tax liability for income taxes and foreign withholding taxes related to the unremitted earnings of its foreign operations because the Company intends to reinvest those earnings indefinitely, net of any allowable deductions. An estimate of these taxes, however, is not practicable. A tax liability will be recognized if and when the Company is no longer able to demonstrate that it plans to permanently reinvest unremitted earnings. As of January 1, 2018, the Company had $0.7 million of unrecognized tax benefits. As of December 31, 2018 , the Company had $1.1 million of unrecognized tax benefits of which, if recognized, would be recorded as a component of income tax expense. A reconciliation of the beginning and ending balances of the total amounts of gross unrecognized tax benefits is as follows: December 31, 2018 2017 2016 Gross unrecognized tax benefits at January 1, $ 740 $ 1,038 $ 130 Gross increases for tax positions of prior years 608 167 2,146 Gross decreases for tax positions of prior years — — (4 ) Settlements (220 ) (465 ) (1,234 ) Lapse of statute of limitations — — — Gross unrecognized tax benefits at December 31, $ 1,128 $ 740 $ 1,038 In many cases the Company’s uncertain tax positions are related to tax years that remain subject to examination by the relevant taxable authorities. Years 2015 through 2017 are subject to examination by the state taxing authorities. The years 2015 and 2017 are subject to examination by the federal taxing authority. There are certain foreign jurisdictions that are subject to examination for years prior to 2014. The Company is currently under audit by some jurisdictions. It is likely that the examination phase of several of these audits will conclude in the next twelve months. No significant increases or decreases in unrecognized tax benefits are expected to occur by December 31, 2019. Estimated interest and penalties related to the underpayment of income taxes are classified as a component of the provision for income taxes in the Consolidated Statements of Comprehensive Income (Loss). Accrued interest and penalties are $0.4 million as of December 31, 2018 . The Global Intangible Low-Taxed Income ("GILTI") provisions require the Company to include in its U.S. income tax return foreign subsidiary earnings in excess of an allowable return on the foreign subsidiary’s tangible assets. The Company became subject to incremental U.S. tax on GILTI income beginning in 2018 due to expense allocations required by the U.S. foreign tax credit rules. The Company has elected to account for GILTI tax in the period in which it is incurred, and therefore has not provided any deferred tax impacts of GILTI in its consolidated financial statements for the year ended December 31, 2018. The Base Erosion and Anti-Abuse Tax ("BEAT") provisions in the Tax Reform Act eliminates the deduction of certain base-erosion payments made to related foreign corporations, and impose a minimum tax if greater than regular tax. The Company does not expect it will be subject to this tax and therefore has not included any tax impacts of BEAT in its consolidated financial statements for the year ended December 31, 2018.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segment Information	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 Leadership Consulting and Culture Shaping as one operating segment, Heidrick Consulting. In conjunction with the change in operating segments, the Company modified its corporate cost allocation methodology. Previously reported operating segment results for the twelve months ended December 31, 2017 and 2016, have been recast to conform to the new operating segment structure and corporate cost allocation methodology. 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 (loss) more appropriately reflects its core operations. The revenue, operating income, depreciation and amortization, and capital expenditures, by segment, are as follows: December 31, 2018 2017 2016 Revenue Executive Search Americas $ 405,267 $ 339,793 $ 313,292 Europe 145,348 125,346 108,754 Asia Pacific 102,276 86,905 85,319 Total Executive Search 652,891 552,044 507,365 Heidrick Consulting 63,132 69,356 75,025 Revenue before reimbursements 716,023 621,400 582,390 Reimbursements 19,632 18,656 18,516 Total revenue $ 735,655 $ 640,056 $ 600,906 Operating Income (Loss) Executive Search Americas (1) $ 96,880 $ 75,337 $ 71,993 Europe (2) 5,849 13 5,943 Asia Pacific (3) 15,999 537 3,944 Total Executive Search 118,728 75,887 81,880 Heidrick Consulting (4) (13,619 ) (62,368 ) (5,322 ) Total segments 105,109 13,519 76,558 Global Operations Support (5) (36,252 ) (40,042 ) (41,325 ) Total operating income (loss) $ 68,857 $ (26,523 ) $ 35,233 Depreciation and Amortization Executive Search Americas $ 4,605 $ 4,794 $ 3,892 Europe 3,735 3,328 2,478 Asia Pacific 1,646 1,565 1,774 Total Executive Search 9,986 9,687 8,144 Heidrick Consulting 1,577 4,099 6,842 Total segments 11,563 13,786 14,986 Global Operations Support 959 988 1,447 Total depreciation and amortization $ 12,522 $ 14,774 $ 16,433 Capital Expenditures Executive Search Americas $ 601 $ 7,123 $ 2,221 Europe 3,557 1,460 835 Asia Pacific 440 2,633 3,346 Total Executive Search 4,598 11,216 6,402 Heidrick Consulting 581 1,172 659 Total segments 5,179 12,388 7,061 Global Operations Support 1,006 3,298 1,321 Total capital expenditures $ 6,185 $ 15,686 $ 8,382 (1) Operating income for the Americas includes $0.8 million of restructuring charges in 2017. (2) Operating income for Europe includes $4.0 million of restructuring charges in 2017. (3) Operating income for Asia Pacific includes $2.0 million of restructuring charges in 2017. (4) Operating loss for Heidrick Consulting includes $50.7 million of impairment charges and $3.4 million of restructuring charges in 2017. (5) Operating loss for Global Operations Support includes $5.5 million of restructuring charges in 2017. Identifiable assets, and goodwill and other intangible assets, net, by segment, are as follows: December 31, 2018 2017 Current assets Executive Search Americas $ 255,889 $ 171,985 Europe 85,355 84,405 Asia Pacific 74,169 55,196 Total Executive Search 415,413 311,586 Heidrick Consulting 34,174 31,116 Total segments 449,587 342,702 Global Operations Support 1,280 1,088 Total allocated current assets 450,867 343,790 Unallocated non-current assets 125,454 122,364 Goodwill and other intangible assets, net Executive Search Americas 88,462 88,942 Europe 27,010 22,699 Asia Pacific 8,836 9,409 Total Executive Search 124,308 121,050 Heidrick Consulting — — Total goodwill and other intangible assets, net 124,308 121,050 Total assets $ 700,629 $ 587,204

