Heidrick & Struggles International (HSII) 10-Q 3 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 01, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
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 Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		18,923,363

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 73,358,000		$ 207,534,000	$ 68,329,000	$ 165,011,000
Accounts receivable, net	133,681,000		98,700,000
Prepaid expenses	29,075,000		22,003,000
Other current assets	28,104,000	$ 26,309,000	11,620,000
Income taxes recoverable	4,428,000		3,933,000
Total current assets	268,646,000	358,479,000	343,790,000
Non-current assets:
Property and equipment, net	38,464,000		39,514,000
Assets designated for retirement and pension plans	17,569,000		17,130,000
Investments	22,884,000		21,319,000
Other non-current assets	16,865,000		8,999,000
Goodwill	123,284,000		118,892,000
Other intangible assets, net	(3,943,000)		(2,158,000)
Deferred income taxes	32,691,000	32,303,000	35,402,000
Total non-current assets	255,700,000	240,315,000	243,414,000
Total assets	524,346,000	598,794,000	587,204,000
Current liabilities:
Accounts payable	9,574,000		9,824,000
Accrued salaries and employee benefits	83,414,000		177,426,000
Deferred revenue, net	39,598,000	30,213,000	31,272,000
Other current liabilities	39,499,000	44,041,000	40,346,000
Income taxes payable	8,300,000		6,924,000
Total current liabilities	180,385,000	268,428,000	265,792,000
Long-term Line of Credit	12,000,000		0
Employee-related Liabilities, Non-current	30,951,000		40,308,000
Non-current liabilities:
Retirement and pension plans	46,999,000		44,802,000
Other non-current liabilities	23,522,000		23,597,000
Total non-current liabilities	113,472,000		108,707,000
Total liabilities	293,857,000	377,135,000	374,499,000
Commitments and contingencies (Note 18)
Stockholders’ equity:
Preferred stock, $0.01 par value, 10,000,000 shares authorized, no shares issued at March 31, 2017 and December 31, 2016	0		0
Common stock, $0.01 par value, 100,000,000 shares authorized, 19,585,777 shares issued, 18,731,898 and 18,578,176 shares outstanding at March 31, 2017 and December 31, 2016, respectively	196,000		196,000
Treasury stock at cost, 853,879 and 1,007,601 shares at March 31, 2017 and December 31, 2016, respectively	(21,482,000)		(26,096,000)
Additional paid in capital	220,935,000		226,006,000
Retained earnings	22,024,000	14,327,000	(716,000)
Accumulated other comprehensive income	8,816,000	7,226,000	13,315,000
Total stockholders’ equity	230,489,000	221,659,000	212,705,000
Total liabilities and stockholders’ equity	$ 524,346,000	$ 598,794,000	$ 587,204,000

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value (in USD per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	19,585,777	19,585,777
Common stock, shares outstanding	18,918,965	18,781,433
Treasury stock, shares	666,812	804,344

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue:
Revenue before reimbursements (net revenue)	$ 160,071	$ 140,006
Reimbursements	4,587	4,171
Total revenue	164,658	144,177
Operating expenses:
Salaries and employee benefits	111,409	97,235
General and administrative expenses	35,541	36,133
Reimbursed expenses	4,587	4,171
Total operating expenses	151,537	137,539
Operating income	13,121	6,638
Non-operating income (expense):
Interest, net	239	197
Other, net	(448)	(2,741)
Net non-operating income (expense)	(209)	(2,544)
Income before income taxes	12,912	4,094
Provision for income taxes	(2,744)	(3,444)
Net income	10,168	650
Other comprehensive income, net of tax:
Foreign currency translation adjustment	1,590	1,817
Net unrealized gain on available-for-sale investments	0	808
Other comprehensive income, net of tax	1,590	2,625
Comprehensive income	$ 11,758	$ 3,275
Basic weighted average common shares outstanding (in shares)	18,826	18,628
Diluted weighted average common shares outstanding (in shares)	19,321	19,219
Basic net income per common share (in USD per share)	$ 0.54	$ 0.03
Diluted net income per common share (in USD per share)	0.53	0.03
Cash dividends paid per share (in USD per share)	$ 0.13	$ 0.13

Condensed Consolidated Stateme5

Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Beginning balance at Dec. 31, 2017	$ 212,705	$ 196	$ (26,096)	$ 226,006	$ (716)	$ 13,315
Beginning balance, shares at Dec. 31, 2017	18,781,433	19,586,000	805,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 10,168				10,168
Adoption of New Accounting Pronouncements	8,954				15,043	(6,089)
Other comprehensive income, net of tax	1,590					1,590
Treasury and common stock transactions:
Stock-based compensation	1,776			1,776
Vesting of equity, net of tax withholdings	(2,233)		$ (4,614)	(6,847)
Vesting of equity, net of tax withholdings, shares			138,000
Cash dividends declared ($0.13 per share)	(2,460)				(2,460)
Dividend equivalents on restricted stock units	(11)				(11)
Ending balance at Mar. 31, 2018	$ 230,489	$ 196	$ (21,482)	$ 220,935	$ 22,024	$ 8,816
Ending balance, shares at Mar. 31, 2018	18,918,965	19,586,000	667,000

Condensed Consolidated Stateme6

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

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Total Cash, Cash Equivalents, and Restricted Cash	$ 73,995	$ 68,906
Cash flows—operating activities:
Net income	10,168	650
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	3,184	3,808
Deferred income taxes	(98)	2,381
Stock-based compensation expense	1,776	1,640
Accretion expense related to earnout payments	(364)	(426)
Changes in assets and liabilities, net of effects of acquisitions:
Accounts receivable	32,024	17,179
Accounts payable	(871)	(325)
Accrued expenses	(105,644)	(98,115)
Changes in Restructuring Accrual	(5,642)	0
Deferred revenue	(1,772)	3,871
Income taxes payable, net	503	323
Retirement and pension plan assets and liabilities	1,632	2,393
Prepaid expenses	6,806	2,604
Other assets and liabilities, net	2,276	7,795
Net cash used in operating activities	(137,506)	(110,526)
Cash flows—investing activities:
Payments to Acquire Businesses, Gross	(3,210)	0
Capital expenditures	(1,182)	(4,163)
Purchases of available for sale investments	(1,748)	(1,806)
Proceeds from sales of available for sale investments	145	256
Net cash used in investing activities	(5,995)	(5,713)
Proceeds from Lines of Credit	20,000	40,000
Repayments of Lines of Credit	(8,000)	(15,000)
Cash flows—financing activities:
Cash dividends paid	(2,471)	(2,598)
Payment of employee tax withholdings on equity transactions	(2,233)	(2,392)
Acquisition earnout payments	0	(2,189)
Net cash provided by (used in) financing activities	7,296	17,821
Effect of exchange rates fluctuations on cash and cash equivalents	2,038	1,755
Cash, Cash Equivalents, and Restricted Cash, Period Increase (Decrease)	(134,167)	(96,663)
Cash and cash equivalents at end of period	$ 73,358	$ 68,329

Basis of Presentation of Interi

Basis of Presentation of Interim Financial Information	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation of Interim Financial Information	Basis of Presentation of Interim Financial Information The accompanying unaudited Condensed Consolidated Financial Statements of Heidrick & Struggles International, Inc. and subsidiaries (the “Company”) have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue and expenses. Significant items subject to estimates and assumptions include revenue recognition, income taxes, interim effective tax rate and assessment of goodwill and other intangible assets for impairment. Estimates are subject to a degree of uncertainty and actual results could differ from these estimates. These financial statements and notes are to be read in conjunction with the Company’s Consolidated Financial Statements and Notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 , as filed with the SEC on March 13, 2018 .