Guarantees

Guarantees	12 Months Ended
	Dec. 31, 2018
Guarantees [Abstract]
Guarantees	Guarantees The Company has issued cash collateralized bank guarantees and letter of credit backed bank guarantees supporting certain obligations, primarily the payment of office lease obligations and business license requirements for certain of its subsidiaries in Europe and Asia Pacific. The bank guarantees were made to secure the respective agreements and are for the terms of the agreements, which extend through 2024 . For each bank guarantee issued, the Company would have to perform under the guarantee if the subsidiary defaults on a lease payment. The maximum amount of undiscounted payments the Company would be required to make in the event of default on all outstanding bank guarantees is approximately $2.6 million as of December 31, 2018 . 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	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases The Company leases office space in 49 cities in 25 countries. The terms of these office-related leases provide that the Company pay base rent and a share of operating expenses and real estate taxes in excess of defined amounts. These leases expire at various dates through 2026. The Company also leases certain computer equipment and cars, the terms of which are accounted for as operating leases. Rent expense, which includes the base rent, maintenance costs, operating expenses and real estate taxes, and the costs of equipment leases for the years ended December 31, 2018 , 2017 and 2016 , was $ 33.2 million , $32.2 million and $ 30.8 million , respectively. Minimum future operating lease payments due in each of the next five years and thereafter are as follows: 2019 $ 34,456 2020 31,808 2021 27,381 2022 23,445 2023 20,087 Thereafter 14,448 Total $ 151,625 The aggregate minimum future payments on office leases are $150.1 million . The Company has contractual arrangements to receive aggregate sublease income of $0.2 million related to certain leases that expire at various dates through 2019. This sublease income primarily relates to properties that were part of prior office consolidations and closings. Certain leases provide for renewal options and payments of real estate taxes and other occupancy costs. In addition, certain leases contain rent escalation clauses that require additional rental amounts in later years of the term. Rent expense for leases with rent escalation clauses is recognized on a straight-line basis over the minimum lease term. The Company has an obligation at the end of the lease term to return certain offices to the landlord in its original condition, which is recorded at fair value at the time the liability is incurred. The Company had $2.7 million and $2.9 million of asset retirement obligations as of December 31, 2018 and 2017 , respectively, which are recorded within Other current liabilities and Other non-current liabilities in the Consolidated Balance Sheets. 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)	12 Months Ended
	Dec. 31, 2018
Reclassifications [Line Items]
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid instruments with an original maturity of three months or less to be cash equivalents.
Concentration of Risk	Concentration of Risk The Company is potentially exposed to concentrations of risk associated with its accounts receivable. However, this risk is limited due to the Company’s large number of clients and their dispersion across many different industries and geographies. At December 31, 2018 and 2017, the Company had no significant concentrations of risk.
Accounts Receivable	Accounts Receivable The Company’s accounts receivable consist of trade receivables. The allowance for doubtful accounts is developed based upon several factors including the age of the Company’s accounts receivable, historical write-off experience and specific account analysis. These factors may change over time, impacting the allowance level.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Cash equivalents are stated at cost, which approximates fair value. The carrying value for receivables from clients, accounts payable, deferred revenue and other accrued liabilities reasonably approximate fair value due to the nature of the financial instruments and the short term nature of the items.
Property and Equipment	Property and Equipment Property and equipment are stated at cost. Depreciation is computed using the straight-line method over the estimated useful life of the asset or, for leasehold improvements, the shorter of the lease term or the estimated useful life of the asset, as follows: Office furniture, fixtures and equipment 5–10 years Computer equipment and software 3–7 years Leasehold improvements are depreciated over the lesser of the lease term or life of the asset improvement, which typically range from three to ten years. Depreciation is calculated for tax purposes using accelerated methods, where applicable. Property and Equipment Property and equipment are stated at cost. Depreciation is computed using the straight-line method over the estimated useful life of the asset or, for leasehold improvements, the shorter of the lease term or the estimated useful life of the asset, as follows: Office furniture, fixtures and equipment 5–10 years Computer equipment and software 3–7 years Leasehold improvements are depreciated over the lesser of the lease term or life of the asset improvement, which typically range from three to ten years. Depreciation is calculated for tax purposes using accelerated methods, where applicable.
Long-lived Assets	Long-lived Assets The Company reviews its long-lived assets, including property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge, equal to the amount by which the carrying amount of the asset exceeds the fair value of the asset, is recognized.
Investments	Investments The Company’s investments consist primarily of available-for-sale investments within the U.S. non-qualified deferred compensation plan (the “Plan”). Available-for-sale investments are reported at fair value with changes in unrealized gains (losses) and realized gains (losses), resulting from an employee’s termination from the Plan, recorded as a non-operating expense in Other, net in the Consolidated Statements of Comprehensive Income (Loss).
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the difference between the purchase price of acquired companies and the related fair value of the net assets acquired, which is accounted for by the acquisition method of accounting. Other intangible assets include client relationships and employee non-compete agreements. The Company performs assessments of the carrying value of goodwill at least annually and of its goodwill and other intangible assets whenever events occur or circumstances indicate that a carrying amount of these assets may not be recoverable. These circumstances include a significant change in business climate, attrition of key personnel, changes in financial condition or results of operations, a prolonged decline in the Company’s stock price and market capitalization, competition, and other factors. The goodwill impairment test compares the fair value of a reporting unit to its carrying amount, including goodwill. The Company operates four reporting units: Americas, Europe (which includes Africa), Asia Pacific (which includes the Middle East) and Heidrick Consulting. The goodwill impairment test is completed by comparing the fair value of a reporting unit with its carrying amount. The fair value of each of the Company’s reporting units is determined using a discounted cash flow methodology. An impairment charge is recognized for the amount by which the carrying value of the reporting unit exceeds its fair value; however, the loss recognized is not to exceed the total amount of goodwill allocated to that reporting unit. The other intangible asset impairment review compares the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge, equal to the amount by which the carrying amount of the asset exceeds the fair value, is recognized. Other intangible assets acquired are amortized either using the straight-line method over their estimated useful lives or based on the projected cash flow associated with the respective intangible assets.
Restructuring Charges	Restructuring Charges The Company accounts for restructuring charges by recognizing a liability at fair value when the costs are incurred.
Reimbursements	Reimbursements The Company incurs certain out-of-pocket expenses that are reimbursed by its clients, which are accounted for as revenue and expense in its Consolidated Statements of Comprehensive Income (Loss).
Salaries and Employee Benefits	Salaries and Employee Benefits Salaries and employee benefits consist of compensation and benefits paid to consultants, executive officers, and administrative and support personnel, of which the most significant elements are salaries and annual performance-related bonuses. Other items in this category are expenses related to sign-on bonuses, forgivable employee loans and minimum guaranteed bonuses (often incurred in connection with the hiring of new consultants), restricted stock unit and performance share unit amortization, payroll taxes, profit sharing and retirement benefits, and employee insurance benefits. Salaries and employee benefits are recognized on an accrual basis. Certain sign-on bonuses, retention awards, and minimum guaranteed compensation are capitalized and amortized in accordance with the terms of the respective agreements. A portion of the Company’s consultants’ and management cash bonuses are deferred and paid over a three -year vesting period. The portion of the bonus is approximately 15% depending on the employee’s level or position. The compensation expense related to the amounts being deferred is recognized on a graded vesting attribution method over the requisite service period. This service period begins on January 1 of the respective fiscal year and continues through the deferral date, which coincides with the Company’s bonus payments in the first quarter of the following year and for an additional three -year vesting period. The deferrals are recorded in Accrued salaries and employee benefits within both Current liabilities and Non-current liabilities in the Consolidated Balance Sheets.
Income Taxes	Income Taxes Deferred tax assets and liabilities are determined based on the differences between the financial statement and tax basis of assets and liabilities, applying enacted statutory tax rates in effect for the year in which the tax differences are expected to reverse. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment.
Earnings per Common Share	Earnings per Common Share Basic earnings per common share is computed by dividing net income by weighted average common shares outstanding for the year. 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 (loss) per share: December 31, 2018 2017 2016 Net income (loss) $ 49,295 $ (48,635 ) $ 15,413 Weighted average shares outstanding: Basic 18,917 18,735 18,540 Effect of dilutive securities: Restricted stock units 406 — 347 Performance stock units 209 — 151 Diluted 19,532 18,735 19,038 Basic earnings (loss) per share $ 2.61 $ (2.60 ) $ 0.83 Diluted earnings (loss) per share $ 2.52 $ (2.60 ) $ 0.81 Weighted average restricted stock units and performance stock units outstanding that could be converted into approximately 327,000 and 80,000 common shares, respectively, for the year ended December 31, 2017, were not included in the computation of diluted earnings per share because the effects would be anti-dilutive.
Translation of Foreign Currencies	Translation of Foreign Currencies The Company generally designates the local currency for all its subsidiaries as the functional currency. The Company translates the assets and liabilities of its subsidiaries into U.S. dollars at the current rate of exchange prevailing at the balance sheet date. Revenue and expenses are translated at a monthly average exchange rate for the period. Translation adjustments are reported as a component of Accumulated other comprehensive income .
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted Cash The Company has lease agreements and business licenses with terms that require the Company to restrict cash through the termination dates of the agreements, which extend through 2024. Current and non-current restricted cash is included in Other current assets and Other non-current assets , respectively, on the Consolidated Balance Sheet. 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 December 31, 2018 , 2017 and 2016 : December 31, 2018 2017 2016 Cash and cash equivalents $ 279,906 $ 207,534 $ 165,011 Restricted cash included within other current assets 108 526 139 Restricted cash included within other non-current assets 248 102 420 Total cash, cash equivalents and restricted cash $ 280,262 $ 208,162 $ 165,570
Recently Issued Financial Accounting Standards	Recently Issued Financial Accounting Standards In February 2016, the Financial Accounting Standards Board ("FASB") issued ASU No. 2016-02, Leases, intended to improve financial reporting about leasing transactions. The guidance requires entities that lease assets to recognize on their balance sheets the assets and liabilities for the rights and obligations created by those leases and to disclose key information about the leasing arrangements. In July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842 (Leases), which provides narrow amendments to clarify how to apply certain aspects of the new lease standard, and ASU No. 2018-11, Targeted Improvements to Topic 842 (Leases), which provides an additional, optional transition method that allows entities to initially apply the requirements by recognizing a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. An entity that adopts this method must report comparative periods in accordance with current guidance (Topic 840). The guidance is effective for interim and annual periods beginning after December 15, 2018 with early adoption permitted. The Company will adopt the guidance on January 1, 2019 using the modified retrospective method without restatement of the prior periods. As such, prior periods will continue to be presented under the existing guidance in Topic 840. The Company is currently performing its evaluation of the guidance. The Company's lease portfolio is primarily comprised of office leases, which are currently classified as operating leases and will continue to be classified as operating leases under the new guidance. The adoption of the guidance will have a material impact on the Company's Consolidated Balance Sheets with respect to recording a right-of-use asset and lease liability for each of the Company's leases. The Company will utilize the available practical expedient to not separate the non-lease components from the lease components in its office leases. The Company is currently assessing the impact of utilizing the practical expedient, however,the use of the practical expedient will increase the total lease liability. The Company does not anticipate a significant change in expense recognition as it relates to the new guidance. Recently Adopted Financial Accounting Standards In 2018, the Company adopted ASU No. 2018-02, Income Statement - Reporting Comprehensive Income, 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. ASU 2018-02 is effective for interim and annual periods beginning after December 15, 2018, with early adoption permitted. The Company elected not to utilize the available option to reclassify stranded tax effects in accumulated other comprehensive income resulting from the Tax Cuts and Jobs Act to retained earnings. On January 1, 2018, the Company adopted ASU No. 2017-09, Compensation - Stock Compensation, Scope of Modification Accounting, which is intended to provide clarity and reduce diversity in practice, cost and complexity when implementing a change in the terms or conditions of a share-based payment award. ASU No. 2017-09 requires that an entity should account for the effects of a modification unless the fair value, vesting conditions and whether the award is classified as a liability instrument or an equity instrument remain unchanged in the modification. The adoption of this guidance did not have an impact on the Company's financial statements. The future impact of this accounting guidance will be dependent on future modification events including the number of awards modified. On January 1, 2018, the Company adopted ASU No. 2017-07, Compensation - Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post-retirement Benefit Cost, which is intended to improve the consistency, transparency and usefulness of net benefit cost disclosures. ASU No. 2017-07 requires that an employer report the service cost component of net benefit cost in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. Additionally, the other components of net benefit costs are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations. The adoption of this guidance did not have an impact on the Company's financial statements. On January 1, 2018, the Company adopted ASU No. 2016-18, Statement of Cash Flows: Restricted Cash, which requires that the statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash should be included with cash and cash equivalents when reconciling the beginning of period and end of period total amounts shown on the statement of cash flows. The adoption of this guidance increased the Company's beginning and ending balances of cash, cash equivalents and restricted cash in the Condensed Consolidated Statement of Cash Flows by approximately $0.4 million and $0.6 million, respectively for the year ended December 31, 2018. Beginning and ending balances of cash, cash equivalents and restricted cash in the Condensed Consolidated Statement of Cash Flows increased by approximately $0.6 million and $0.6 million, respectively for the year ended December 31, 2017. Beginning and ending balances of cash, cash equivalents and restricted cash in the Condensed Consolidated Statement of Cash Flows increased by approximately $7.8 million and $0.6 million, respectively for the year ended December 31, 2016. On January 1, 2018, the Company adopted ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments, which is intended to reduce diversity in practice as to how certain cash receipts and cash payments should be presented and classified. The adoption of this guidance did not have a material impact on the Company's financial statements for the years ended December 31, 2018 and 2017. For the year ended December 31, 2016, the Company reclassified approximately $2.9 million of earnout payments from cash flows used in financing activities to cash flows provided by operating activities. The reclassified amount represents the amount of the earnout payement that is in excess of the earnout accrual established at the acquisition date. On January 1, 2018, the Company adopted ASU No. 2016-01, Financial Instruments: Recognition and Measurement of Financial Assets and Financial Liabilities, which addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments including the recognition of unrealized changes in fair value within net income. The adoption of this guidance resulted in a reclassification of accumulated unrealized gains of approximately $6.1 million from accumulated other comprehensive income to retained earnings. The impact of the adoption of this guidance on the Company's Condensed Consolidated Statement of Comprehensive Income for the year ended December 31, 2018, was not material. The comparative periods have not been restated and continue to be reported under the accounting standards in effect for those periods. On January 1, 2018, the Company adopted ASU No. 2014-09, Revenue from Contracts with Customers, using the modified retrospective method. The Company applied the guidance to all contracts that were not complete as of the adoption date. The guidance requires that an entity recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the Company expects to be entitled in exchange for these goods or services. The Company recognized the cumulative effect of initially applying the new guidance as an adjustment to the opening balance of retained earnings. The comparative periods have not been restated and continue to be reported under the accounting standards in effect for those periods. See Note 3, Revenue in the Notes to Consolidated Financial Statements. Impacts on Financial Statements of Recently Adopted Financial Accounting Standards The cumulative effect of the changes made to our Condensed Consolidated Balance Sheet as of January 1, 2018, as a result of the adoption of ASU No. 2014-09, Revenue from Contracts with Customers, and ASU No. 2016-01, Financial Instruments: Recognition and Measurement of Financial Assets Financial Liabilities was as follows: December 31, ASU 2014-09 Adjustments ASU 2016-01 Adjustments January 1, Current assets Other current assets $ 11,620 $ 14,689 $ — $ 26,309 Total current assets 343,790 14,689 — 358,479 Non-current assets Deferred income taxes 35,402 (3,099 ) — 32,303 Total non-current assets 243,414 (3,099 ) — 240,315 Total assets $ 587,204 $ 11,590 $ — $ 598,794 Current liabilities Deferred revenue 31,272 (1,059 ) — 30,213 Other current liabilities 40,346 3,695 — 44,041 Total current liabilities 265,792 2,636 — 268,428 Total liabilities $ 374,499 $ 2,636 $ — $ 377,135 Stockholders' equity Retained earnings (deficit) (716 ) 8,954 6,089 14,327 Accumulated other comprehensive income 13,315 — (6,089 ) 7,226 Total stockholders’ equity 212,705 8,954 — 221,659 Total liabilities and stockholders’ equity $ 587,204 $ 11,590 $ — $ 598,794 The impact of ASU No. 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Balance Sheet as of December 31, 2018 , was as follows: December 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Current assets Other current assets $ 29,598 $ 11,461 $ 18,137 Total current assets 450,867 432,730 18,137 Non-current assets Deferred income taxes 34,830 37,929 (3,099 ) Total non-current assets 249,762 252,861 (3,099 ) Total assets $ 700,629 $ 685,591 $ 15,038 Current liabilities Accrued salaries and employee benefits 227,653 224,657 2,996 Deferred revenue 40,673 43,823 (3,150 ) Other current liabilities 33,219 28,224 4,995 Income taxes payable 8,240 7,866 374 Total current liabilities 318,951 313,736 5,215 Total liabilities $ 433,473 $ 428,258 $ 5,215 Stockholders' equity Retained earnings (deficit) 56,049 46,227 9,822 Total stockholders’ equity 267,156 257,334 9,822 Total liabilities and stockholders’ equity $ 700,629 $ 685,591 $ 15,038 The impact of ASU No. 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Comprehensive Income for the three and twelve months ended December 31, 2018 , was as follows: Three Months Ended December 31, 2018 (Unaudited) Twelve Months Ended December 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Revenue Revenue before reimbursements (net revenue) $ 185,305 $ 182,413 $ 2,892 $ 716,023 $ 711,785 $ 4,238 Reimbursements 5,662 5,662 — 19,632 19,632 — Total revenue 190,967 188,075 2,892 735,655 731,417 4,238 Operating expenses Salaries and employee benefits 133,328 131,278 2,050 506,349 503,353 2,996 General and administrative expenses 35,285 35,285 — 140,817 140,817 — Reimbursed expenses 5,662 5,662 — 19,632 19,632 — Total operating expenses 174,275 172,225 2,050 666,798 663,802 2,996 Operating income 16,692 15,850 842 68,857 67,615 1,242 Non-operating income (expense) Interest, net 645 645 — 1,141 1,141 — Other, net (1,355 ) (1,355 ) — 494 494 — Net non-operating income (expense) (710 ) (710 ) — 1,635 1,635 — Income before income taxes 15,982 15,140 842 70,492 69,250 1,242 Provision for income taxes 4,787 4,533 254 21,197 20,823 374 Net income $ 11,195 $ 10,607 $ 588 $ 49,295 $ 48,427 $ 868 Basic earnings per share $ 0.59 $ 0.56 $ 0.03 $ 2.61 $ 2.56 $ 0.05 Diluted earnings per share $ 0.58 $ 0.55 $ 0.03 $ 2.52 $ 2.48 $ 0.04 The impact of ASU 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Cash Flows for the twelve months ended December 31, 2018 , was as follows: Twelve Months Ended December 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Cash flows - operating activities Net income $ 49,295 $ 48,427 $ 868 Changes in assets and liabilities, net of effects of acquisitions: Accrued expenses 71,526 62,372 9,154 Deferred revenue (1,899 ) 3,248 (5,147 ) Income taxes payable, net 757 383 374 Other assets and liabilities, net (4,748 ) (663 ) (4,085 ) Net cash provided by operating activities $ 102,902 $ 102,902 $ —

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Summary of Estimated Useful Life of Property and Equipment	Property and Equipment Property and equipment are stated at cost. Depreciation is computed using the straight-line method over the estimated useful life of the asset or, for leasehold improvements, the shorter of the lease term or the estimated useful life of the asset, as follows: Office furniture, fixtures and equipment 5–10 years Computer equipment and software 3–7 years Leasehold improvements are depreciated over the lesser of the lease term or life of the asset improvement, which typically range from three to ten years. Depreciation is calculated for tax purposes using accelerated methods, where applicable. Property and Equipment Property and equipment are stated at cost. Depreciation is computed using the straight-line method over the estimated useful life of the asset or, for leasehold improvements, the shorter of the lease term or the estimated useful life of the asset, as follows: Office furniture, fixtures and equipment 5–10 years Computer equipment and software 3–7 years Leasehold improvements are depreciated over the lesser of the lease term or life of the asset improvement, which typically range from three to ten years. Depreciation is calculated for tax purposes using accelerated methods, where applicable.
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table sets forth the computation of basic and diluted earnings (loss) per share: December 31, 2018 2017 2016 Net income (loss) $ 49,295 $ (48,635 ) $ 15,413 Weighted average shares outstanding: Basic 18,917 18,735 18,540 Effect of dilutive securities: Restricted stock units 406 — 347 Performance stock units 209 — 151 Diluted 19,532 18,735 19,038 Basic earnings (loss) per share $ 2.61 $ (2.60 ) $ 0.83 Diluted earnings (loss) per share $ 2.52 $ (2.60 ) $ 0.81

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Effects of Account Standards Updates - Balance Sheet (Tables)	12 Months Ended
	Dec. 31, 2018
Item Effected [Line Items]
Balance Sheet Effects of Newly Adopted Accounting Pronouncements [Table Text Block]	The impact of ASU No. 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Balance Sheet as of December 31, 2018 , was as follows: December 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Current assets Other current assets $ 29,598 $ 11,461 $ 18,137 Total current assets 450,867 432,730 18,137 Non-current assets Deferred income taxes 34,830 37,929 (3,099 ) Total non-current assets 249,762 252,861 (3,099 ) Total assets $ 700,629 $ 685,591 $ 15,038 Current liabilities Accrued salaries and employee benefits 227,653 224,657 2,996 Deferred revenue 40,673 43,823 (3,150 ) Other current liabilities 33,219 28,224 4,995 Income taxes payable 8,240 7,866 374 Total current liabilities 318,951 313,736 5,215 Total liabilities $ 433,473 $ 428,258 $ 5,215 Stockholders' equity Retained earnings (deficit) 56,049 46,227 9,822 Total stockholders’ equity 267,156 257,334 9,822 Total liabilities and stockholders’ equity $ 700,629 $ 685,591 $ 15,038 The cumulative effect of the changes made to our Condensed Consolidated Balance Sheet as of January 1, 2018, as a result of the adoption of ASU No. 2014-09, Revenue from Contracts with Customers, and ASU No. 2016-01, Financial Instruments: Recognition and Measurement of Financial Assets Financial Liabilities was as follows: December 31, ASU 2014-09 Adjustments ASU 2016-01 Adjustments January 1, Current assets Other current assets $ 11,620 $ 14,689 $ — $ 26,309 Total current assets 343,790 14,689 — 358,479 Non-current assets Deferred income taxes 35,402 (3,099 ) — 32,303 Total non-current assets 243,414 (3,099 ) — 240,315 Total assets $ 587,204 $ 11,590 $ — $ 598,794 Current liabilities Deferred revenue 31,272 (1,059 ) — 30,213 Other current liabilities 40,346 3,695 — 44,041 Total current liabilities 265,792 2,636 — 268,428 Total liabilities $ 374,499 $ 2,636 $ — $ 377,135 Stockholders' equity Retained earnings (deficit) (716 ) 8,954 6,089 14,327 Accumulated other comprehensive income 13,315 — (6,089 ) 7,226 Total stockholders’ equity 212,705 8,954 — 221,659 Total liabilities and stockholders’ equity $ 587,204 $ 11,590 $ — $ 598,794

Summary of Significant Accoun_5

Summary of Significant Accounting Policies Effects of Accounting Standards Updates - Income Statement (Tables)	12 Months Ended
	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income Statement Effects of ASU 2014-09 [Table Text Block]	The impact of ASU No. 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Comprehensive Income for the three and twelve months ended December 31, 2018 , was as follows: Three Months Ended December 31, 2018 (Unaudited) Twelve Months Ended December 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Revenue Revenue before reimbursements (net revenue) $ 185,305 $ 182,413 $ 2,892 $ 716,023 $ 711,785 $ 4,238 Reimbursements 5,662 5,662 — 19,632 19,632 — Total revenue 190,967 188,075 2,892 735,655 731,417 4,238 Operating expenses Salaries and employee benefits 133,328 131,278 2,050 506,349 503,353 2,996 General and administrative expenses 35,285 35,285 — 140,817 140,817 — Reimbursed expenses 5,662 5,662 — 19,632 19,632 — Total operating expenses 174,275 172,225 2,050 666,798 663,802 2,996 Operating income 16,692 15,850 842 68,857 67,615 1,242 Non-operating income (expense) Interest, net 645 645 — 1,141 1,141 — Other, net (1,355 ) (1,355 ) — 494 494 — Net non-operating income (expense) (710 ) (710 ) — 1,635 1,635 — Income before income taxes 15,982 15,140 842 70,492 69,250 1,242 Provision for income taxes 4,787 4,533 254 21,197 20,823 374 Net income $ 11,195 $ 10,607 $ 588 $ 49,295 $ 48,427 $ 868 Basic earnings per share $ 0.59 $ 0.56 $ 0.03 $ 2.61 $ 2.56 $ 0.05 Diluted earnings per share $ 0.58 $ 0.55 $ 0.03 $ 2.52 $ 2.48 $ 0.04

Summary of Significant Accoun_6

Summary of Significant Accounting Policies Effects of Accounting Standards Updates - Cash Flow (Tables)	12 Months Ended
	Dec. 31, 2018
Cash Flow Effects of ASU 2014-09 [Line Items]
Cash Flow Effects of ASU 2014-09 [Table Text Block]	The impact of ASU 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Cash Flows for the twelve months ended December 31, 2018 , was as follows: Twelve Months Ended December 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Cash flows - operating activities Net income $ 49,295 $ 48,427 $ 868 Changes in assets and liabilities, net of effects of acquisitions: Accrued expenses 71,526 62,372 9,154 Deferred revenue (1,899 ) 3,248 (5,147 ) Income taxes payable, net 757 383 374 Other assets and liabilities, net (4,748 ) (663 ) (4,085 ) Net cash provided by operating activities $ 102,902 $ 102,902 $ —

Summary of Significant Accoun_7

Summary of Significant Accounting Policies Cash and Cash Equivalents, Restricted Cash and Cash Equivalents (Tables)	12 Months Ended
	Dec. 31, 2018
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted Cash The Company has lease agreements and business licenses with terms that require the Company to restrict cash through the termination dates of the agreements, which extend through 2024. Current and non-current restricted cash is included in Other current assets and Other non-current assets , respectively, on the Consolidated Balance Sheet. 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 December 31, 2018 , 2017 and 2016 : December 31, 2018 2017 2016 Cash and cash equivalents $ 279,906 $ 207,534 $ 165,011 Restricted cash included within other current assets 108 526 139 Restricted cash included within other non-current assets 248 102 420 Total cash, cash equivalents and restricted cash $ 280,262 $ 208,162 $ 165,570

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2018
Unbilled Receivables, Contract Assets and Liabilities [Line Items]
Unbilled Receivables, Contract Assets and Liabilities [Table Text Block]	he following table outlines the changes in our contract asset and liability balances during the period: January 1, December 31, Variance Contract assets Unbilled receivables $ 5,487 $ 8,684 $ 3,197 Contract assets 12,398 15,291 2,893 Contract liabilities Deferred revenue $ 30,213 $ 40,673 $ 10,460

Allowance for Doubtful Accoun_2

Allowance for Doubtful Accounts (Tables)	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Summary of Allowance for Doubtful Accounts	The activity of the allowance for doubtful accounts for the years ended: December 31, 2018 2017 2016 Balance at January 1, $ 2,534 $ 2,575 $ 5,376 Provision charged to income 3,790 963 1,407 Write-offs (2,708 ) (1,134 ) (4,106 ) Foreign currency translation (114 ) 130 (102 ) Balance at December 31, $ 3,502 $ 2,534 $ 2,575

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Components of Company's Property and Equipment	The components of the Company’s property and equipment are as follows: December 31, 2018 2017 Leasehold improvements $ 48,455 $ 48,216 Office furniture, fixtures and equipment 17,919 17,732 Computer equipment and software 27,063 28,300 Property and equipment, gross 93,437 94,248 Accumulated depreciation (59,566 ) (54,734 ) Property and equipment, net $ 33,871 $ 39,514

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Levels of Inputs Used to Measure Fair Value of Assets	Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total At December 31, 2018 U.S. non-qualified deferred compensation plan $ 19,442 $ — $ — $ 19,442 Assets designated for retirement and pension plans — 16,384 — 16,384 Pension benefit obligation — (20,908 ) — (20,908 ) Acquisition earnout accruals — — (6,627 ) (6,627 ) $ 19,442 $ (4,524 ) $ (6,627 ) $ 8,291 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total At December 31, 2017 U.S. non-qualified deferred compensation plan $ 21,319 $ — $ — $ 21,319 Assets designated for retirement and pension plans — 18,590 — 18,590 Pension benefit obligation — (23,886 ) — (23,886 ) Acquisition earnout accruals — — (7,213 ) (7,213 ) $ 21,319 $ (5,296 ) $ (7,213 ) $ 8,810
Reconciliation of Beginning and Ending Balance of Level 3 Assets and Liabilities	The following table provides a reconciliation of the beginning and ending balance of Level 3 liabilities for the year ended December 31, 2018 : Acquisition Balance at December 31, 2017 $ (7,213 ) Acquisition earnouts (Note 8) (3,054 ) Earnout accretion (1,285 ) Earnout payments 3,592 Earnout adjustment (1) 888 Foreign currency translation 445 Balance at December 31, 2018 $ (6,627 )