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies A complete listing of the Company’s significant accounting policies is discussed in Note 2, Summary of Significant Accounting Policies , in the Notes to Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 . Revenue Recognition As a result of the adoption of ASU 2014-09, Revenue from Contracts with Customers, the Company's accounting policy for revenue recognition has been updated. See Note 3 , Revenue. 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. Current and non-current restricted cash is included in Other current assets and Other non-current assets , respectively, in the Condensed Consolidated Balance Sheets. The following table provides a reconciliation of the cash and cash equivalents between the Condensed Consolidated Balance Sheets and the Condensed Consolidated Statement of Cash Flows as of March 31, 2018 and 2017 , and December 31, 2017 and 2016 : March 31, December 31, 2018 2017 2017 2016 Cash and cash equivalents $ 73,358 $ 68,329 $ 207,534 $ 165,011 Restricted cash included within other current assets 533 147 526 139 Restricted cash included within other non-current assets 104 430 102 419 Total cash, cash equivalents and restricted cash $ 73,995 $ 68,906 $ 208,162 $ 165,569 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 per share: Three Months Ended 2018 2017 Net income $ 10,168 $ 650 Weighted average shares outstanding: Basic 18,826 18,628 Effect of dilutive securities: Restricted stock units 346 431 Performance stock units 149 160 Diluted 19,321 19,219 Basic earnings per share $ 0.54 $ 0.03 Diluted earnings per share $ 0.53 $ 0.03 Recently Issued Financial Accounting Standards In February 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("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 is currently evaluating the impact of this accounting guidance. The effect is not known or reasonably estimable at this time. In February 2016, the FASB issued ASU No. 2016-02, Leases, intended to improve financial reporting about leasing transactions. The new guidance will require 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. ASU 2016-02 is effective for interim and annual periods beginning after December 15, 2018, with early adoption permitted. The guidance requires lessees and lessors to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The Company is currently evaluating the impact of this accounting guidance. The effect is not known or reasonably estimable at this time. Recently Adopted Financial Accounting Standards 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 both diversity in practice, cost and complexity when implementing a change in the terms or conditions of a share-based payment award. ASU 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 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 $0.6 million for each period presented. Changes in the Company's restricted cash balances between periods are immaterial. 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 an impact on the Company's financial statements. On January 1, 2018, the Company adopted ASU 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 three months ended March 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 recognizes 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. 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 2014-09, Revenue from Contracts with Customers, and ASU 2016-01, Financial Instruments: Recognition and Measurement of Financial Assets and Financial Liabilities were 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 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Balance Sheet as of March 31, 2018 was as follows: March 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Current assets Other current assets $ 28,104 $ 12,523 $ 15,581 Total current assets 268,646 253,065 15,581 Non-current assets Deferred income taxes 32,691 35,790 (3,099 ) Total non-current assets 255,700 258,799 (3,099 ) Total assets $ 524,346 $ 511,864 $ 12,482 Current liabilities Accrued salaries and employee benefits $ 83,414 $ 81,690 $ 1,724 Deferred revenue 39,598 42,242 (2,644 ) Other current liabilities 39,499 35,804 3,695 Income taxes payable 8,300 8,072 228 Total current liabilities 180,385 177,382 3,003 Total liabilities 293,857 290,854 3,003 Stockholders' equity Retained earnings (deficit) 22,024 12,545 9,479 Total stockholders’ equity 230,489 221,010 9,479 Total liabilities and stockholders’ equity $ 524,346 $ 511,864 $ 12,482 The impact of ASU 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Comprehensive Income for the three months ended March 31, 2018 was as follows: Three Months Ended March 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Revenue Revenue before reimbursements (net revenue) $ 160,071 $ 157,594 $ 2,477 Reimbursements 4,587 4,587 — Total revenue 164,658 162,181 2,477 Operating expenses Salaries and employee benefits 111,409 109,685 1,724 General and administrative expenses 35,541 35,541 — Reimbursed expenses 4,587 4,587 — Total operating expenses 151,537 149,813 1,724 Operating income 13,121 12,368 753 Non-operating income (expense) Interest, net 239 239 — Other, net (448 ) (448 ) — Net non-operating income (expense) (209 ) (209 ) — Income before income taxes 12,912 12,159 753 Provision for income taxes 2,744 2,516 228 Net income $ 10,168 $ 9,643 $ 525 Basic earnings per share $ 0.54 $ 0.51 $ 0.03 Diluted earnings per share $ 0.53 $ 0.50 $ 0.03 The impact of ASU 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Cash Flows for the three months ended March 31, 2018 was as follows: Three Months Ended March 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Cash flows - operating activities Net income $ 10,168 $ 9,643 $ 525 Changes in assets and liabilities, net of effects of acquisitions: Accrued expenses (105,644 ) (111,063 ) 5,419 Deferred revenue (1,772 ) 2,869 (4,641 ) Income taxes payable, net 503 275 228 Other assets and liabilities, net (2,276 ) (745 ) (1,531 )

Allowance for Doubtful Accounts

Allowance for Doubtful Accounts	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts The activity of the allowance for doubtful accounts is as follows: Balance at December 31, 2017 $ 2,534 Provision charged to income 922 Write-offs (266 ) Foreign currency translation 39 Balance at March 31, 2018 $ 3,229

Property and Equipment, net

Property and Equipment, net	3 Months Ended
	Mar. 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: March 31, December 31, Leasehold improvements $ 47,472 $ 48,216 Office furniture, fixtures and equipment 18,240 17,732 Computer equipment and software 28,978 28,300 Property and equipment, gross 94,690 94,248 Accumulated depreciation (56,226 ) (54,734 ) Property and equipment, net $ 38,464 $ 39,514 Depreciation expense for the three months ended March 31, 2018 and 2017 was $2.8 million and $1.8 million , respectively.

Investments

Investments	3 Months Ended
	Mar. 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 $22.9 million and $21.3 million as of March 31, 2018 and December 31, 2017 , respectively. The aggregate cost basis for these investments was $16.2 million and $14.6 million as of March 31, 2018 and December 31, 2017 , respectively.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 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 March 31, 2018 and December 31, 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 Balance at March 31, 2018 U.S. non-qualified deferred compensation plan $ 22,884 $ — $ — $ 22,884 Assets designated for retirement and pension plans — 19,067 — 19,067 Pension benefit obligation — (24,506 ) — (24,506 ) Acquisition earnout accruals — — (10,669 ) (10,669 ) $ 22,884 $ (5,439 ) $ (10,669 ) $ 6,776 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Balance 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 include accruals for future earnout payments related to prior 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 March 31, 2018 and December 31, 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 assets and liabilities for the three months ended March 31, 2018 : Acquisition Balance at December 31, 2017 $ (7,213 ) Acquisition earnouts (Note 8) (2,880 ) Earnout accretion (364 ) Foreign currency translation (212 ) Balance at March 31, 2018 $ (10,669 )

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Acquisitions	Acquisitions 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 has accrued $3.1 million as of March 31, 2018. The Company recorded $2.1 million of intangible assets related to customer relationships and $3.6 million of goodwill. The goodwill is primarily related to the acquired workforce and strategic fit. The fair value estimate of assets acquired and liabilities assumed, including the earnout liability, customer relationships and goodwill, is pending completion. The Company expects to finalize its estimates of fair value during the three months ended June 30, 2018.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 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: March 31, December 31, 2017 Executive Search Americas $ 88,595 $ 88,690 Europe 48,839 44,407 Asia Pacific 9,357 9,302 Total Executive Search 146,791 142,399 Heidrick Consulting 36,257 36,257 Goodwill, gross 183,048 178,656 Accumulated impairment (59,764 ) (59,764 ) Goodwill, net $ 123,284 $ 118,892 Changes in the carrying amount of goodwill by segment for the three months ended March 31, 2018 , are as follows: Executive Search Heidrick Consulting Americas Europe Asia Pacific Total Gross goodwill at December 31, 2017 $ 88,690 $ 44,407 $ 9,302 $ 36,257 $ 178,656 Accumulated impairment — (23,507 ) — (36,257 ) (59,764 ) Net goodwill at December 31, 2017 88,690 20,900 9,302 — 118,892 Amrop acquisition — 3,632 — — 3,632 Foreign currency translation (95 ) 800 55 — 760 Net goodwill at March 31, 2018 $ 88,595 $ 25,332 $ 9,357 $ — $ 123,284 On January 4, 2018, the Company acquired Amrop and included an estimate of the fair value of the acquired assets and liabilities as of the acquisition date in the Condensed Consolidated Balance Sheets. The Company included an estimated $3.6 million of goodwill related to the acquisition in the Europe segment. The Company's estimate of the fair value of the acquired assets and liabilities is pending completion and is expected to be finalized during the three months ended June 30, 2018. Other Intangible Assets, net The Company’s other intangible assets, net by segment, are as follows: March 31, December 31, 2017 Executive Search Americas $ 193 $ 252 Europe 3,650 1,799 Asia Pacific 100 107 Total Executive Search 3,943 2,158 Heidrick Consulting — — Total other intangible assets, net $ 3,943 $ 2,158 The Company recorded an estimate for customer relationships in the Europe segment of $2.1 million related to the acquisition of Amrop. The Company's estimate of the fair value of the acquired assets and liabilities is pending completion and is expected to be finalized during the three months ended June 30, 2018. The carrying amount of amortizable intangible assets and the related accumulated amortization are as follows: Weighted March 31, 2018 December 31, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Client relationships 6.9 $ 15,921 $ (12,018 ) $ 3,903 $ 13,703 $ (11,612 ) $ 2,091 Trade name 0.0 477 (477 ) — 459 (459 ) — Non-compete 2.0 239 (199 ) 40 230 (163 ) 67 Total intangible assets 6.8 $ 16,637 $ (12,694 ) $ 3,943 $ 14,392 $ (12,234 ) $ 2,158 Intangible asset amortization expense for the three months ended March 31, 2018 and 2017 , was $0.4 million and $1.8 million , respectively. The Company's estimated future amortization expense related to intangible assets as of March 31, 2018 , for the years ended December 31st is as follows: Estimated Future Amortization 2018 $ 958 2019 874 2020 655 2021 552 2022 484 Thereafter 420 Total $ 3,943

Other Non-Current Liabilities

Other Non-Current Liabilities	3 Months Ended
	Mar. 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: March 31, December 31, Contract assets $ 20,052 $ 3,538 Other 8,052 8,082 Total other current assets $ 28,104 $ 11,620 The components of other current liabilities are as follows: March 31, December 31, Restructuring charges $ 7,325 $ 13,023 Other 32,174 27,323 Total other current liabilities $ 39,499 $ 40,346 The components of other non-current liabilities are as follows: March 31, December 31, Premise related costs $ 17,632 $ 18,360 Accrued earnout payments 3,690 3,076 Restructuring charges — 10 Other 2,200 2,151 Total other non-current liabilities $ 23,522 $ 23,597

Line of Credit

Line of Credit	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Line of Credit	Line of Credit On June 30, 2015 , the Company entered into a Second Amended and Restated Credit Agreement (the “Restated Credit Agreement”). The Restated Credit Agreement amended and restated the Credit Agreement executed on June 22, 2011 (the “Credit Agreement”). Pursuant to the Restated Credit Agreement, the Company replaced its Revolving Facility and Term Facility (“Existing Facility”) with 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”). The Replacement Facility will mature on June 30, 2020 . Borrowings under the Restated Credit Agreement bear interest at the Company’s election at the existing Alternate Base Rate (as defined in the Credit Agreement) or Adjusted LIBOR Rate (as defined in the Credit Agreement) plus a spread as determined by the Company’s leverage ratio. Borrowings under the Replacement Facility may be used for working capital, capital expenditures, Permitted Acquisitions (as defined in the Credit Agreement) and for other general corporate purposes of the Company and its subsidiaries. The obligations under the Replacement Facility are guaranteed by certain of the Company’s subsidiaries. During the three months ended March 31, 2018, the Company borrowed $20.0 million under the Restated Credit Agreement and elected the Adjusted LIBOR Rate. The Company subsequently repaid $8.0 million during the three months ended March 31, 2018. As of March 31, 2018 , the Company had $12.0 million of outstanding borrowing under the Restated Credit Agreement. The Company had no outstanding borrowings under the Restated Credit Agreement as of December 31, 2017 . The Company was in compliance with the financial and other covenants under the Restated Credit Agreement and no event of default existed. On April 30, 2018, the Company repaid the $12.0 million of outstanding borrowings under the Restated Credit Agreement.