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
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 December 31, 2018 for the years ended December 31st is as follows: 2019 $ 846 2020 529 2021 356 2022 241 2023 147 Thereafter 97 Total $ 2,216
Goodwill by Segment [Table Text Block]	The Company's goodwill by segment is as follows: December 31, 2018 December 31, 2017 Executive Search Americas $ 88,410 $ 88,690 Europe 24,924 20,900 Asia Pacific 8,758 9,302 Total Executive Search 122,092 118,892 Heidrick Consulting 36,257 36,257 Goodwill, gross 158,349 155,149 Accumulated impairment (36,257 ) (36,257 ) Goodwill, net $ 122,092 $ 118,892
Changes in Carrying Amount of Goodwill by Segment	Changes in the carrying amount of goodwill by segment for the years ended December 31, 2018 , 2017 , and 2016 were as follows: Executive Search Americas Europe Asia Pacific Heidrick Consulting Total Balance at December 31, 2015 $ 81,626 $ 10,745 $ 9,211 $ 29,540 $ 131,122 DSI acquisition 5,673 — — — 5,673 Philosophy IB acquisition 2,357 — — — 2,357 JCA Group acquisition — 15,769 — — 15,769 Segment reallocation (1) (1,670 ) (4,517 ) (347 ) 6,534 — Exchange rate fluctuations 115 (2,905 ) 29 (316 ) (3,077 ) Balance at December 31, 2016 88,101 19,092 8,893 35,758 151,844 Philosophy IB acquisition 357 — — 7 364 Exchange rate fluctuations 232 1,808 409 492 2,941 Impairment — — — (36,257 ) (36,257 ) Balance at December 31, 2017 88,690 20,900 9,302 — 118,892 Amrop acquisition — 5,478 — — 5,478 Foreign currency translation (280 ) (1,454 ) (544 ) — (2,278 ) Balance at December 31, 2018 $ 88,410 $ 24,924 $ 8,758 $ — $ 122,092 (1) Due to the Company's change in segment reporting during the year ended December 31, 2016, goodwill amounts included in the Company's Americas, Europe and Asia Pacific segments in the prior year have been reallocated to the Heidrick Consulting segment utilizing the relative fair value method.
Carrying Amount of Amortizable Intangible Assets and Related Accumulated Amortization	The carrying amount of amortizable intangible assets and the related accumulated amortization were as follows: December 31, 2018 December 31, 2017 Weighted Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Carrying Amount Client relationships 6.8 $ 15,910 $ (13,694 ) $ 2,216 $ 13,703 $ (11,612 ) $ 2,091 Trade name 0.0 434 (434 ) — 459 (459 ) — Non-compete 0.0 217 (217 ) — 230 (163 ) 67 Total intangible assets 6.8 $ 16,561 $ (14,345 ) $ 2,216 $ 14,392 $ (12,234 ) $ 2,158

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets Schedule of Finite Lived Intangible Assets by Segment (Tables)	12 Months Ended
	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Schedule Of Finite Lived Intangible Assets By Segment [Table Text Block]	The Company’s other intangible assets, net by segment, are as follows: December 31, 2018 December 31, 2017 Executive Search Americas $ 52 $ 252 Europe 2,086 1,799 Asia Pacific 78 107 Total Executive Search 2,216 2,158 Heidrick Consulting — — Total Other Intangible Assets, Net $ 2,216 $ 2,158

Other Non-Current Liabilities (

Other Non-Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Components of Other Non-Current Liabilities	The components of other non-current liabilities are as follows: December 31, 2018 December 31, 2017 Premise related costs $ 15,473 $ 18,360 Accrued earnout payments — 3,076 Restructuring charges — 10 Other 1,950 2,151 Total other non-current liabilities $ 17,423 $ 23,597

Other Current Assets and Liab_2

Other Current Assets and Liabilities and Non-Current Liabilities Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Other Current Liabilities [Line Items]
Other Current Liabilities [Table Text Block]	The components of other current liabilities are as follows: December 31, 2018 December 31, 2017 Restructuring charges $ 1,287 $ 13,023 Other 31,932 27,323 Total other current liabilities $ 33,219 $ 40,346

Other Current Assets and Liab_3

Other Current Assets and Liabilities and Non-Current Liabilities Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Other Current Assets - Components of Other Current Assets [Line Items]
Other Current Assets [Text Block]	The components of other current assets are as follows: December 31, 2018 December 31, 2017 Contract assets $ 23,975 $ 3,538 Other 5,623 8,082 Total other current assets $ 29,598 $ 11,620

Pension Plan and Life Insuran_2

Pension Plan and Life Insurance Contract (Tables)	12 Months Ended
	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Schedule of Changes in Projected Benefit Obligations [Table Text Block]	2018 2017 Benefit obligation at January 1, $ 23,886 $ 22,128 Interest cost 373 362 Actuarial (gain) loss (886 ) (371 ) Benefits paid (1,450 ) (1,453 ) Cumulative translation adjustment (1,015 ) 3,220 Benefit obligation at December 31, $ 20,908 $ 23,886
Schedule of Net Benefit Costs [Table Text Block]	The components of and assumptions used to determine the net periodic benefit cost are as follows: December 31, 2018 2017 2016 Net period benefit cost: Interest cost $ 373 $ 362 $ 453 Amortization of net loss 92 111 17 Net periodic benefit cost $ 465 $ 473 $ 470 Weighted average assumptions Discount rate (1) 1.64 % 1.49 % 2.15 % Rate of compensation increase — % — % — %
Schedule of Assumptions Used [Table Text Block]	Assumptions to determine the Company’s benefit obligation are as follows: December 31, 2018 2017 2016 Discount rate (1) 1.71 % 1.64 % 1.53 % Rate of compensation increase — % — % — % Measurement Date 12/31/2018 12/31/2017 12/31/2016
Schedule of Expected Benefit Payments [Table Text Block]	The benefits expected to be paid in each of the next five years, and in the aggregate for the five years thereafter are as follows: 2019 $ 1,349 2020 1,339 2021 1,326 2022 1,309 2023 1,289 2024 through 2028 6,001
Schedule of Amounts Recognized in Balance Sheet [Table Text Block]	The benefit obligation amounts recognized in the Consolidated Balance Sheets are as follows: December 31, 2018 2017 Current liabilities $ 1,349 $ 1,461 Noncurrent liabilities 19,559 22,425 Total $ 20,908 $ 23,886

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Information with Respect to Stock-based Compensation	A summary of information with respect to stock-based compensation is as follows: December 31, 2018 2017 2016 Salaries and employee benefits (1) $ 9,548 $ 4,597 $ 5,830 General and administrative expenses 562 338 563 Income tax benefit related to stock-based compensation included in net income 2,674 1,948 2,523
Restricted Stock Unit Activity	Restricted stock unit activity as of December 31, 2018 , 2017 and 2016 is as follows: Number of Weighted- Outstanding on December 31, 2015 473,935 $ 19.98 Granted 207,405 22.92 Vested and converted to common stock (119,455 ) 20.02 Forfeited (24,612 ) 22.81 Outstanding on December 31, 2016 537,273 20.97 Granted 243,306 24.18 Vested and converted to common stock (217,028 ) 21.39 Forfeited (72,397 ) 24.05 Outstanding on December 31, 2017 491,154 21.92 Granted 297,664 34.64 Vested and converted to common stock (199,550 ) 21.66 Forfeited (76,822 ) 25.76 Outstanding on December 31, 2018 512,446 28.83
Performance Stock Unit Activity	Performance share unit activity as of December 31, 2018 , 2017 and 2016 is as follows: Number of Weighted- Outstanding on December 31, 2015 272,024 $ 18.28 Granted 125,388 22.98 Vested and converted to common stock (160,600 ) 15.51 Forfeited — — Outstanding on December 31, 2016 236,812 22.64 Granted 88,415 23.83 Vested and converted to common stock (70,652 ) 19.65 Forfeited (68,684 ) 24.07 Outstanding on December 31, 2017 185,891 23.82 Granted 102,138 25.81 Vested and converted to common stock (43,361 ) 23.64 Forfeited (47,551 ) 23.87 Outstanding on December 31, 2018 197,117 24.88

Stock-Based Compensation Schedu

Stock-Based Compensation Schedule of Share-based Compensation, Phantom Stock Units Award Activity (Tables)	12 Months Ended
	Dec. 31, 2018
Schedule of Share-based Compensation, Phantom Stock Units Award Activity [Line Items]
Schedule of Share-based Compensation, Phantom Stock Units Award Activity [Table Text Block]	Phantom stock unit activity as of December 31, 2018 is as follows: Number of Stock Units Outstanding on December 31, 2017 — Granted 111,673 Vested — Forfeited — Outstanding on December 31, 2018 111,673

Changes in Accumulated Other _2

Changes in Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Changes in Accumulated Other Comprehensive Income ("AOCI") by Component	The changes in Accumulated other comprehensive income (“AOCI”) by component for the year ended December 31, 2018 , are summarized below: Available- Foreign Pension AOCI Balance at December 31, 2017 $ 6,089 $ 9,143 $ (1,917 ) $ 13,315 Other comprehensive income before classification, net of tax — (3,885 ) 721 (3,164 ) Amount reclassified from AOCI — — — — Net current period other comprehensive income — (3,885 ) 721 (3,164 ) Adoption of accounting standards (1) (6,089 ) — — (6,089 ) Balance at December 31, 2018 — $ 5,258 $ (1,196 ) $ 4,062 (1) Upon adoption of ASC 2016-01, unrealized gains (losses) on available for sale securities were reclassified from AOCI to retained earnings

Restructuring Schedule of Restr

Restructuring Schedule of Restructuring Charges by Segment (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Restructuring Charges by Segment [Line Items]
Schedule of Restructuring Charges by Segment [Table Text Block]	Restructuring charges by operating segment for the year ended December 31, 2017, are as follows: Restructuring Charges Executive Search Americas $ 784 Europe 3,993 Asia Pacific 2,046 Total Executive Search 6,823 Heidrick Consulting 3,393 Global Operations Support 5,450 Total restructuring $ 15,666

Restructuring Schedule of Res_2

Restructuring Schedule of Restructuring Charges and Related Cash Payments (Tables)	12 Months Ended
	Dec. 31, 2018
Schedule of Restructuring Charges and Related Cash Payments [Line Items]
Schedule of Restructuring Charges and Related Cash Payments [Table Text Block]	The accrued restructuring charges at December 31, 2018 , primarily consists of employee-related costs that require cash payments based on individual severance agreements. These accruals are included within Other current liabilities in the Consolidated Balance Sheets at December 31, 2018 . The table below outlines the restructuring charges along with related cash payments for the years ended December 31, 2018 and 2017 : Employee Related Office Related Other Total Accrual balance at December 31, 2016 $ — $ — $ — $ — Restructuring charges 13,065 308 2,293 15,666 Cash payments (1,199 ) (5 ) (1,282 ) (2,486 ) Non cash write-offs — (155 ) — (155 ) Accrual balance at December 31, 2017 $ 11,866 $ 148 $ 1,011 $ 13,025 Cash payments (8,689 ) (248 ) (993 ) (9,930 ) Non cash write-offs — 195 — 195 Other (1,843 ) (95 ) 5 (1,933 ) Exchange rate fluctuations (65 ) — (6 ) (71 ) Accrual balance at December 31, 2018 $ 1,269 $ — $ 17 $ 1,286

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Sources of Income (Loss) before Income Taxes	The sources of income (loss) before income taxes are as follows: December 31, 2018 2017 2016 United States $ 47,191 $ (28,577 ) $ 30,696 Foreign 23,301 (841 ) 7,070 Income (loss) before income taxes $ 70,492 $ (29,418 ) $ 37,766
Provision for (Benefit from) Income Taxes	The provision for (benefit from) income taxes are as follows: December 31, 2018 2017 2016 Current Federal $ 12,311 $ 10,107 $ 12,261 State and local 4,843 2,372 3,219 Foreign 6,907 8,257 5,668 Current provision for income taxes 24,061 20,736 21,148 Deferred Federal 6,403 5,642 727 State and local (354 ) (2,951 ) (370 ) Foreign (8,913 ) (4,210 ) 848 Deferred provision (benefit) for income taxes (2,864 ) (1,519 ) 1,205 Total provision for income taxes $ 21,197 $ 19,217 $ 22,353
Reconciliation of Provision for (Benefit from) Income Taxes	A reconciliation of the provision for income taxes to income taxes at the statutory U.S. federal income tax rate of 21% is as follows: December 31, 2018 2017 2016 Income tax provision (benefit) at the statutory U.S. federal rate $ 14,803 $ (10,296 ) $ 13,218 State income tax provision (benefit), net of federal tax benefit 3,242 (593 ) 1,904 Nondeductible expenses, net 2,587 3,282 1,410 Foreign taxes (includes rate differential and changes in foreign valuation allowance) (35 ) 5,465 (2,133 ) Establishment (release) of valuation allowance (43 ) (3,200 ) 340 U.S. tax on foreign dividends 765 — 5,898 Current/deferred true-up (1,199 ) 567 1,226 Tax reform — 23,732 — Other, net 1,077 260 490 Total provision for income taxes $ 21,197 $ 19,217 $ 22,353
Summary of Deferred Tax Assets and Liabilities	The deferred tax assets and liabilities are attributable to the following components: December 31, 2018 2017 Deferred tax assets attributable to: Foreign net operating loss carryforwards $ 18,259 $ 31,960 Accrued compensation and employee benefits 15,442 15,809 Deferred compensation 15,587 13,600 Foreign tax credit carryforwards 8,163 8,128 Accrued rent 3,096 3,607 Other accrued expenses 6,290 2,179 Deferred tax assets, before valuation allowance 66,837 75,283 Valuation allowance (26,460 ) (35,624 ) Deferred tax assets, after valuation allowance 40,377 39,659 Deferred tax liabilities attributable to: Goodwill 2,203 306 Taxes provided on unremitted earnings 765 129 Depreciation on property and equipment 2,040 3,216 Other 686 606 Deferred tax liabilities 5,694 4,257 Net deferred tax assets $ 34,683 $ 35,402
Reconciliation of Amounts of Gross Unrecognized Tax Benefits	A reconciliation of the beginning and ending balances of the total amounts of gross unrecognized tax benefits is as follows: December 31, 2018 2017 2016 Gross unrecognized tax benefits at January 1, $ 740 $ 1,038 $ 130 Gross increases for tax positions of prior years 608 167 2,146 Gross decreases for tax positions of prior years — — (4 ) Settlements (220 ) (465 ) (1,234 ) Lapse of statute of limitations — — — Gross unrecognized tax benefits at December 31, $ 1,128 $ 740 $ 1,038

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenue, Operating Income, Depreciation and Amortization, and Capital Expenditures, by Segment	The revenue, operating income, depreciation and amortization, and capital expenditures, by segment, are as follows: December 31, 2018 2017 2016 Revenue Executive Search Americas $ 405,267 $ 339,793 $ 313,292 Europe 145,348 125,346 108,754 Asia Pacific 102,276 86,905 85,319 Total Executive Search 652,891 552,044 507,365 Heidrick Consulting 63,132 69,356 75,025 Revenue before reimbursements 716,023 621,400 582,390 Reimbursements 19,632 18,656 18,516 Total revenue $ 735,655 $ 640,056 $ 600,906 Operating Income (Loss) Executive Search Americas (1) $ 96,880 $ 75,337 $ 71,993 Europe (2) 5,849 13 5,943 Asia Pacific (3) 15,999 537 3,944 Total Executive Search 118,728 75,887 81,880 Heidrick Consulting (4) (13,619 ) (62,368 ) (5,322 ) Total segments 105,109 13,519 76,558 Global Operations Support (5) (36,252 ) (40,042 ) (41,325 ) Total operating income (loss) $ 68,857 $ (26,523 ) $ 35,233 Depreciation and Amortization Executive Search Americas $ 4,605 $ 4,794 $ 3,892 Europe 3,735 3,328 2,478 Asia Pacific 1,646 1,565 1,774 Total Executive Search 9,986 9,687 8,144 Heidrick Consulting 1,577 4,099 6,842 Total segments 11,563 13,786 14,986 Global Operations Support 959 988 1,447 Total depreciation and amortization $ 12,522 $ 14,774 $ 16,433 Capital Expenditures Executive Search Americas $ 601 $ 7,123 $ 2,221 Europe 3,557 1,460 835 Asia Pacific 440 2,633 3,346 Total Executive Search 4,598 11,216 6,402 Heidrick Consulting 581 1,172 659 Total segments 5,179 12,388 7,061 Global Operations Support 1,006 3,298 1,321 Total capital expenditures $ 6,185 $ 15,686 $ 8,382 (1) Operating income for the Americas includes $0.8 million of restructuring charges in 2017. (2) Operating income for Europe includes $4.0 million of restructuring charges in 2017. (3) Operating income for Asia Pacific includes $2.0 million of restructuring charges in 2017. (4) Operating loss for Heidrick Consulting includes $50.7 million of impairment charges and $3.4 million of restructuring charges in 2017. (5) Operating loss for Global Operations Support includes $5.5 million of restructuring charges in 2017.
Identifiable Assets, Goodwill and Other Intangible Assets, Net, by Segment	Identifiable assets, and goodwill and other intangible assets, net, by segment, are as follows: December 31, 2018 2017 Current assets Executive Search Americas $ 255,889 $ 171,985 Europe 85,355 84,405 Asia Pacific 74,169 55,196 Total Executive Search 415,413 311,586 Heidrick Consulting 34,174 31,116 Total segments 449,587 342,702 Global Operations Support 1,280 1,088 Total allocated current assets 450,867 343,790 Unallocated non-current assets 125,454 122,364 Goodwill and other intangible assets, net Executive Search Americas 88,462 88,942 Europe 27,010 22,699 Asia Pacific 8,836 9,409 Total Executive Search 124,308 121,050 Heidrick Consulting — — Total goodwill and other intangible assets, net 124,308 121,050 Total assets $ 700,629 $ 587,204

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Summary of Minimum Future Office Space and Equipment Lease Payments Due	Minimum future operating lease payments due in each of the next five years and thereafter are as follows: 2019 $ 34,456 2020 31,808 2021 27,381 2022 23,445 2023 20,087 Thereafter 14,448 Total $ 151,625

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018
Estimated Useful Lives of Property Plant & Equipment [Line Items]
Additional Vesting Period After Deferral Date For Bonus Payment	3 years
Concentration Risk, Customer	0

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Summary of Estimated Useful Life of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2017
Office Furniture, Fixtures and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	5 years
Office Furniture, Fixtures and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	10 years
Computer Equipment and Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	3 years
Computer Equipment and Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	7 years
Leasehold Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	3 years
Leasehold Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life of assets	10 years

Summary of Significant Accou_10

Summary of Significant Accounting Policies Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Attributable to Parent	$ 11,195	$ 49,295	$ (48,635)	$ 15,413
Weighted Average Number of Shares Outstanding, Basic		18,917	18,735	18,540
Weighted Average Number of Shares Outstanding, Diluted		19,532	18,735	19,038
Earnings Per Share, Basic	$ 0.59	$ 2.61	$ (2.60)	$ 0.83
Earnings Per Share, Diluted	$ 0.58	$ 2.52	$ (2.60)	$ 0.81
Restricted Stock Units (RSUs) [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements			327
Weighted Average Number of Shares Outstanding, Diluted		406	0	347
Performance Shares [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements			80
Weighted Average Number of Shares Outstanding, Diluted		209	0	151

Summary of Significant Accou_11

Summary of Significant Accounting Policies Restricted Cash (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restricted Cash and Cash Equivalents Items [Line Items]
Cash And Cash Equivalents Maximum Maturity Period	3 months
Cash and Cash Equivalents, at Carrying Value	$ 279,906	$ 207,534	$ 165,011
Restricted Cash Included with Current Assets	108	526	139
Restricted Cash Included with Non-Current Assets	248	102	420
Total Cash, Cash Equivalents, and Restricted Cash	$ 280,262	$ 208,162	$ 165,570

Summary of Significant Accou_12

Summary of Significant Accounting Policies Balance Sheet Effect of Newly Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Balance Sheet Effects of Newly Adopted Accounting Pronouncements [Line Items]
Other Assets, Current	$ 29,598	$ 26,309	$ 11,620
Assets, Current	450,867	358,479	343,790
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	34,830	32,303	35,402
Assets, Noncurrent	249,762	240,315	243,414
Assets	700,629	598,794	587,204
Employee-related Liabilities, Current	227,653		177,426
Deferred Revenue, Current	40,673	30,213	31,272
Other Liabilities, Current	33,219	44,041	40,346
Accrued Income Taxes, Current	8,240		6,924
Liabilities, Current	318,951	268,428	265,792
Liabilities	433,473	377,135	374,499
Retained Earnings (Accumulated Deficit)	56,049	14,327	(716)
Accumulated Other Comprehensive Income (Loss), Net of Tax	4,062	7,226	13,315
Stockholders' Equity Attributable to Parent	267,156	221,659	212,705	$ 258,590	$ 254,802
Liabilities and Equity	700,629	598,794	$ 587,204
Accounting Standards Update 2014-09 [Member]
Balance Sheet Effects of Newly Adopted Accounting Pronouncements [Line Items]
Other Assets, Current	18,137	14,689
Assets, Current	18,137	14,689
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent		(3,099)
Deferred Tax Assets, Net, Noncurrent	(3,099)
Assets, Noncurrent	(3,099)	(3,099)
Assets	15,038	11,590
Employee-related Liabilities, Current	2,996
Deferred Revenue, Current	(3,150)	(1,059)
Other Liabilities, Current	4,995	3,695
Accrued Income Taxes, Current	374
Liabilities, Current	5,215	2,636
Liabilities	5,215	2,636
Retained Earnings (Accumulated Deficit)	9,822	8,954
Accumulated Other Comprehensive Income (Loss), Net of Tax		0
Stockholders' Equity Attributable to Parent	9,822	8,954
Liabilities and Equity	15,038	11,590
Accounting Standards Update 2016-01 [Member]
Balance Sheet Effects of Newly Adopted Accounting Pronouncements [Line Items]
Other Assets, Current		0
Assets, Current		0
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent		0
Assets, Noncurrent		0
Assets		0
Deferred Revenue, Current		0
Other Liabilities, Current		0
Liabilities, Current		0
Liabilities		0
Retained Earnings (Accumulated Deficit)		6,089
Accumulated Other Comprehensive Income (Loss), Net of Tax		(6,089)
Stockholders' Equity Attributable to Parent		0
Liabilities and Equity		$ 0
Accounting Standards Update 2014-09 [Member]
Balance Sheet Effects of Newly Adopted Accounting Pronouncements [Line Items]
Other Assets, Current	11,461
Assets, Current	432,730
Deferred Tax Assets, Net, Noncurrent	37,929
Assets, Noncurrent	252,861
Assets	685,591
Employee-related Liabilities, Current	224,657
Deferred Revenue, Current	43,823
Other Liabilities, Current	28,224
Accrued Income Taxes, Current	7,866
Liabilities, Current	313,736
Liabilities	428,258
Retained Earnings (Accumulated Deficit)	46,227
Stockholders' Equity Attributable to Parent	257,334
Liabilities and Equity	$ 685,591

Summary of Significant Accou_13

Summary of Significant Accounting Policies Income Statement Effects of Newly Adopted Accounting Pronouncements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Item Effected [Line Items]
Sales Revenue, Services, Net	$ 185,305	$ 716,023	$ 621,400	$ 582,390
Reimbursement Revenue	5,662	19,632	18,656	18,516
Revenues	190,967	735,655	640,056	600,906
Labor and Related Expense	133,328	506,349	434,219	400,070
General And Administrative Excluding Labor And Related Expense	35,285	140,817
Cost of Reimbursable Expense	5,662	19,632	18,656	18,516
Operating Expenses	174,275	666,798	666,579	565,673
Operating Income (Loss)	16,692	68,857	(26,523)	35,233
Interest Income (Expense), Net	645	1,141	385	244
Other Nonoperating Income (Expense)	(1,355)	494	(3,280)	2,289
Nonoperating Income (Expense)	(710)	1,635	(2,895)	2,533
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	15,982	70,492
Income Tax Expense (Benefit)	4,787	21,197	19,217	22,353
Net Income (Loss) Attributable to Parent	$ 11,195	$ 49,295	$ (48,635)	$ 15,413
Earnings Per Share, Basic	$ 0.59	$ 2.61	$ (2.60)	$ 0.83
Earnings Per Share, Diluted	$ 0.58	$ 2.52	$ (2.60)	$ 0.81
Accounting Standards Update 2014-09 [Member]
Item Effected [Line Items]
Sales Revenue, Services, Net	$ 2,892	$ 4,238
Reimbursement Revenue	0	0
Revenues	2,892	4,238
Labor and Related Expense	2,050	2,996
General And Administrative Excluding Labor And Related Expense	0	0
Cost of Reimbursable Expense	0	0
Operating Expenses	2,050	2,996
Operating Income (Loss)	842	1,242
Interest Income (Expense), Net	0	0
Other Nonoperating Income (Expense)	0	0
Nonoperating Income (Expense)	0	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	842	1,242
Income Tax Expense (Benefit)	254	374
Net Income (Loss) Attributable to Parent	$ 588	$ 868
Earnings Per Share, Basic	$ 0.03	$ 0.05
Earnings Per Share, Diluted	$ 0.03	$ 0.04
Accounting Standards Update 2014-09 [Member]
Item Effected [Line Items]
Sales Revenue, Services, Net	$ 182,413	$ 711,785
Reimbursement Revenue	5,662	19,632
Revenues	188,075	731,417
Labor and Related Expense	131,278	503,353
General And Administrative Excluding Labor And Related Expense	35,285	140,817
Cost of Reimbursable Expense	5,662	19,632
Operating Expenses	172,225	663,802
Operating Income (Loss)	15,850	67,615
Interest Income (Expense), Net	645	1,141
Other Nonoperating Income (Expense)	(1,355)	494
Nonoperating Income (Expense)	(710)	1,635
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	15,140	69,250
Income Tax Expense (Benefit)	4,533	20,823
Net Income (Loss) Attributable to Parent	$ 10,607	$ 48,427
Earnings Per Share, Basic	$ 0.56	$ 2.56
Earnings Per Share, Diluted	$ 0.55	$ 2.48