Stock-based Compensation

Stock-based Compensation	3 Months Ended
	Mar. 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. As of March 31, 2018 , 2,015,470 awards have been issued under the 2012 Program and 620,747 shares remain available for future awards, including 636,217 forfeited awards. The 2012 Program provides that no awards can be granted after May 24, 2022 . The Company measures its stock-based compensation costs based on the grant date fair value of the awards and recognizes these costs in the financial statements over the requisite service period. A summary of information with respect to stock-based compensation is as follows Three Months Ended 2018 2017 Salaries and employee benefits $ 1,776 $ 1,640 Income tax benefit related to stock-based compensation included in net income 470 647 Restricted Stock Units Restricted stock unit activity for the three months ended March 31, 2018 : Number of Weighted- Outstanding on December 31, 2017 491,194 $ 21.92 Granted 169,066 30.45 Vested and converted to common stock (170,036 ) 22.03 Forfeited (42,564 ) 24.01 Outstanding on March 31, 2018 447,660 $ 24.90 As of March 31, 2018 , there was $6.6 million of pre-tax unrecognized compensation expense related to unvested restricted stock units, which is expected to be recognized over a weighted average of 2.5 years . Performance Stock Units The Company grants performance stock units to certain of its senior executives. The performance stock units are generally subject to a cliff vesting at the end of a three -year period. The vesting will vary between 0% and 200% based on the attainment of operating income goals over the three -year vesting period. The performance stock units are expensed on a straight-line basis over the three year vesting period. Performance stock unit activity for the three months ended March 31, 2018 : Number of Stock Units Weighted- 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 (43,057 ) 23.83 Outstanding on March 31, 2018 201,611 $ 24.87 As of March 31, 2018 , there was $3.2 million of pre-tax unrecognized compensation expense related to unvested performance stock units, which is expected to be recognized over a weighted average of 2.5 years .

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company reported income before taxes of $12.9 million and an income tax provision of $2.7 million for the three months ended March 31, 2018 . The Company reported income before taxes of $4.1 million and an income tax provision of $3.4 million for the three months ended March 31, 2017 . The effective tax rates for the three months ended March 31, 2018 and 2017 , were 20.9% and 82.9% , respectively. The effective tax rate for the three months ended March 31, 2018 was impacted by one-time items and the Tax Cuts and Jobs Act enacted on December 22, 2017 in the United States. The effective tax rate for the three months ended March 31, 2017 was impacted by losses that are not benefited for tax purposes and the mix of income. Excluding the impact of one-time items, the Company estimates that its effective tax rate for the year ended December 31, 2018 , will be between 33% and 37% . The full year effective rate for 2018 is primarily the result of one-time items and the Tax Cuts and Jobs Act. On December 22, 2017 , the SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”) to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Tax Reform Act. The Company has recognized the provisional tax impacts related to the revaluation of deferred tax assets and liabilities, foreign earnings intended to be remitted, and the tax on foreign earnings intended to be remitted. The Company has included these amounts in its consolidated financial statements for the quarter ended March 31, 2018 . The ultimate impact may differ from these provisional amounts, possibly materially, due to, among other things, additional analysis, changes in interpretations and assumptions the Company has made, additional regulatory guidance that may be issued, and actions the Company may take as a result of the Tax Reform Act. The accounting is expected to be complete when the 2017 U.S. corporate income tax return is filed in 2018.

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 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 three months ended March 31, 2018 is 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 — 1,590 — 1,590 Amount reclassified from AOCI (1) (6,089 ) — — (6,089 ) Net current period other comprehensive income (6,089 ) 1,590 — (4,499 ) Balance at March 31, 2018 $ — $ 10,733 $ (1,917 ) $ 8,816 (1) Upon adoption of ASC 2016-01, unrealized gains (losses) on available for sale securities was reclassified from AOCI to retained earnings.

Segment Information

Segment Information	3 Months Ended
	Mar. 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 three months ended March 31, 2017, have been recast to conform to the new operating segment structure and corporate cost allocation methodology. The Company currently operates its executive search business in the Americas, Europe (which includes Africa), and Asia Pacific (which includes the Middle East), and operates its Heidrick Consulting business globally. For segment purposes, reimbursements of out-of-pocket expenses classified as revenue and other operating income are reported separately and, therefore, are not included in the results of each segment. The Company believes that analyzing trends in revenue before reimbursements (net revenue), analyzing operating expenses as a percentage of net revenue, and analyzing operating income more appropriately reflects its core operations. The revenue and operating income (loss) by segment are as follows: Three Months Ended 2018 2017 Revenue Executive Search Americas $ 86,303 $ 77,098 Europe 35,681 26,205 Asia Pacific 23,848 21,182 Total Executive Search 145,832 124,485 Heidrick Consulting 14,239 15,521 Revenue before reimbursements (net revenue) 160,071 140,006 Reimbursements 4,587 4,171 Total revenue $ 164,658 $ 144,177 Three Months Ended 2018 2017 Operating income (loss) Executive Search Americas $ 20,635 $ 18,352 Europe 3,254 (296 ) Asia Pacific 4,303 3,010 Total Executive Search 28,192 21,066 Heidrick Consulting (5,230 ) (4,971 ) Total segment operating income 22,962 16,095 Global Operations Support (9,841 ) (9,457 ) Total operating income $ 13,121 $ 6,638

Guarantees

Guarantees	3 Months Ended
	Mar. 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 2019 . 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 guarantees is approximately $2.6 million as of March 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	3 Months Ended
	Mar. 31, 2018
Loss Contingencies [Line Items]
Contingencies Disclosure [Text Block]	18. Commitments and Contingencies 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.

Restructuring (Notes)

Restructuring (Notes)	3 Months Ended
	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Activities Disclosure [Text Block]	13. 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 include: the elimination of two executive officer roles for a flatter leadership structure; a workforce reduction as the firm aligns 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 consist 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. Changes to the accrual for restructuring charges for the three months ended March 31, 2018 , are as follows: Employee Related Office Related Other Total Outstanding on December 31, 2017 $ 11,866 $ 148 $ 1,011 $ 13,025 Cash payments (4,018 ) (248 ) (976 ) (5,242 ) Other (775 ) 205 24 (546 ) Exchange rate fluctuations 89 — (1 ) 88 Outstanding on March 31, 2018 $ 7,162 $ 105 $ 58 $ 7,325

Revenue (Notes)

Revenue (Notes)	3 Months Ended
	Mar. 31, 2018
Unbilled Receivables, Contract Assets and Liabilities [Line Items]
Revenue Recognition, Multiple-deliverable Arrangements, Description [Policy Text Block]	Revenue Recognition As a result of the adoption of ASU 2014-09, Revenue from Contracts with Customers, the Company's accounting policy for revenue recognition has been updated. See Note 3 , Revenue. 3. Revenue Executive Search Revenue is recognized as we satisfy performance obligations by transferring a good or service to a customer. 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 2014-09, and as described in Note 2, Summary of Significant Accounting Policies , 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, which results in an initial recording of a contract’s uptick revenue 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 amount 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 on 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 customer for performance reasons within a specified period of time. The replacement guarantee is an assurance warranty, that 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 customer 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 performance obligations by transferring a good or service to a customer. Heidrick Consulting enters into contracts with customers, 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 generally includes only fixed consideration. Most of our consulting contracts contain one performance obligation which is the overall process of 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 customers 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 options to renew the Enterprise Agreement 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 customer 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 customer 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 customer renewals. Access to SD Connect represents a right to access the Company’s intellectual property that the customer 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 customers will receive and consume the benefits from SD Connect equally throughout the contract period. Revenue related to customer 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 an 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. Unbilled receivables: Unbilled revenue represents contract assets from revenue recognized over time in excess of the amount billed to the customer and the amount billed to the customer 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 customer and the amount billed to the customer is is not just 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 or revenue recognized. The following table outlines the changes in our contract asset and liability balances during the period: January 1, March 31, Variance Contract assets Unbilled receivables $ 5,487 $ 6,493 $ 1,006 Contract assets 12,398 13,559 1,161 Contract liabilities Deferred revenue $ 30,370 $ 39,598 $ 9,228 During the three months ended March 31, 2018 , we recognized revenue of $23.4 million that was included in the contract liabilities balance at the beginning of the period. The amount of revenue recognized during the three months ended March 31, 2018 from performance obligations partially satisfied in previous periods as a result of changes in the estimates of variable consideration was $6.1 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 customers 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.

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Earnings Per Share, Policy [Policy Text Block]	The following table sets forth the computation of basic and diluted earnings per share: Three Months Ended 2018 2017 Net income $ 10,168 $ 650 Weighted average shares outstanding: Basic 18,826 18,628 Effect of dilutive securities: Restricted stock units 346 431 Performance stock units 149 160 Diluted 19,321 19,219 Basic earnings per share $ 0.54 $ 0.03 Diluted earnings per share $ 0.53 $ 0.03
Revenue Recognition, Multiple-deliverable Arrangements, Description [Policy Text Block]	Revenue Recognition As a result of the adoption of ASU 2014-09, Revenue from Contracts with Customers, the Company's accounting policy for revenue recognition has been updated. See Note 3 , Revenue. 3. Revenue Executive Search Revenue is recognized as we satisfy performance obligations by transferring a good or service to a customer. 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 2014-09, and as described in Note 2, Summary of Significant Accounting Policies , 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, which results in an initial recording of a contract’s uptick revenue 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 amount 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 on 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 customer for performance reasons within a specified period of time. The replacement guarantee is an assurance warranty, that 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 customer 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 performance obligations by transferring a good or service to a customer. Heidrick Consulting enters into contracts with customers, 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 generally includes only fixed consideration. Most of our consulting contracts contain one performance obligation which is the overall process of 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 customers 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 options to renew the Enterprise Agreement 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 customer 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 customer 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 customer renewals. Access to SD Connect represents a right to access the Company’s intellectual property that the customer 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 customers will receive and consume the benefits from SD Connect equally throughout the contract period. Revenue related to customer 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 an 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. Unbilled receivables: Unbilled revenue represents contract assets from revenue recognized over time in excess of the amount billed to the customer and the amount billed to the customer 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 customer and the amount billed to the customer is is not just 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 or revenue recognized. The following table outlines the changes in our contract asset and liability balances during the period: January 1, March 31, Variance Contract assets Unbilled receivables $ 5,487 $ 6,493 $ 1,006 Contract assets 12,398 13,559 1,161 Contract liabilities Deferred revenue $ 30,370 $ 39,598 $ 9,228 During the three months ended March 31, 2018 , we recognized revenue of $23.4 million that was included in the contract liabilities balance at the beginning of the period. The amount of revenue recognized during the three months ended March 31, 2018 from performance obligations partially satisfied in previous periods as a result of changes in the estimates of variable consideration was $6.1 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 customers 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.
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. Current and non-current restricted cash is included in Other current assets and Other non-current assets , respectively, in the Condensed Consolidated Balance Sheets. The following table provides a reconciliation of the cash and cash equivalents between the Condensed Consolidated Balance Sheets and the Condensed Consolidated Statement of Cash Flows as of March 31, 2018 and 2017 , and December 31, 2017 and 2016 : March 31, December 31, 2018 2017 2017 2016 Cash and cash equivalents $ 73,358 $ 68,329 $ 207,534 $ 165,011 Restricted cash included within other current assets 533 147 526 139 Restricted cash included within other non-current assets 104 430 102 419 Total cash, cash equivalents and restricted cash $ 73,995 $ 68,906 $ 208,162 $ 165,569
Recent Financial Accounting Standards	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 per share: Three Months Ended 2018 2017 Net income $ 10,168 $ 650 Weighted average shares outstanding: Basic 18,826 18,628 Effect of dilutive securities: Restricted stock units 346 431 Performance stock units 149 160 Diluted 19,321 19,219 Basic earnings per share $ 0.54 $ 0.03 Diluted earnings per share $ 0.53 $ 0.03 Recently Issued Financial Accounting Standards In February 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("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 is currently evaluating the impact of this accounting guidance. The effect is not known or reasonably estimable at this time. In February 2016, the FASB issued ASU No. 2016-02, Leases, intended to improve financial reporting about leasing transactions. The new guidance will require 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. ASU 2016-02 is effective for interim and annual periods beginning after December 15, 2018, with early adoption permitted. The guidance requires lessees and lessors to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The Company is currently evaluating the impact of this accounting guidance. The effect is not known or reasonably estimable at this time. Recently Adopted Financial Accounting Standards 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 both diversity in practice, cost and complexity when implementing a change in the terms or conditions of a share-based payment award. ASU 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 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 $0.6 million for each period presented. Changes in the Company's restricted cash balances between periods are immaterial. 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 an impact on the Company's financial statements. On January 1, 2018, the Company adopted ASU 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 three months ended March 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 recognizes 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. 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 2014-09, Revenue from Contracts with Customers, and ASU 2016-01, Financial Instruments: Recognition and Measurement of Financial Assets and Financial Liabilities were 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 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Balance Sheet as of March 31, 2018 was as follows: March 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Current assets Other current assets $ 28,104 $ 12,523 $ 15,581 Total current assets 268,646 253,065 15,581 Non-current assets Deferred income taxes 32,691 35,790 (3,099 ) Total non-current assets 255,700 258,799 (3,099 ) Total assets $ 524,346 $ 511,864 $ 12,482 Current liabilities Accrued salaries and employee benefits $ 83,414 $ 81,690 $ 1,724 Deferred revenue 39,598 42,242 (2,644 ) Other current liabilities 39,499 35,804 3,695 Income taxes payable 8,300 8,072 228 Total current liabilities 180,385 177,382 3,003 Total liabilities 293,857 290,854 3,003 Stockholders' equity Retained earnings (deficit) 22,024 12,545 9,479 Total stockholders’ equity 230,489 221,010 9,479 Total liabilities and stockholders’ equity $ 524,346 $ 511,864 $ 12,482 The impact of ASU 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Comprehensive Income for the three months ended March 31, 2018 was as follows: Three Months Ended March 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Revenue Revenue before reimbursements (net revenue) $ 160,071 $ 157,594 $ 2,477 Reimbursements 4,587 4,587 — Total revenue 164,658 162,181 2,477 Operating expenses Salaries and employee benefits 111,409 109,685 1,724 General and administrative expenses 35,541 35,541 — Reimbursed expenses 4,587 4,587 — Total operating expenses 151,537 149,813 1,724 Operating income 13,121 12,368 753 Non-operating income (expense) Interest, net 239 239 — Other, net (448 ) (448 ) — Net non-operating income (expense) (209 ) (209 ) — Income before income taxes 12,912 12,159 753 Provision for income taxes 2,744 2,516 228 Net income $ 10,168 $ 9,643 $ 525 Basic earnings per share $ 0.54 $ 0.51 $ 0.03 Diluted earnings per share $ 0.53 $ 0.50 $ 0.03 The impact of ASU 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Cash Flows for the three months ended March 31, 2018 was as follows: Three Months Ended March 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Cash flows - operating activities Net income $ 10,168 $ 9,643 $ 525 Changes in assets and liabilities, net of effects of acquisitions: Accrued expenses (105,644 ) (111,063 ) 5,419 Deferred revenue (1,772 ) 2,869 (4,641 ) Income taxes payable, net 503 275 228 Other assets and liabilities, net (2,276 ) (745 ) (1,531 )

Summary of Significant Accoun27

Summary of Significant Accounting Policies Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table sets forth the computation of basic and diluted earnings per share: Three Months Ended 2018 2017 Net income $ 10,168 $ 650 Weighted average shares outstanding: Basic 18,826 18,628 Effect of dilutive securities: Restricted stock units 346 431 Performance stock units 149 160 Diluted 19,321 19,219 Basic earnings per share $ 0.54 $ 0.03 Diluted earnings per share $ 0.53 $ 0.03

Summary of Significant Accoun28

Summary of Significant Accounting Policies Effects of Accounting Standards Updates - Balance Sheet (Tables)	3 Months Ended
	Mar. 31, 2018
Item Effected [Line Items]
Balance Sheet Effects of Newly Adopted Accounting Pronouncements [Table Text Block]	The impact of ASU 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Balance Sheet as of March 31, 2018 was as follows: March 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Current assets Other current assets $ 28,104 $ 12,523 $ 15,581 Total current assets 268,646 253,065 15,581 Non-current assets Deferred income taxes 32,691 35,790 (3,099 ) Total non-current assets 255,700 258,799 (3,099 ) Total assets $ 524,346 $ 511,864 $ 12,482 Current liabilities Accrued salaries and employee benefits $ 83,414 $ 81,690 $ 1,724 Deferred revenue 39,598 42,242 (2,644 ) Other current liabilities 39,499 35,804 3,695 Income taxes payable 8,300 8,072 228 Total current liabilities 180,385 177,382 3,003 Total liabilities 293,857 290,854 3,003 Stockholders' equity Retained earnings (deficit) 22,024 12,545 9,479 Total stockholders’ equity 230,489 221,010 9,479 Total liabilities and stockholders’ equity $ 524,346 $ 511,864 $ 12,482 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 2014-09, Revenue from Contracts with Customers, and ASU 2016-01, Financial Instruments: Recognition and Measurement of Financial Assets and Financial Liabilities were 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 Accoun29

Summary of Significant Accounting Policies Cash, Cash Equivalents, and Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2018
Cash, cash equivalents, and restricted [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 three months ended March 31, 2018 was as follows: Three Months Ended March 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Cash flows - operating activities Net income $ 10,168 $ 9,643 $ 525 Changes in assets and liabilities, net of effects of acquisitions: Accrued expenses (105,644 ) (111,063 ) 5,419 Deferred revenue (1,772 ) 2,869 (4,641 ) Income taxes payable, net 503 275 228 Other assets and liabilities, net (2,276 ) (745 ) (1,531 )
Cash, cash equivalents, and restricted [Table Text Block]	The following table provides a reconciliation of the cash and cash equivalents between the Condensed Consolidated Balance Sheets and the Condensed Consolidated Statement of Cash Flows as of March 31, 2018 and 2017 , and December 31, 2017 and 2016 : March 31, December 31, 2018 2017 2017 2016 Cash and cash equivalents $ 73,358 $ 68,329 $ 207,534 $ 165,011 Restricted cash included within other current assets 533 147 526 139 Restricted cash included within other non-current assets 104 430 102 419 Total cash, cash equivalents and restricted cash $ 73,995 $ 68,906 $ 208,162 $ 165,569