Summary of Significant Accou_14

Summary of Significant Accounting Policies Cash Flow Effect of Newly Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flow Effects of ASU 2014-09 [Line Items]
Net Income (Loss) Attributable to Parent	$ 11,195	$ 49,295	$ (48,635)	$ 15,413
Increase (Decrease) in Accrued Liabilities		71,526	18,330	(3,808)
Increase (Decrease) in Deferred Revenue		(1,899)	2,010	(1,672)
Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable		757	3,381	1,184
Increase (Decrease) in Other Operating Assets and Liabilities, Net		(4,748)	$ 5,626	$ (3,449)
Net Cash Provided by (Used in) Operating Activities		102,902
Accounting Standards Update 2014-09 [Member]
Cash Flow Effects of ASU 2014-09 [Line Items]
Net Income (Loss) Attributable to Parent	10,607	48,427
Increase (Decrease) in Accrued Liabilities		62,372
Increase (Decrease) in Deferred Revenue		3,248
Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable		383
Increase (Decrease) in Other Operating Assets and Liabilities, Net		(663)
Net Cash Provided by (Used in) Operating Activities		102,902
Accounting Standards Update 2014-09 [Member]
Cash Flow Effects of ASU 2014-09 [Line Items]
Net Income (Loss) Attributable to Parent	$ 588	868
Increase (Decrease) in Accrued Liabilities		9,154
Increase (Decrease) in Deferred Revenue		(5,147)
Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable		374
Increase (Decrease) in Other Operating Assets and Liabilities, Net		(4,085)
Net Cash Provided by (Used in) Operating Activities		$ 0

Summary of Significant Accou_15

Summary of Significant Accounting Policies Summary of Significant Accounting Policies - Salaries and Employee Benefits (Details)	12 Months Ended
	Dec. 31, 2018
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Vesting Period Of Deferred Cash Bonuses	3 years
Maximum [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Variation Percentage Of Deferred Cash Bonuses	15.00%

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Unbilled Receivables, Contract Assets and Liabilities [Line Items]
Deferred Revenue, Revenue Recognized	$ 28,000
Unbilled Contracts Receivable	$ 8,684	$ 5,487
Percentage Of Estimated First Year Compensation Received For Executive Search Services	33.33%
Percentage Of Excess Of Actual Over Estimated Compensation Of Placed Candidate Billed To Client	33.33%
Percentage Increments Billed To Clients For Retainer And Indirect Expenses	33.33%
Increase (Decrease) in Unbilled Contracts Receivable	$ 3,197
Contract Assets	15,291	12,398
Increase (Decrease) in Contract Assets	2,893
Deferred Revenue		30,213
Deferred Revenue, Current	40,673	$ 30,213	$ 31,272
Increase (Decrease) in Contract Liabilities	10,460
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 21,800

Allowance for Doubtful Accoun_3

Allowance for Doubtful Accounts - Summary of Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning balance	$ 2,534	$ 2,575	$ 5,376
Provision charged to income	3,790	963	1,407
Write-offs	(2,708)	(1,134)	(4,106)
Foreign currency translation	114	(130)	102
Ending balance	$ 3,502	$ 2,534	$ 2,575

Property and Equipment, Net - C

Property and Equipment, Net - Components of Company's Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 93,437	$ 94,248
Accumulated depreciation	(59,566)	(54,734)
Property and equipment, net	33,871	39,514
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	48,455	48,216
Office Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	17,919	17,732
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 27,063	$ 28,300

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 11	$ 10.4	$ 9.4

Fair Value Measurements - Level

Fair Value Measurements - Levels of Inputs Used to Measure Fair Value of Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets designated for retirement and pension plans	$ 16,384	$ 18,590
Defined Benefit Plan, Benefit Obligation	(20,908)	(23,886)	$ (22,128)
Acquisition earnout accruals	(6,627)	(7,213)
Fair Value, Net Asset (Liability)	8,291	8,810
U.S. Non-Qualified Deferred Compensation Plan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	19,442	21,319
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Net Asset (Liability)	19,442	21,319
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Non-Qualified Deferred Compensation Plan [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	19,442	21,319
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	16,384	18,590
Defined Benefit Plan, Benefit Obligation	(20,908)	(23,886)
Fair Value, Net Asset (Liability)	(4,524)	(5,296)
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition earnout accruals	(6,627)	(7,213)
Fair Value, Net Asset (Liability)	$ (6,627)	$ (7,213)

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Beginning and Ending Balance of Level 3 Assets and Liabilities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Acquisition earnout accruals, beginning balance	$ (7,213)
Acquisition earnout accruals, ending balance	(6,627)
Fair Value, Inputs, Level 3 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Acquisition earnout accruals, beginning balance	(7,213)
Acquisition earnout	(3,054)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Business Combination, Acquisition Earnout Adjustment, Fair Value	888
Earnout accretion	(1,285)
Earnout payments	3,592
Foreign currency translation	445
Acquisition earnout accruals, ending balance	$ (6,627)

Investments - Additional Inform

Investments - Additional Information (Detail) - U.S. Non-Qualified Deferred Compensation Plan [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Aggregate cost basis for investments	$ 14.6	$ 14.6
Fair Value, Inputs, Level 1 [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Long-term Investments	$ 19.4	$ 21.3

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) $ in Thousands, kr in Millions	Jan. 04, 2018USD ($)	Jan. 04, 2018DKK (kr)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 3,900	kr 24.3
Accretion expense						$ 1,285	$ 1,038	$ 635
Goodwill			$ 122,092			122,092	118,892	151,844	$ 131,122
Goodwill acquired						5,478
Philosophy IB [Member]
Business Acquisition [Line Items]
Goodwill acquired							$ 364	2,357
Acquisition Earnout Adjustment			100	$ 400	$ 700
JCA [Member]
Business Acquisition [Line Items]
Goodwill acquired								15,769
Decision Strategies [Member]
Business Acquisition [Line Items]
Goodwill acquired								$ 5,673
Estimated Fair Value Of Earnout Payment Payable			$ 2,400			2,400
Acquisition Earnout Adjustment						300
Amrop [Member] [Domain]
Business Acquisition [Line Items]
Accrued additional cash consideration	3,100
Identifiable intangible assets	1,700
Goodwill	$ 5,500
Goodwill acquired						$ 5,487

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Beginning Balance	$ 118,892	$ 151,844	$ 131,122
Goodwill acquired	5,478
Goodwill Segment Reallocation			0
Exchange rate fluctuations	(2,278)	2,941	(3,077)
Goodwill, Gross	158,349	155,149
Ending Balance	122,092	118,892	151,844
Goodwill, Impaired, Accumulated Impairment Loss	(36,257)	(36,257)
Goodwill, Impairment Loss		(36,257)
Decision Strategies [Member]
Goodwill [Roll Forward]
Goodwill acquired			5,673
Philosophy IB [Member]
Goodwill [Roll Forward]
Goodwill acquired		364	2,357
JCA [Member]
Goodwill [Roll Forward]
Goodwill acquired			15,769
Amrop [Member] [Domain]
Goodwill [Roll Forward]
Goodwill acquired	5,487
Executive Search [Member]
Goodwill [Roll Forward]
Goodwill, Gross	122,092	118,892
Executive Search [Member] | Americas [Member]
Goodwill [Roll Forward]
Beginning Balance	88,690	88,101	81,626
Goodwill acquired	0		0
Goodwill Segment Reallocation			(1,670)
Exchange rate fluctuations	(280)	232	115
Goodwill, Gross	88,410	88,690
Ending Balance	88,410	88,690	88,101
Goodwill, Impairment Loss		0
Executive Search [Member] | Asia Pacific [Member]
Goodwill [Roll Forward]
Beginning Balance	9,302	8,893	9,211
Goodwill acquired	0	0	0
Goodwill Segment Reallocation			(347)
Exchange rate fluctuations	(544)	409	29
Goodwill, Gross	8,758	9,302
Ending Balance	8,758	9,302	8,893
Goodwill, Impairment Loss		0
Executive Search [Member] | Europe [Member]
Goodwill [Roll Forward]
Beginning Balance	20,900	19,092	10,745
Goodwill acquired		0	0
Goodwill Segment Reallocation			(4,517)
Exchange rate fluctuations	(1,454)	1,808	(2,905)
Goodwill, Gross	24,924	20,900
Ending Balance	24,924	20,900	19,092
Goodwill, Impairment Loss		0
Executive Search [Member] | Decision Strategies [Member] | Americas [Member]
Goodwill [Roll Forward]
Goodwill acquired			5,673
Executive Search [Member] | Philosophy IB [Member] | Americas [Member]
Goodwill [Roll Forward]
Goodwill acquired		357	2,357
Executive Search [Member] | JCA [Member] | Europe [Member]
Goodwill [Roll Forward]
Goodwill acquired			15,769
Executive Search [Member] | Amrop [Member] [Domain] | Europe [Member]
Goodwill [Roll Forward]
Goodwill acquired	5,478
Heidrick Consulting [Domain]
Goodwill [Roll Forward]
Beginning Balance	0	35,758	29,540
Goodwill acquired	0	7	0
Goodwill Segment Reallocation			6,534
Exchange rate fluctuations	0	492	(316)
Goodwill, Gross	36,257	36,257
Ending Balance	$ 0	0	$ 35,758
Goodwill, Impairment Loss		$ (36,257)

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Goodwill - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 04, 2018	Dec. 31, 2015
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Impairment Loss		$ 36,257
Goodwill, Gross	$ 158,349	155,149
Goodwill acquired	5,478
Goodwill, Impaired, Accumulated Impairment Loss	(36,257)	(36,257)
Goodwill	122,092	118,892	$ 151,844		$ 131,122
Amrop [Member] [Domain]
Goodwill And Other Intangible Assets [Line Items]
Goodwill acquired	5,487
Goodwill				$ 5,500
Decision Strategies [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill acquired			5,673
Philosophy IB [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill acquired		364	2,357
JCA [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill acquired			15,769
Culture Shaping [Member]
Goodwill And Other Intangible Assets [Line Items]
Impairment of Intangible Assets, Finite-lived		9,900
Goodwill, Impairment Loss		29,300
Leadership Consulting [Member]
Goodwill And Other Intangible Assets [Line Items]
Impairment of Intangible Assets, Finite-lived		4,600
Goodwill, Impairment Loss		6,900
Executive Search [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Gross	122,092	118,892
Executive Search [Member] | Europe [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Impairment Loss		0
Goodwill, Gross	$ 24,924	20,900
Goodwill acquired		0	0
Percentage of fair value excess by carrying value	19.00%
Goodwill	$ 24,924	20,900	19,092		10,745
Executive Search [Member] | Americas [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Impairment Loss		0
Goodwill, Gross	88,410	88,690
Goodwill acquired	$ 0		0
Percentage of fair value excess by carrying value	335.00%
Goodwill	$ 88,410	88,690	88,101		81,626
Executive Search [Member] | Asia Pacific [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill, Impairment Loss		0
Goodwill, Gross	8,758	9,302
Goodwill acquired	$ 0	0	0
Percentage of fair value excess by carrying value	13.00%
Goodwill	$ 8,758	9,302	8,893		$ 9,211
Executive Search [Member] | Amrop [Member] [Domain] | Europe [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill acquired	$ 5,478
Executive Search [Member] | Decision Strategies [Member] | Americas [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill acquired			5,673
Executive Search [Member] | Philosophy IB [Member] | Americas [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill acquired		$ 357	2,357
Executive Search [Member] | JCA [Member] | Europe [Member]
Goodwill And Other Intangible Assets [Line Items]
Goodwill acquired			$ 15,769

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Summary of Other Intangible Assets Net by Segment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	$ 2,216	$ 2,158
Executive Search [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	2,216	2,158
Executive Search [Member] | Americas [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	52	252
Executive Search [Member] | Europe [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	2,086	1,799
Executive Search [Member] | Asia Pacific [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	78	107
Heidrick Consulting [Domain]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	$ 0	$ 0