Summary of Significant Accoun30

Summary of Significant Accounting Policies Effects of Accounting Standards Updates - Income Statement (Tables)	3 Months Ended
	Mar. 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 2014-09, Revenue from Contracts with Customers, on our Condensed Consolidated Statement of Comprehensive Income for the three months ended March 31, 2018 was as follows: Three Months Ended March 31, 2018 As Reported Balances Without Adoption of ASU 2014-09 Effect of Adoption Higher/(Lower) Revenue Revenue before reimbursements (net revenue) $ 160,071 $ 157,594 $ 2,477 Reimbursements 4,587 4,587 — Total revenue 164,658 162,181 2,477 Operating expenses Salaries and employee benefits 111,409 109,685 1,724 General and administrative expenses 35,541 35,541 — Reimbursed expenses 4,587 4,587 — Total operating expenses 151,537 149,813 1,724 Operating income 13,121 12,368 753 Non-operating income (expense) Interest, net 239 239 — Other, net (448 ) (448 ) — Net non-operating income (expense) (209 ) (209 ) — Income before income taxes 12,912 12,159 753 Provision for income taxes 2,744 2,516 228 Net income $ 10,168 $ 9,643 $ 525 Basic earnings per share $ 0.54 $ 0.51 $ 0.03 Diluted earnings per share $ 0.53 $ 0.50 $ 0.03

Allowance for Doubtful Accoun31

Allowance for Doubtful Accounts (Tables)	3 Months Ended
	Mar. 31, 2018
Schedule of Allowance for Doubtful Accounts Receivable [Line Items]
Schedule of Allowance for Doubtful Accounts Receivable [Table Text Block]	The activity of the allowance for doubtful accounts is as follows: Balance at December 31, 2017 $ 2,534 Provision charged to income 922 Write-offs (266 ) Foreign currency translation 39 Balance at March 31, 2018 $ 3,229

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	3 Months Ended
	Mar. 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: March 31, December 31, Leasehold improvements $ 47,472 $ 48,216 Office furniture, fixtures and equipment 18,240 17,732 Computer equipment and software 28,978 28,300 Property and equipment, gross 94,690 94,248 Accumulated depreciation (56,226 ) (54,734 ) Property and equipment, net $ 38,464 $ 39,514

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Levels of Inputs Used to Measure Fair Value of Assets	The following tables provide a summary of the fair value measurements at March 31, 2018 and December 31, 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 Balance at March 31, 2018 U.S. non-qualified deferred compensation plan $ 22,884 $ — $ — $ 22,884 Assets designated for retirement and pension plans — 19,067 — 19,067 Pension benefit obligation — (24,506 ) — (24,506 ) Acquisition earnout accruals — — (10,669 ) (10,669 ) $ 22,884 $ (5,439 ) $ (10,669 ) $ 6,776 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Balance 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 assets and liabilities for the three months ended March 31, 2018 : Acquisition Balance at December 31, 2017 $ (7,213 ) Acquisition earnouts (Note 8) (2,880 ) Earnout accretion (364 ) Foreign currency translation (212 ) Balance at March 31, 2018 $ (10,669 )

Goodwill and Other Intangible34

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 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 March 31, 2018 , for the years ended December 31st is as follows: Estimated Future Amortization 2018 $ 958 2019 874 2020 655 2021 552 2022 484 Thereafter 420 Total $ 3,943
Changes in Carrying Amount of Goodwill by Segment	Changes in the carrying amount of goodwill by segment for the three months ended March 31, 2018 , are as follows: Executive Search Heidrick Consulting Americas Europe Asia Pacific Total Gross goodwill at December 31, 2017 $ 88,690 $ 44,407 $ 9,302 $ 36,257 $ 178,656 Accumulated impairment — (23,507 ) — (36,257 ) (59,764 ) Net goodwill at December 31, 2017 88,690 20,900 9,302 — 118,892 Amrop acquisition — 3,632 — — 3,632 Foreign currency translation (95 ) 800 55 — 760 Net goodwill at March 31, 2018 $ 88,595 $ 25,332 $ 9,357 $ — $ 123,284
Summary of Other Intangible Assets Net by Segment	The Company’s other intangible assets, net by segment, are as follows: March 31, December 31, 2017 Executive Search Americas $ 193 $ 252 Europe 3,650 1,799 Asia Pacific 100 107 Total Executive Search 3,943 2,158 Heidrick Consulting — — Total other intangible assets, net $ 3,943 $ 2,158
Carrying Amount of Amortizable Intangible Assets and Related Accumulated Amortization	The carrying amount of amortizable intangible assets and the related accumulated amortization are as follows: Weighted March 31, 2018 December 31, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Client relationships 6.9 $ 15,921 $ (12,018 ) $ 3,903 $ 13,703 $ (11,612 ) $ 2,091 Trade name 0.0 477 (477 ) — 459 (459 ) — Non-compete 2.0 239 (199 ) 40 230 (163 ) 67 Total intangible assets 6.8 $ 16,637 $ (12,694 ) $ 3,943 $ 14,392 $ (12,234 ) $ 2,158

Goodwill and Other Intangible35

Goodwill and Other Intangible Assets Goodwill by Segment (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill by Segment [Line Items]
Goodwill by Segment [Table Text Block]	The Company's goodwill by segment is as follows: March 31, December 31, 2017 Executive Search Americas $ 88,595 $ 88,690 Europe 48,839 44,407 Asia Pacific 9,357 9,302 Total Executive Search 146,791 142,399 Heidrick Consulting 36,257 36,257 Goodwill, gross 183,048 178,656 Accumulated impairment (59,764 ) (59,764 ) Goodwill, net $ 123,284 $ 118,892

Goodwill and Other Intangible36

Goodwill and Other Intangible Assets Goodwill, Carrying Amount (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill [Line Items]
Goodwill, Impaired, Accumulated Impairment Loss	Changes in the carrying amount of goodwill by segment for the three months ended March 31, 2018 , are as follows: Executive Search Heidrick Consulting Americas Europe Asia Pacific Total Gross goodwill at December 31, 2017 $ 88,690 $ 44,407 $ 9,302 $ 36,257 $ 178,656 Accumulated impairment — (23,507 ) — (36,257 ) (59,764 ) Net goodwill at December 31, 2017 88,690 20,900 9,302 — 118,892 Amrop acquisition — 3,632 — — 3,632 Foreign currency translation (95 ) 800 55 — 760 Net goodwill at March 31, 2018 $ 88,595 $ 25,332 $ 9,357 $ — $ 123,284

Other Non-Current Liabilities (

Other Non-Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Other Liabilities Disclosure [Abstract]
Components of Other Non-Current Liabilities	The components of other non-current liabilities are as follows: March 31, December 31, Premise related costs $ 17,632 $ 18,360 Accrued earnout payments 3,690 3,076 Restructuring charges — 10 Other 2,200 2,151 Total other non-current liabilities $ 23,522 $ 23,597

Other Non-Current Liabilities O

Other Non-Current Liabilities Other Current Assets (Tables) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Other Current Assets - Components of Other Current Assets [Line Items]
Unbilled Receivables, Current	$ 20,052		$ 3,538
Other Assets, Miscellaneous, Current	8,052		8,082
Other Assets, Current	$ 28,104	$ 26,309	$ 11,620
Other Current Assets [Text Block]	The components of other current assets are as follows: March 31, December 31, Contract assets $ 20,052 $ 3,538 Other 8,052 8,082 Total other current assets $ 28,104 $ 11,620

Other Non-Current Liabilities39

Other Non-Current Liabilities Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Other Current Liabilities [Line Items]
Other Current Liabilities [Table Text Block]	The components of other current liabilities are as follows: March 31, December 31, Restructuring charges $ 7,325 $ 13,023 Other 32,174 27,323 Total other current liabilities $ 39,499 $ 40,346

Stock-based Compensation (Table

Stock-based Compensation (Tables)	3 Months Ended
	Mar. 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 Three Months Ended 2018 2017 Salaries and employee benefits $ 1,776 $ 1,640 Income tax benefit related to stock-based compensation included in net income 470 647
Restricted Stock Unit Activity	Restricted stock unit activity for the three months ended March 31, 2018 : Number of Weighted- Outstanding on December 31, 2017 491,194 $ 21.92 Granted 169,066 30.45 Vested and converted to common stock (170,036 ) 22.03 Forfeited (42,564 ) 24.01 Outstanding on March 31, 2018 447,660 $ 24.90
Performance Stock Unit Activity	Performance stock unit activity for the three months ended March 31, 2018 : Number of Stock Units Weighted- 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 (43,057 ) 23.83 Outstanding on March 31, 2018 201,611 $ 24.87

Changes in Accumulated Other 41

Changes in Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 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 three months ended March 31, 2018 is 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 — 1,590 — 1,590 Amount reclassified from AOCI (1) (6,089 ) — — (6,089 ) Net current period other comprehensive income (6,089 ) 1,590 — (4,499 ) Balance at March 31, 2018 $ — $ 10,733 $ (1,917 ) $ 8,816