Goodwill and Other Intangible_7

Goodwill and Other Intangible Assets - Carrying Amount of Amortizable Intangible Assets and Related Accumulated Amortization (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (in years)	6 years 9 months
Gross Carrying Amount	$ 16,561	$ 14,392
Accumulated Amortization	(14,345)	(12,234)
Net Carrying Amount	$ 2,216	2,158
Client relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (in years)	6 years 9 months
Gross Carrying Amount	$ 15,910	13,703
Accumulated Amortization	(13,694)	(11,612)
Net Carrying Amount	$ 2,216	2,091
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (in years)	0 days
Gross Carrying Amount	$ 434	459
Accumulated Amortization	(434)	(459)
Net Carrying Amount	$ 0	0
Non-compete [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (in years)	0 days
Gross Carrying Amount	$ 217	230
Accumulated Amortization	(217)	(163)
Net Carrying Amount	$ 0	$ 67

Goodwill and Other Intangible_8

Goodwill and Other Intangible Assets - Intangible Assets- Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	$ 2,216	$ 2,158
Intangible asset amortization expense, excluding impairment charge	1,500	$ 4,400	$ 7,100
Estimated Intangible asset amortization expense 2019	846
Estimated Intangible asset amortization expense 2020	529
Estimated Intangible asset amortization expense 2021	356
Estimated Intangible asset amortization expense 2022	241
Estimated Intangible asset amortization expense 2023	147
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	$ 97

Other Non-Current Liabilities -

Other Non-Current Liabilities - Components of Other Non-Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Premise related costs	$ 15,473	$ 18,360
Accrued earnout payments	0	3,076
Restructuring Reserve, Noncurrent	0	10
Other	1,950	2,151
Total other non-current liabilities	$ 17,423	$ 23,597

Other Current Assets and Liab_4

Other Current Assets and Liabilities and Non-Current Liabilities Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Other Current Assets - Components of Other Current Assets [Line Items]
Unbilled Receivables, Current	$ 23,975		$ 3,538
Other Assets, Miscellaneous, Current	5,623		8,082
Other Assets, Current	$ 29,598	$ 26,309	$ 11,620

Other Current Assets and Liab_5

Other Current Assets and Liabilities and Non-Current Liabilities Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Other Current Liabilities [Line Items]
Restructuring Reserve, Current	$ 1,287		$ 13,023
Other Accrued Liabilities, Current	31,932		27,323
Other Liabilities, Current	$ 33,219	$ 44,041	$ 40,346

Line of Credit - Additional Inf

Line of Credit - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2015
Line of Credit Facility [Line Items]
Payments of Debt Issuance Costs					$ 981	$ 0	$ 0
Long-term Line of Credit, Noncurrent					0	0
Proceeds from Lines of Credit					20,000	$ 40,000	$ 0
Senior Unsecured Revolving Line Of Credit Member [Member]
Line of Credit Facility [Line Items]
Borrowing amount under term loan facility								$ 100,000
Sublimit for letters of credit								25,000
Line of credit facility expansion feature								$ 50,000
Proceeds from Lines of Credit		$ 20,000		$ 40,000
Repayments of Long-term Debt	$ 12,000	$ 8,000	$ 25,000	$ 15,000
2018 Credit Agreement [Member]
Line of Credit Facility [Line Items]
Borrowing amount under term loan facility					175,000
Sublimit for letters of credit					25,000
Bridge Loan					10,000
Line of credit facility expansion feature					75,000
Payments of Debt Issuance Costs					$ 1,000

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 1,349,000
Liability, Defined Benefit Plan	20,900,000	$ 23,900,000
Discretionary contribution amount	$ 0	0	$ 0
U.S. Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage to defer up base compensation of employees, effective from January 1, 2006	25.00%
Amount to defer up bonus compensation of employees, effective from January 1, 2006	$ 500,000
Percentage to defer up eligible bonus compensation, effective from January 1, 2006	25.00%
Amount of compensation deferred in plan	$ 18,300,000	19,200,000
Percentage to defer up cash component of director's fees for non-employee [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage to defer up directors' fees	100.00%
Non-Employee Directors Voluntary Deferred Compensation Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Amount of compensation deferred in plan	$ 1,100,000	2,200,000
German Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum amount of employee contributions			$ 6,000
Percentage of eligible compensation			6.00%
Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum amount of employee contributions		$ 6,000
Percentage of eligible compensation		6.00%
Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage for employee pre-tax and/or after-tax contributions, minimum	1.00%
Percentage for employee pre-tax and/or after-tax contributions, maximum	50.00%
Defined Contribution Plan, Cost	$ 5,700,000	$ 5,600,000	$ 4,800,000

Pension Plan and Life Insuran_3

Pension Plan and Life Insurance Contract - Reconcile Benefit Obligation for Pension Plan (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Interest Cost	$ 373	$ 362	$ 453
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	(886)	(371)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	1,450	1,453
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)	$ (1,015)	$ 3,220

Pension Plan and Life Insuran_4

Pension Plan and Life Insurance Contract - Benefit Obligation Amounts Recognized in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Liability, Pension and Other Postretirement and Postemployment Benefits, Current	$ 1,349	$ 1,461
Liability, Pension and Other Postretirement and Postemployment Benefits, Noncurrent	19,559	22,425
Liability, Defined Benefit Plan, Noncurrent	39,865	44,802
Liability, Defined Benefit Plan	$ 20,908	$ 23,886

Pension Plan and Life Insuran_5

Pension Plan and Life Insurance Contract - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Interest Cost	$ 373	$ 362	$ 453
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	1,349
Defined Benefit Plan Amounts in Accumulated Other Comprehensive Income Not Yet Recognized In Net Periodic Benefit Cost	2,600	3,700
Defined Benefit Plan, Amortization of Gain (Loss)	92	111	17
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 465	$ 473	$ 470
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	0.00%	0.00%	0.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	1.60%	1.50%	2.20%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	0.00%	0.00%	0.00%

Pension Plan and Life Insuran_6

Pension Plan and Life Insurance Contract - Assumptions to Determine Company's Benefit Obligation (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	1.70%	1.60%	1.50%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	0.00%	0.00%	0.00%
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Measurement Date	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016

Pension Plan and Life Insuran_7

Pension Plan and Life Insurance Contract - Summary of Benefits Expected to Be Paid in Each of Next Five Years (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Retirement Benefits [Abstract]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 1,349
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	1,339
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	1,326
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	1,309
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	1,289
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	$ 6,001

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Detail) - USD ($) $ in Millions	May 24, 2018	May 22, 2014	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2012
Former Chief Executive Officer [Domain]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation, 2017 Grants Forfeited				100.00%
Share-based Compensation, 2014 Grants to Continue Vesting				100.00%
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance stock units vesting period			3 years
Pre-tax unrecognized compensation expense			$ 5.9
Expected time to be recognized			2 years 7 months
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			297,664	243,306	207,405
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax unrecognized compensation expense			$ 2
Expected time to be recognized			2 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period			102,138	88,415	125,388
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, Expiration 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%
Phantom Share Units (PSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance stock units vesting period			4 years
Pre-tax unrecognized compensation expense			$ 2
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			111,673
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 (in shares)			2,149,864
Shares available for future awards			1,375,105
Number of forfeited awards under 2012 Program (in shares)			674,969
Award expiration date			May 24, 2028

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Information with Respect to Stock-Based Compensation (Detail) - USD ($) $ in Thousands	May 24, 2018	May 22, 2014	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit related to stock-based compensation included in net income			$ 2,674	$ 1,948	$ 2,523
Salaries and Employee Benefits [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Salaries and employee benefits (1)			9,548	4,597	5,830
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
General and administrative expenses			$ 562	$ 338	$ 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 Additional Shares Authorized	850,000	700,000

Stock-based Compensation - Rest

Stock-based Compensation - Restricted Stock Unit Activity (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 5.9
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 (in shares)	491,154	537,273	473,935
Number of Stock Units, Granted (in shares)	297,664	243,306	207,405
Number of Stock Units, Vested and converted to common stock (in shares)	(199,550)	(217,028)	(119,455)
Number of Stock Units, Forfeited (in shares)	(76,822)	(72,397)	(24,612)
Number of Stock Units, Ending balance (in shares)	512,446	491,154	537,273
Weighted- Average Grant-date Fair Value
Weighted-Average Grant-date Fair Value, Beginning balance (in dollars per share)	$ 21.92	$ 20.97	$ 19.98
Weighted-Average Grant-date Fair Value, Granted (in dollars per share)	34.64	24.18	22.92
Weighted-Average Grant-date Fair Value, Vested and converted to common stock (in dollars per share)	21.66	21.39	20.02
Weighted-Average Grant-date Fair Value, Forfeited (in dollars per share)	25.76	24.05	22.81
Weighted-Average Grant-date Fair Value, Ending balance (in dollars per share)	$ 28.83	$ 21.92	$ 20.97
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 7 months
Special Restricted Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years

Stock-based Compensation - Perf

Stock-based Compensation - Performance Stock Unit Activity (Detail) - Performance Stock Units [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 2
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 (in shares)	185,891	236,812	272,024
Number of Stock Units, Granted (in shares)	102,138	88,415	125,388
Number of Stock Units, Vested and converted to common stock (in shares)	(43,361)	(70,652)	(160,600)
Number of Stock Units, Forfeited (in shares)	(47,551)	(68,684)	0
Number of Stock Units, Ending balance (in shares)	197,117	185,891	236,812
Weighted- Average Grant-date Fair Value
Weighted-Average Grant-date Fair Value, Beginning balance (in dollars per share)	$ 23.82	$ 22.64	$ 18.28
Weighted-Average Grant-date Fair Value, Granted (in dollars per share)	25.81	23.83	22.98
Weighted-Average Grant-date Fair Value, Vested and converted to common stock (in dollars per share)	23.64	19.65	15.51
Weighted-Average Grant-date Fair Value, Forfeited (in dollars per share)	23.87	24.07	0
Weighted-Average Grant-date Fair Value, Ending balance (in dollars per share)	$ 24.88	$ 23.82	$ 22.64
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years

Stock-Based Compensation Stock-

Stock-Based Compensation Stock-based Compensation - Phantom Stock Unit Activity (Details) - Performance Shares [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Schedule of Nonvested Performance-based Phantom Units [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost	$ 1.2
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	111,673	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	111,673
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
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
Deferred Compensation Share-based Arrangements, Liability, Current and Noncurrent	$ 1.2

Changes in Accumulated Other _3

Changes in Accumulated Other Comprehensive Income - Changes in Accumulated Other Comprehensive Income ("AOCI") by Component (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 13,315
Amount reclassified from AOCI	0
Net current period other comprehensive income	(3,164)	$ (9,993)	$ 5,937
Ending balance	4,062	13,315
Available-for-Sale Securities Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	6,089
Other comprehensive income before classification, net of tax	0
Amount reclassified from AOCI	0
Net current period other comprehensive income	0
Ending balance	0	6,089
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	9,143
Other comprehensive income before classification, net of tax	(3,885)
Amount reclassified from AOCI	0
Net current period other comprehensive income	(3,885)
Ending balance	5,258	9,143
Pension Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(1,917)
Other comprehensive income before classification, net of tax	721
Amount reclassified from AOCI	0
Net current period other comprehensive income	721
Ending balance	(1,196)	(1,917)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive income before classification, net of tax	(3,164)
Net current period other comprehensive income	(3,164)	$ (9,993)	$ 5,937
Accounting Standards Update 2016-01 [Member] | Available-for-Sale Securities Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Amount reclassified from AOCI	(6,089)
Accounting Standards Update 2016-01 [Member] | Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Amount reclassified from AOCI	0
Accounting Standards Update 2016-01 [Member] | Pension Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Amount reclassified from AOCI	0
Accounting Standards Update 2016-01 [Member] | AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Amount reclassified from AOCI	$ (6,089)

Restructuring (Details)

Restructuring (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 0	$ 15,666	$ 0

Restructuring Restructuring Cha

Restructuring Restructuring Charges Additional Details (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 0	$ 15,666	$ 0
Restructuring and Related Cost, Number of Positions Eliminated		251
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 13,065
Other Professional and Consulting Fees [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		2,293
Real Estate Related Expenses [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		308
Executive Search [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		6,823
Heidrick Consulting [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		3,393
Corporate, Non-Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		5,450
Americas [Member] | Executive Search [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		784
Europe [Member] | Executive Search [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		3,993
Asia Pacific [Member] | Executive Search [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 2,046