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting Information [Line Items]
Revenue and Operating Income (Loss), by Segment	The revenue and operating income (loss) by segment are as follows: Three Months Ended 2018 2017 Revenue Executive Search Americas $ 86,303 $ 77,098 Europe 35,681 26,205 Asia Pacific 23,848 21,182 Total Executive Search 145,832 124,485 Heidrick Consulting 14,239 15,521 Revenue before reimbursements (net revenue) 160,071 140,006 Reimbursements 4,587 4,171 Total revenue $ 164,658 $ 144,177 Three Months Ended 2018 2017 Operating income (loss) Executive Search Americas $ 20,635 $ 18,352 Europe 3,254 (296 ) Asia Pacific 4,303 3,010 Total Executive Search 28,192 21,066 Heidrick Consulting (5,230 ) (4,971 ) Total segment operating income 22,962 16,095 Global Operations Support (9,841 ) (9,457 ) Total operating income $ 13,121 $ 6,638

Restructuring (Tables)

Restructuring (Tables)	3 Months Ended
	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Activities Disclosure [Text Block]	Changes to the accrual for restructuring charges for the three months ended March 31, 2018 , are as follows: Employee Related Office Related Other Total Outstanding on December 31, 2017 $ 11,866 $ 148 $ 1,011 $ 13,025 Cash payments (4,018 ) (248 ) (976 ) (5,242 ) Other (775 ) 205 24 (546 ) Exchange rate fluctuations 89 — (1 ) 88 Outstanding on March 31, 2018 $ 7,162 $ 105 $ 58 $ 7,325

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2018
Unbilled Receivables, Contract Assets and Liabilities [Line Items]
Unbilled Receivables, Contract Assets and Liabilities [Table Text Block]	The following table outlines the changes in our contract asset and liability balances during the period: January 1, March 31, Variance Contract assets Unbilled receivables $ 5,487 $ 6,493 $ 1,006 Contract assets 12,398 13,559 1,161 Contract liabilities Deferred revenue $ 30,370 $ 39,598 $ 9,228

Summary of Significant Accoun45

Summary of Significant Accounting Policies Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Attributable to Parent	$ 10,168	$ 650
Weighted Average Number of Shares Outstanding, Basic	18,826	18,628
Weighted Average Number of Shares Outstanding, Diluted	19,321	19,219
Earnings Per Share, Basic	$ 0.54	$ 0.03
Earnings Per Share, Diluted	$ 0.53	$ 0.03
Performance Shares [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	149	160
Restricted Stock Units (RSUs) [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	346	431

Summary of Significant Accoun46

Summary of Significant Accounting Policies Cash, cash equivalents, and restricted cash (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 73,358	$ 207,534	$ 68,329	$ 165,011
Restricted Cash Included with Current Assets	533	526	147	139
Restricted Cash Included with Non-Current Assets	104	102	430	419
Total Cash, Cash Equivalents, and Restricted Cash	$ 73,995	$ 208,162	$ 68,906	$ 165,569

Summary of Significant Accoun47

Summary of Significant Accounting Policies Balance Sheet Effect of Newly Adopted Accounting Pronouncements (Details) - USD ($)	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 73,358,000		$ 207,534,000	$ 68,329,000	$ 165,011,000
Accounts Receivable, Net, Current	133,681,000		98,700,000
Prepaid Expense, Current	29,075,000		22,003,000
Other Assets, Current	28,104,000	$ 26,309,000	11,620,000
Income Taxes Receivable, Current	4,428,000		3,933,000
Assets, Current	268,646,000	358,479,000	343,790,000
Deferred Tax Assets, Net, Noncurrent	32,691,000
Property, Plant and Equipment, Net	38,464,000		39,514,000
Defined Benefit Plan, Assets for Plan Benefits, Retirement and Pension Plans, Noncurrent	17,569,000		17,130,000
Long-term Investments	22,884,000		21,319,000
Other Assets, Noncurrent	16,865,000		8,999,000
Goodwill	123,284,000		118,892,000
Finite-Lived Intangible Assets, Net	3,943,000		2,158,000
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	32,691,000	32,303,000	35,402,000
Assets, Noncurrent	255,700,000	240,315,000	243,414,000
Liabilities, Current	180,385,000	268,428,000	265,792,000
Long-term Line of Credit	12,000,000		0
Employee-related Liabilities, Non-current	30,951,000		40,308,000
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent	46,999,000		44,802,000
Other Liabilities, Noncurrent	23,522,000		23,597,000
Liabilities, Noncurrent	113,472,000		108,707,000
Liabilities	293,857,000	377,135,000	374,499,000
Preferred Stock, Value, Issued	0		0
Common Stock, Value, Issued	196,000		196,000
Treasury Stock, Value	(21,482,000)		(26,096,000)
Additional Paid in Capital, Common Stock	220,935,000		226,006,000
Retained Earnings (Accumulated Deficit)	22,024,000	14,327,000	(716,000)
Accumulated Other Comprehensive Income (Loss), Net of Tax	8,816,000	7,226,000	13,315,000
Stockholders' Equity Attributable to Parent	230,489,000	221,659,000	212,705,000
Liabilities and Equity	524,346,000	598,794,000	587,204,000
Assets	524,346,000	598,794,000	587,204,000
Accounts Payable, Current	9,574,000		9,824,000
Employee-related Liabilities, Current	83,414,000		177,426,000
Deferred Revenue, Current	39,598,000	30,213,000	31,272,000
Other Liabilities, Current	39,499,000	44,041,000	40,346,000
Accrued Income Taxes, Current	8,300,000		6,924,000
Commitments and Contingencies
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other Assets, Current	15,581,000	14,689,000
Assets, Current	15,581,000	14,689,000
Deferred Tax Assets, Net, Noncurrent	(3,099,000)
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent		(3,099,000)
Assets, Noncurrent	(3,099,000)	(3,099,000)
Liabilities, Current	3,003,000	2,636,000
Liabilities	3,003,000	2,636,000
Retained Earnings (Accumulated Deficit)	9,479,000	8,954,000
Accumulated Other Comprehensive Income (Loss), Net of Tax		0
Stockholders' Equity Attributable to Parent	9,479,000	8,954,000
Liabilities and Equity	12,482,000	11,590,000
Assets	12,482,000	11,590,000
Employee-related Liabilities, Current	1,724,000
Deferred Revenue, Current	(2,644,000)	(1,059,000)
Other Liabilities, Current		3,695,000
Accrued Income Taxes, Current	228,000
Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other Assets, Current		0
Assets, Current		0
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent		0
Assets, Noncurrent		0
Liabilities, Current		0
Liabilities		0
Retained Earnings (Accumulated Deficit)		6,089,000
Accumulated Other Comprehensive Income (Loss), Net of Tax		(6,089,000)
Stockholders' Equity Attributable to Parent		0
Liabilities and Equity		0
Assets		0
Deferred Revenue, Current		0
Other Liabilities, Current		$ 0
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other Assets, Current	12,523,000
Assets, Current	253,065,000
Deferred Tax Assets, Net, Noncurrent	35,790,000
Assets, Noncurrent	258,799,000
Liabilities, Current	177,382,000
Liabilities	290,854,000
Retained Earnings (Accumulated Deficit)	12,545,000
Stockholders' Equity Attributable to Parent	221,010,000
Liabilities and Equity	511,864,000
Assets	511,864,000
Employee-related Liabilities, Current	81,690,000
Deferred Revenue, Current	42,242,000
Accrued Income Taxes, Current	$ 8,072,000

Summary of Significant Accoun48

Summary of Significant Accounting Policies Income Statement Effects of Newly Adopted Accounting Pronouncements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Item Effected [Line Items]
Revenue before reimbursements (net revenue)	$ 160,071	$ 140,006
Reimbursement Revenue	4,587	4,171
Revenues	164,658	144,177
Labor and Related Expense	111,409	97,235
General And Administrative Excluding Labor And Related Expense	35,541	36,133
Cost of Reimbursable Expense	4,587	4,171
Operating Expenses	151,537	137,539
Operating Income (Loss)	13,121	6,638
Interest Income (Expense), Net	239	197
Other Nonoperating Income (Expense)	(448)	(2,741)
Nonoperating Income (Expense)	(209)	(2,544)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	12,912	4,094
Income Tax Expense (Benefit)	2,744	3,444
Net Income (Loss) Attributable to Parent	$ 10,168	$ 650
Earnings Per Share, Basic	$ 0.54	$ 0.03
Earnings Per Share, Diluted	$ 0.53	$ 0.03
Accounting Standards Update 2014-09 [Member]
Item Effected [Line Items]
Revenue before reimbursements (net revenue)	$ 2,477
Reimbursement Revenue	0
Revenues	2,477
Labor and Related Expense	1,724
General And Administrative Excluding Labor And Related Expense	0
Cost of Reimbursable Expense	0
Operating Expenses	1,724
Operating Income (Loss)	753
Interest Income (Expense), Net	0
Other Nonoperating Income (Expense)	0
Nonoperating Income (Expense)	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	753
Income Tax Expense (Benefit)	228
Net Income (Loss) Attributable to Parent	$ 525
Earnings Per Share, Basic	$ 0.03
Earnings Per Share, Diluted	$ 0.03
Accounting Standards Update 2014-09 [Member]
Item Effected [Line Items]
Revenue before reimbursements (net revenue)	$ 157,594
Reimbursement Revenue	4,587
Revenues	162,181
Labor and Related Expense	109,685
General And Administrative Excluding Labor And Related Expense	35,541
Cost of Reimbursable Expense	4,587
Operating Expenses	149,813
Operating Income (Loss)	12,368
Interest Income (Expense), Net	239
Other Nonoperating Income (Expense)	(448)
Nonoperating Income (Expense)	(209)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	12,159
Income Tax Expense (Benefit)	2,516
Net Income (Loss) Attributable to Parent	$ 9,643
Earnings Per Share, Basic	$ 0.51
Earnings Per Share, Diluted	$ 0.50

Summary of Significant Accoun49

Summary of Significant Accounting Policies Cash Flow Effect of Newly Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash Flow Effects of ASU 2014-09 [Line Items]
Net Income (Loss) Attributable to Parent	$ 10,168	$ 650
Increase (Decrease) in Accrued Liabilities	(105,644)	(98,115)
Increase (Decrease) in Deferred Revenue	(1,772)	3,871
Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable	503	323
Increase (Decrease) in Other Operating Assets and Liabilities, Net	(2,276)	$ (7,795)
Accounting Standards Update 2014-09 [Member]
Cash Flow Effects of ASU 2014-09 [Line Items]
Net Income (Loss) Attributable to Parent	9,643
Increase (Decrease) in Accrued Liabilities	(111,063)
Increase (Decrease) in Deferred Revenue	2,869
Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable	275
Increase (Decrease) in Other Operating Assets and Liabilities, Net	(745)
Accounting Standards Update 2014-09 [Member]
Cash Flow Effects of ASU 2014-09 [Line Items]
Net Income (Loss) Attributable to Parent	525
Increase (Decrease) in Accrued Liabilities	5,419
Increase (Decrease) in Deferred Revenue	(4,641)
Increase (Decrease) in Income Taxes Payable, Net of Income Taxes Receivable	228
Increase (Decrease) in Other Operating Assets and Liabilities, Net	$ (1,531)

Allowance for Doubtful Accoun50

Allowance for Doubtful Accounts - Summary of Allowance for Doubtful Accounts (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Schedule of Allowance for Doubtful Accounts Receivable [Line Items]
Allowance for Doubtful Accounts Receivable	$ 3,229	$ 2,534
Allowance for Doubtful Accounts Receivable [Roll Forward]
Provision charged to income	922
Write-offs	(266)
Currency	$ 39

Property and Equipment, Net - C

Property and Equipment, Net - Components of Company's Property and Equipment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation	$ 2,800	$ 1,800
Property and equipment, gross	94,690		$ 94,248
Accumulated depreciation	(56,226)		(54,734)
Property and equipment, net	38,464		39,514
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	47,472		48,216
Office Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	18,240		17,732
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 28,978		$ 28,300

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 2.8	$ 1.8

Investments - Components of Com

Investments - Components of Company's Investments (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Long-term investments	$ 22,884	$ 21,319
U.S. Non-Qualified Deferred Compensation Plan [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Available for sale securities	$ 22,884	$ 21,319

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Long-term Investments	$ 22,884	$ 21,319
U.S. Non-Qualified Deferred Compensation Plan [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Aggregate cost basis for investments	16,200	14,600
Fair Value, Inputs, Level 1 [Member] | U.S. Non-Qualified Deferred Compensation Plan [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Long-term Investments	$ 22,900	$ 21,300

Fair Value Measurements - Level

Fair Value Measurements - Levels of Inputs Used to Measure Fair Value of Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of assets	$ 6,776	$ 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	22,884	21,319
Assets Designated for Retirement and Pension Plans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets designated for retirement and pension plans	19,067	18,590
Pension Benefit Obligation [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Defined Benefit Plan, Benefit Obligation	(24,506)	(23,886)
Acquisition Earnout Accruals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition earnout accruals	(10,669)	(7,213)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of assets	22,884	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	22,884	21,319
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of assets	(5,439)	(5,296)
Significant Other Observable Inputs (Level 2) [Member] | Assets Designated for Retirement and Pension Plans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets designated for retirement and pension plans	19,067	18,590
Significant Other Observable Inputs (Level 2) [Member] | Pension Benefit Obligation [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Defined Benefit Plan, Benefit Obligation	(24,506)	(23,886)
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of assets	(10,669)	(7,213)
Significant Unobservable Inputs (Level 3) [Member] | Acquisition Earnout Accruals [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition earnout accruals	$ (10,669)	$ (7,213)

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Beginning and Ending Balance of Level 3 Assets and Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair Value, Asset and Liabilities Measured on Recurring and Nonrecurring Basis, Level 3 [Roll Forward]
Earnout payments	$ 0	$ 2,189
Fair Value, Inputs, Level 3 [Member] | Acquisition Earnout Accruals [Member]
Fair Value, Asset and Liabilities Measured on Recurring and Nonrecurring Basis, Level 3 [Roll Forward]
Beginning balance, acquisition earnout accruals	(7,213)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Business Combination, Acquisition Earnout, Fair Value	(2,880)
Earnout Accretion Fair Value Disclosure	(364)
Foreign currency translation	(212)
Ending balance, acquisition earnout accruals	$ (10,669)

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) $ in Thousands, kr in Millions	Jan. 04, 2018USD ($)	Jan. 04, 2018DKK (kr)	Mar. 31, 2018USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 3,900	kr 24.3
Acquisition earnout payments			$ 0	$ (2,189)
Accretion Expense			364	$ 426
Goodwill			$ 123,284		$ 118,892
Identifiable intangible assets	2,100
Amrop [Member] [Domain]
Business Acquisition [Line Items]
Accrued additional cash consideration	3,100
Goodwill	3,600
Identifiable intangible assets	$ 2,100

Goodwill and Other Intangible58

Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill, Amrop Acquisition	$ 3,632
Goodwill, Gross	183,048	$ 178,656
Goodwill, Impaired, Accumulated Impairment Loss	(59,764)	(59,764)
Goodwill [Roll Forward]
Foreign currency translation	760
Executive Search [Member]
Goodwill [Line Items]
Goodwill, Gross	146,791	142,399
Executive Search [Member] | Americas [Member]
Goodwill [Line Items]
Goodwill, Amrop Acquisition	0
Goodwill, Gross	88,595	88,690
Goodwill, Impaired, Accumulated Impairment Loss	0	0
Goodwill [Roll Forward]
Foreign currency translation	(95)
Executive Search [Member] | Europe [Member]
Goodwill [Line Items]
Goodwill, Amrop Acquisition	3,632
Goodwill, Gross	48,839	44,407
Goodwill, Impaired, Accumulated Impairment Loss	(23,507)	(23,507)
Goodwill [Roll Forward]
Foreign currency translation	800
Executive Search [Member] | Asia Pacific [Member]
Goodwill [Line Items]
Goodwill, Amrop Acquisition	0
Goodwill, Gross	9,357	9,302
Goodwill, Impaired, Accumulated Impairment Loss	0	0
Goodwill [Roll Forward]
Foreign currency translation	55
Heidrick Consulting [Domain]
Goodwill [Line Items]
Goodwill, Amrop Acquisition	0
Goodwill, Gross	36,257	36,257
Goodwill, Impaired, Accumulated Impairment Loss	(36,257)	$ (36,257)
Goodwill [Roll Forward]
Foreign currency translation	$ 0

Goodwill and Other Intangible59

Goodwill and Other Intangible Assets - Summary of Other Intangible Assets Net by Segment (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Jan. 04, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill		$ 2,100
Net Carrying Amount	$ 3,943		$ 2,158
Goodwill	123,284		118,892
Executive Search [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	3,943		2,158
Executive Search [Member] | Americas [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	193		252
Goodwill	88,595		88,690
Executive Search [Member] | Europe [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	3,650		1,799
Goodwill	25,332		20,900
Executive Search [Member] | Asia Pacific [Member]
Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	100		107
Goodwill	9,357		9,302
Heidrick Consulting [Domain]
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 0		$ 0
Amrop [Member] [Domain]
Finite-Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill		2,100
Goodwill		$ 3,600

Goodwill and Other Intangible60

Goodwill and Other Intangible Assets - Carrying Amount of Amortizable Intangible Assets and Related Accumulated Amortization (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 400	$ 1,800
Weighted Average Life (in years)	6 years 9 months 19 days
Gross Carrying Amount	$ 16,637		$ 14,392
Accumulated Amortization	(12,694)		(12,234)
Net Carrying Amount	$ 3,943		2,158
Client Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (in years)	6 years 10 months 25 days
Gross Carrying Amount	$ 15,921		13,703
Accumulated Amortization	(12,018)		(11,612)
Net Carrying Amount	$ 3,903		2,091
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (in years)	0 years
Gross Carrying Amount	$ 477		459
Accumulated Amortization	(477)		(459)
Net Carrying Amount	$ 0		0
Non-compete [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (in years)	2 years
Gross Carrying Amount	$ 239		230
Accumulated Amortization	(199)		(163)
Net Carrying Amount	$ 40		$ 67

Goodwill and Other Intangible61

Goodwill and Other Intangible Assets - Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	$ 958
Finite-Lived Intangible Assets, Amortization Expense, Year Two	874
Finite-Lived Intangible Assets, Amortization Expense, Year Three	655
Finite-Lived Intangible Assets, Amortization Expense, Year Four	552
Finite-Lived Intangible Assets, Amortization Expense, Year Five	484
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	420
Intangible asset amortization expense, excluding impairment charge	400	$ 1,800
Finite-Lived Intangible Assets, Net	$ 3,943		$ 2,158

Goodwill and Other Intangible62

Goodwill and Other Intangible Assets Goodwill by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill, Gross	$ 183,048	$ 178,656
Goodwill, Impaired, Accumulated Impairment Loss	(59,764)	(59,764)
Goodwill	123,284	118,892
Executive Search [Member]
Goodwill [Line Items]
Goodwill, Gross	146,791	142,399
Heidrick Consulting [Domain]
Goodwill [Line Items]
Goodwill, Gross	36,257	36,257
Goodwill, Impaired, Accumulated Impairment Loss	(36,257)	(36,257)
Goodwill	0	0
Americas [Member] | Executive Search [Member]
Goodwill [Line Items]
Goodwill, Gross	88,595	88,690
Goodwill, Impaired, Accumulated Impairment Loss	0	0
Goodwill	88,595	88,690
Europe [Member] | Executive Search [Member]
Goodwill [Line Items]
Goodwill, Gross	48,839	44,407
Goodwill, Impaired, Accumulated Impairment Loss	(23,507)	(23,507)
Goodwill	25,332	20,900
Asia Pacific [Member] | Executive Search [Member]
Goodwill [Line Items]
Goodwill, Gross	9,357	9,302
Goodwill, Impaired, Accumulated Impairment Loss	0	0
Goodwill	$ 9,357	$ 9,302