Restructuring Restructuring C_2

Restructuring Restructuring Charges and Related Cash Payments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Restructuring Charges and Related Cash Payments [Line Items]
Restructuring Reserve	$ 1,286	$ 13,025	$ 0
Restructuring Charges	0	15,666	0
Payments for Restructuring	(9,930)	(2,486)
Restructuring Charges, Non-cash Write-offs	195	(155)
Other Restructuring Costs	(1,933)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	(71)
Employee Severance [Member]
Schedule of Restructuring Charges and Related Cash Payments [Line Items]
Restructuring Reserve	1,269	11,866	0
Restructuring Charges		13,065
Payments for Restructuring	(8,689)	(1,199)
Restructuring Charges, Non-cash Write-offs	0	0
Other Restructuring Costs	(1,843)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	(65)
Real Estate Related Expenses [Domain]
Schedule of Restructuring Charges and Related Cash Payments [Line Items]
Restructuring Reserve	0	148	0
Restructuring Charges		308
Payments for Restructuring	(248)	(5)
Restructuring Charges, Non-cash Write-offs	195	(155)
Other Restructuring Costs	(95)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	0
Other Professional and Consulting Fees [Domain]
Schedule of Restructuring Charges and Related Cash Payments [Line Items]
Restructuring Reserve	17	1,011	$ 0
Restructuring Charges		2,293
Payments for Restructuring	(993)	(1,282)
Restructuring Charges, Non-cash Write-offs	0	$ 0
Other Restructuring Costs	(5)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	$ (6)

Income Taxes - Sources of Incom

Income Taxes - Sources of Income before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
United States	$ 47,191	$ (28,577)	$ 30,696
Foreign	23,301	(841)	7,070
Income (loss) before income taxes	$ 70,492	$ (29,418)	$ 37,766

Income Taxes - Provision for (B

Income Taxes - Provision for (Benefit from) Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current
Federal		$ 12,311	$ 10,107	$ 12,261
State and local		4,843	2,372	3,219
Foreign		6,907	8,257	5,668
Current provision for income taxes		24,061	20,736	21,148
Deferred
Federal		6,403	5,642	727
State and local		(354)	(2,951)	(370)
Foreign		(8,913)	(4,210)	848
Deferred provision (benefit) for income taxes		(2,864)	(1,519)	1,205
Total provision for income taxes	$ 4,787	$ 21,197	$ 19,217	$ 22,353

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Statutory U.S. federal income tax rate	21.00%
Valuation allowance	$ 26,460	$ 35,624
Foreign tax credit carryforwards	$ 8,163	8,128
Losses carried forward	Indefinitely or for periods ranging from five to twenty years
Unremitted earnings held in foreign subsidiaries	$ 75,500	74,100
Tax provided on earnings	900	1,600
Unremitted earnings intended to be remitted	7,200	15,700
Unrecognized tax benefits	$ 1,128	$ 740	$ 700	$ 1,038	$ 130
Several statutes of limitation expected to close	12 months
Accrued interest and penalties	$ 400
Minimum [Member]
Operating Loss Carryforwards [Line Items]
Foreign tax credit carryforward expiring	5 years	5 years
Operating loss carryforwards ranging period	5 years
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Foreign tax credit carryforward expiring	20 years	20 years
Operating loss carryforwards ranging period	20 years
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	$ 118,000	$ 126,000
Net operating loss carryforward subject to valuation allowance	$ 59,800	95,400
Income tax examination years subject to examination	Years prior to 2014
Deferred Tax Assets, Tax Credit Carryforwards	$ 8,200	8,100
Tax Credit Carryforward, Valuation Allowance	8,200	8,100
Federal Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	$ 100	$ 100
Income tax examination years subject to examination	2015 through 2017
State Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Income tax examination years subject to examination	2015 through 2017

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Provision for (Benefit from) Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%
Income tax provision (benefit) at the statutory U.S. federal rate		$ 14,803	$ (10,296)	$ 13,218
State income tax provision (benefit), net of federal tax benefit		3,242	(593)	1,904
Nondeductible expenses, net		2,587	3,282	1,410
Foreign taxes (includes rate differential and changes in foreign valuation allowance)		(35)	5,465	(2,133)
Establishment (release) of valuation allowance		(43)	(3,200)	340
U.S. tax on foreign dividends		(765)	0	(5,898)
Current/deferred true-up		(1,199)	567	1,226
Effective Income Tax Reconciliation, Tax Reform		0	23,732	0
Other, net		1,077	260	490
Total provision for income taxes	$ 4,787	$ 21,197	$ 19,217	$ 22,353

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Unremitted Earnings Of Foreign Subsidiary Intended To Be Remitted	$ 7,200	$ 15,700
Deferred Tax Liabilities, Undistributed Foreign Earnings	900	1,600
Undistributed Earnings of Foreign Subsidiaries	75,500	74,100
Deferred tax assets attributable to:
Foreign net operating loss carryforwards	18,259	31,960
Accrued compensation and employee benefits	15,442	15,809
Deferred compensation	15,587	13,600
Foreign tax credit carryforwards	8,163	8,128
Accrued rent	3,096	3,607
Other accrued expenses	6,290	2,179
Deferred tax assets, after valuation allowance	66,837	75,283
Valuation allowance	(26,460)	(35,624)
Deferred tax assets, after valuation allowance	40,377	39,659
Deferred tax liabilities attributable to:
Goodwill	2,203	306
Taxes provided on unremitted earnings	765	129
Depreciation on property and equipment	2,040	3,216
Other	686	606
Deferred tax liabilities	5,694	4,257
Net deferred tax assets	34,683	35,402
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	100	100
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	118,000	126,000
Deferred Tax Assets, Tax Credit Carryforwards	8,200	8,100
Tax Credit Carryforward, Valuation Allowance	8,200	8,100
Deferred tax liabilities attributable to:
Operating Loss Carryforwards, Valuation Allowance	$ 59,800	$ 95,400
Minimum [Member]
Deferred tax liabilities attributable to:
Foreign Tax Credit Carryforward Expiring Period	5 years	5 years
Maximum [Member]
Deferred tax liabilities attributable to:
Foreign Tax Credit Carryforward Expiring Period	20 years	20 years

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Amounts of Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Unrecognized Tax Benefits Reconciliation [Roll Forward]
Gross unrecognized tax benefits at January 1,	$ 740	$ 1,038	$ 130
Gross increases for tax positions of prior years	608	167	2,146
Gross decreases for tax positions of prior years	0	0	(4)
Settlements	(220)	(465)	(1,234)
Lapse of statute of limitations	0	0	0
Gross unrecognized tax benefits at December 31,	$ 1,128	$ 740	$ 1,038

Segment Information - Revenue,

Segment Information - Revenue, Operating Income, Depreciation and Amortization, and Capital Expenditures, by Segment (Detail) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Revenue:
Revenue before reimbursements (net revenue)	$ 185,305	$ 716,023	$ 621,400	$ 582,390
Reimbursements	5,662	19,632	18,656	18,516
Total revenue	190,967	735,655	640,056	600,906
Operating Income (Loss)
Operating (loss) income	$ 16,692	68,857	(26,523)	35,233
Depreciation and Amortization
Depreciation and amortization		12,522	14,774	16,433
Capital Expenditures
Capital expenditures		$ 6,185	15,686	8,382
Operating Segments [Member]
Segment Reporting Information [Line Items]
Number of Reportable Segments		4
Operating Income (Loss)
Operating (loss) income		$ 105,109	13,519	76,558
Depreciation and Amortization
Depreciation and amortization		11,563	13,786	14,986
Capital Expenditures
Capital expenditures		5,179	12,388	7,061
Corporate, Non-Segment [Member]
Operating Income (Loss)
Operating (loss) income		(36,252)	(40,042)	(41,325)
Depreciation and Amortization
Depreciation and amortization		959	988	1,447
Capital Expenditures
Capital expenditures		1,006	3,298	1,321
Executive Search [Member] | Operating Segments [Member]
Revenue:
Revenue before reimbursements (net revenue)		652,891	552,044	507,365
Operating Income (Loss)
Operating (loss) income		118,728	75,887	81,880
Depreciation and Amortization
Depreciation and amortization		9,986	9,687	8,144
Capital Expenditures
Capital expenditures		4,598	11,216	6,402
Heidrick Consulting [Domain] | Operating Segments [Member]
Revenue:
Revenue before reimbursements (net revenue)		63,132	69,356	75,025
Operating Income (Loss)
Operating (loss) income		(13,619)	(62,368)	(5,322)
Depreciation and Amortization
Depreciation and amortization		1,577	4,099	6,842
Capital Expenditures
Capital expenditures		581	1,172	659
Americas [Member] | Executive Search [Member] | Operating Segments [Member]
Revenue:
Revenue before reimbursements (net revenue)		405,267	339,793	313,292
Operating Income (Loss)
Operating (loss) income		96,880	75,337	71,993
Depreciation and Amortization
Depreciation and amortization		4,605	4,794	3,892
Capital Expenditures
Capital expenditures		601	7,123	2,221
Europe [Member] | Executive Search [Member] | Operating Segments [Member]
Revenue:
Revenue before reimbursements (net revenue)		145,348	125,346	108,754
Operating Income (Loss)
Operating (loss) income		5,849	13	5,943
Depreciation and Amortization
Depreciation and amortization		3,735	3,328	2,478
Capital Expenditures
Capital expenditures		3,557	1,460	835
Asia Pacific [Member] | Executive Search [Member] | Operating Segments [Member]
Revenue:
Revenue before reimbursements (net revenue)		102,276	86,905	85,319
Operating Income (Loss)
Operating (loss) income		15,999	537	3,944
Depreciation and Amortization
Depreciation and amortization		1,646	1,565	1,774
Capital Expenditures
Capital expenditures		$ 440	$ 2,633	$ 3,346

Segment Information - Identifia

Segment Information - Identifiable Assets, Goodwill and Other Intangible Assets, Net, by Segment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Current assets:
Total allocated current assets	$ 450,867	$ 358,479	$ 343,790
Unallocated non-current assets	125,454		122,364
Intangible Assets, Net (Including Goodwill)	124,308		121,050
Goodwill and other intangible assets, net
Assets	700,629	$ 598,794	587,204
Operating Segments [Member]
Current assets:
Total allocated current assets	449,587		342,702
Corporate, Non-Segment [Member]
Current assets:
Total allocated current assets	1,280		1,088
Executive Search [Member] | Operating Segments [Member]
Current assets:
Total allocated current assets	415,413		311,586
Intangible Assets, Net (Including Goodwill)	124,308		121,050
Heidrick Consulting [Domain] | Operating Segments [Member]
Current assets:
Total allocated current assets	34,174		31,116
Intangible Assets, Net (Including Goodwill)	0		0
Americas [Member] | Executive Search [Member] | Operating Segments [Member]
Current assets:
Total allocated current assets	255,889		171,985
Intangible Assets, Net (Including Goodwill)	88,462		88,942
Europe [Member] | Executive Search [Member] | Operating Segments [Member]
Current assets:
Total allocated current assets	85,355		84,405
Intangible Assets, Net (Including Goodwill)	27,010		22,699
Asia Pacific [Member] | Executive Search [Member] | Operating Segments [Member]
Current assets:
Total allocated current assets	74,169		55,196
Intangible Assets, Net (Including Goodwill)	$ 8,836		$ 9,409

Guarantees - Additional Informa

Guarantees - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Guarantees [Abstract]
Extend termination dates of the leases	extend through 2024
Maximum undiscounted payments under outstanding guarantees	$ 2.6

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Operating Leased Assets [Line Items]
Number of cities in which office spaces leased	49
Lease expiration period description	Through 2,026
Number of countries in which office spaces leased	25
Rent expense, costs of equipment leases and maintenance costs	$ 33,200	$ 32,200	$ 30,800
Aggregate minimum future payments on office leases	$ 151,625
Sublease expiration period	Through 2,019
Asset retirement obligation	$ 2,700	$ 2,900
Office Leases [Member]
Operating Leased Assets [Line Items]
Aggregate minimum future payments on office leases	$ 150,100

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Minimum Future Office Space and Equipment Lease Payments Due (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Operating Leased Assets [Line Items]
2,019	$ 34,456
2,020	31,808
2,021	27,381
2,022	23,445
2,023	20,087
Thereafter	14,448
Total	151,625
Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals	200
Office Leases [Member]
Operating Leased Assets [Line Items]
Total	$ 150,100

Uncategorized Items - hsii-2018

Label	Element	Value
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	$ 198,217,000