Other Non-Current Liabilities -

Other Non-Current Liabilities - Components of Other Non-Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Premise related costs	$ 17,632	$ 18,360
Accrued earnout payments	3,690	3,076
Restructuring Reserve, Noncurrent	0	10
Other	2,200	2,151
Total other non-current liabilities	$ 23,522	$ 23,597

Other Non-Current Liabilities64

Other Non-Current Liabilities Other Current Liabilities - Components of Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Other Current Liabilities [Line Items]
Restructuring Reserve, Current	$ 7,325		$ 13,023
Other Accrued Liabilities, Current	32,174		27,323
Other Liabilities, Current	$ 39,499	$ 44,041	$ 40,346

Line of Credit - Additional Inf

Line of Credit - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Jun. 30, 2015
Line of Credit Facility [Line Items]
Proceeds from Lines of Credit		$ 20,000	$ 40,000
Long-term debt, gross		12,000		$ 0
Repayments of Long-term Debt		8,000
Repayments of Lines of Credit		$ 8,000	$ 15,000
Senior Unsecured Revolving Line Of Credit Member [Member]
Line of Credit Facility [Line Items]
Senior unsecured revolving line of credit aggregate commitment					$ 100,000
Sublimit for letters of credit					25,000
Line of credit facility expansion feature					$ 50,000
Subsequent Event [Member]
Line of Credit Facility [Line Items]
Repayments of Long-term Debt	$ 12,000

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	May 22, 2014	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Document Period End Date		Mar. 31, 2018
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense		$ 470	$ 647
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax unrecognized compensation expense		$ 6,600
Expected time to be recognized		2 years 6 months
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax unrecognized compensation expense		$ 3,200
Expected time to be recognized		2 years 6 months
Performance Stock Units [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance stock units vesting period		3 years
Performance Stock Units [Member] | Minimum [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance stock units, variation percentage		0.00%
Performance Stock Units [Member] | Maximum [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance stock units, variation percentage		200.00%
2012 Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized or reserved for issuance with respect to awards granted				1,300,000
Increase in number of shares of common stock reserved for issuance	700,000
Number of stock awards issued under 2012 Program		2,015,470
Shares available for future awards		620,747
Number of forfeited awards under 2012 Program		636,217
Labor and Related Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost		$ 1,776	$ 1,640

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Information with Respect to Stock-Based Compensation (Detail) - USD ($) $ in Thousands	May 22, 2014	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit related to stock-based compensation included in net income		$ 470	$ 647
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	700,000
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period		2,015,470
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		620,747
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested Options Forfeited, Number of Shares		636,217

Stock-based Compensation - Rest

Stock-based Compensation - Restricted Stock Unit Activity (Detail) - Restricted Stock Units [Member] $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $	$ 6.6
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of stock units, beginning balance | shares	491,194
Number of stock units, granted | shares	169,066
Number of stock units, vested and converted to common stock | shares	(170,036)
Number of stock units, forfeited | shares	(42,564)
Number of stock units, ending balance | shares	447,660
Weighted-average grant-date fair value, beginning balance | $ / shares	$ 21.92
Weighted-average grant-date fair value, granted | $ / shares	30.45
Weighted-average grant-date fair value, vested and converted to common stock | $ / shares	22.03
Weighted-average grant-date fair value, forfeited | $ / shares	24.01
Weighted-average grant-date fair value, ending balance | $ / shares	$ 24.90
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 6 months

Stock-based Compensation - Perf

Stock-based Compensation - Performance Stock Unit Activity (Detail) - Performance Stock Units [Member] $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | $	$ 3.2
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 | shares	185,891
Number of stock units, granted | shares	102,138
Number of stock units, vested and converted to common stock | shares	(43,361)
Number of stock units, forfeited | shares	(43,057)
Number of stock units, ending balance | shares	201,611
Weighted-average grant-date fair value, beginning balance | $ / shares	$ 23.82
Weighted-average grant-date fair value, granted | $ / shares	25.81
Weighted-average grant-date fair value, vested and converted to common stock | $ / shares	23.64
Weighted-average grant-date fair value, forfeited | $ / shares	24
Weighted-average grant-date fair value, ending balance | $ / shares	$ 24.87
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 6 months
Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Minimum [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	0.00%
Maximum [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	200.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Results of Operations, Income before Income Taxes [Abstract]
Income before income taxes	$ 12,912	$ 4,094
Provision for income taxes	$ 2,744	$ 3,444
Effective Income Tax Rate Reconciliation, Percent	20.90%	82.90%
Minimum [Member]
Results of Operations, Income before Income Taxes [Abstract]
Forecasted Annual Effective Tax Rate	33.00%
Maximum [Member]
Results of Operations, Income before Income Taxes [Abstract]
Forecasted Annual Effective Tax Rate	37.00%

Changes in Accumulated Other 71

Changes in Accumulated Other Comprehensive Income - Changes in Accumulated Other Comprehensive Income ("AOCI") by Component (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 8,816		$ 7,226	$ 13,315
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net current period other comprehensive income	1,590	$ 2,625
Stockholders' equity attributable to parent	230,489		$ 221,659	212,705
Available-for-Sale Securities Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	0			6,089
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income before classification, net of tax	0
Amount reclassified from AOCI	(6,089)
Net current period other comprehensive income	(6,089)
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	10,733			9,143
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income before classification, net of tax	1,590
Amount reclassified from AOCI	0
Net current period other comprehensive income	1,590
Pension Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(1,917)			(1,917)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income before classification, net of tax	0
Amount reclassified from AOCI	0
Net current period other comprehensive income	0
Accumulated Other Comprehensive Income [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income before classification, net of tax	1,590
Amount reclassified from AOCI	(6,089)
Net current period other comprehensive income	1,590
Stockholders' equity attributable to parent	8,816			$ 13,315
Other Comprehensive Income (Loss), Net of Tax, Net of New Accounting Standards	$ (4,499)

Segment Information - Revenue a

Segment Information - Revenue and Operating Income (Loss), by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue:
Revenue before reimbursements (net revenue)	$ 160,071	$ 140,006
Reimbursements	4,587	4,171
Total revenue	164,658	144,177
Operating income (loss):
Operating (loss) income	13,121	6,638
Operating Segments [Member]
Operating income (loss):
Operating (loss) income	22,962	16,095
Global Operations Support [Member]
Operating income (loss):
Corporate Administrative And Other Expenses	(9,841)	(9,457)
Executive Search [Member] | Operating Segments [Member]
Revenue:
Revenue before reimbursements (net revenue)	145,832	124,485
Operating income (loss):
Operating (loss) income	28,192	21,066
Heidrick Consulting [Domain] | Operating Segments [Member]
Revenue:
Revenue before reimbursements (net revenue)	14,239	15,521
Operating income (loss):
Operating (loss) income	(5,230)	(4,971)
Executive Search and Leadership Consulting Americas Segment [Member] | Executive Search [Member] | Operating Segments [Member]
Revenue:
Revenue before reimbursements (net revenue)	86,303	77,098
Operating income (loss):
Operating (loss) income	20,635	18,352
Executive Search and Leadership Consulting Europe Segment [Member] | Executive Search [Member] | Operating Segments [Member]
Revenue:
Revenue before reimbursements (net revenue)	35,681	26,205
Operating income (loss):
Operating (loss) income	3,254	(296)
Executive Search and Leadership Consulting Asia Pacific Segment [Member] | Executive Search [Member] | Operating Segments [Member]
Revenue:
Revenue before reimbursements (net revenue)	23,848	21,182
Operating income (loss):
Operating (loss) income	$ 4,303	$ 3,010

Guarantees - Additional Informa

Guarantees - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Guarantees [Abstract]
Maximum undiscounted payments under outstanding guarantees	$ 2.6
Extend termination dates of the leases	extend through 2019

Restructuring (Details)

Restructuring (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 7,325	$ 13,025
Restructuring Charges		$ 15,700
Restructuring and Related Cost, Number of Positions Eliminated		251
Payments for Restructuring	(5,242)
Other Restructuring Costs	(546)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	88
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	7,162	$ 11,866
Restructuring Charges		13,100
Payments for Restructuring	(4,018)
Other Restructuring Costs	(775)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	89
Other Professional and Consulting Fees [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	58	1,011
Restructuring Charges		2,300
Payments for Restructuring	(976)
Other Restructuring Costs	(24)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	(1)
Real Estate Related Expenses [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	105	148
Restructuring Charges		$ 300
Payments for Restructuring	(248)
Other Restructuring Costs	(205)
Restructuring Reserve, Foreign Currency Translation Gain (Loss)	$ 0

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Jan. 01, 2018
Contract Assets and Liabilities [Line Items]
Deferred Revenue, Revenue Recognized	$ 23,400
Unbilled Contracts Receivable	6,493	$ 5,487
Increase (Decrease) in Unbilled Contracts Receivable	1,006
Contract Assets	13,559	12,398
Increase (Decrease) in Contract Assets	1,161
Contract Liabilities	39,598	$ 30,370
Increase (Decrease) in Contract Liabilities	9,228
Revenue Recognition, Multiple-deliverable Arrangements, Allocation to Specific Unit of Accounting, Effect of Changes, Selling Price	$ 6,100