Robert Half International (RHI) 10-K 15 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Jan. 31, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	RHI
Entity Registrant Name	HALF ROBERT INTERNATIONAL INC /DE/
Entity Central Index Key	315,213
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		119,078,490
Entity Public Float			$ 7,755,399,413

Consolidated Statements of Fina

Consolidated Statements of Financial Position - USD ($)	Dec. 31, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 276,579,000	$ 294,753,000
Accounts receivable, less allowances of $27,678 and $33,181	794,446,000	732,405,000
Other current assets	402,585,000	404,711,000
Total current assets	1,473,610,000	1,431,869,000
Goodwill	209,958,000	210,885,000
Other intangible assets, net	3,149,000	4,946,000
Property and equipment, net	125,176,000	144,887,000
Noncurrent deferred income taxes	91,204,000	74,867,000
Total assets	1,903,097,000	1,867,454,000
LIABILITIES
Accounts payable and accrued expenses	168,031,000	126,937,000
Accrued payroll and benefit costs	638,769,000	612,899,000
Income taxes payable	12,536,000	7,877,000
Current portion of notes payable and other indebtedness	200,000	183,000
Total current liabilities	819,536,000	747,896,000
Notes payable and other indebtedness, less current portion	457,000	657,000
Other liabilities	19,906,000	13,636,000
Total liabilities	839,899,000	762,189,000
Commitments and Contingencies
STOCKHOLDERS’ EQUITY
Preferred stock, $.001 par value authorized 5,000,000 shares; issued and outstanding zero shares	0	0
Common stock, $.001 par value authorized 260,000,000 shares; issued and outstanding 119,078,491 and 124,261,458 shares	119,000	124,000
Capital surplus	1,079,188,000	1,064,601,000
Accumulated other comprehensive (loss) income	(16,109,000)	3,507,000
Retained earnings	0	37,033,000
Total stockholders’ equity	1,063,198,000	1,105,265,000
Total liabilities and stockholders’ equity	$ 1,903,097,000	$ 1,867,454,000

Consolidated Statements of Fi_2

Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable, allowances	$ 27,678	$ 33,181
Preferred stock, par value (usd per share)	$ 0.001	$ 0.001
Preferred stock, authorized (in shares)	5,000,000	5,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (usd per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	260,000,000	260,000,000
Common stock, issued (in shares)	119,078,491	124,261,458
Common stock, outstanding (in shares)	119,078,491	124,261,458

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Net service revenues	$ 5,800,271	$ 5,266,789	$ 5,250,399
Direct costs of services, consisting of payroll, payroll taxes, benefit costs and reimbursable expenses	3,390,257	3,102,977	3,089,723
Gross margin	2,410,014	2,163,812	2,160,676
Selling, general and administrative expenses	1,821,089	1,646,532	1,606,217
Amortization of intangible assets	1,705	1,563	1,237
Interest income, net	(4,382)	(1,799)	(888)
Income before income taxes	591,602	517,516	554,110
Provision for income taxes	157,314	226,932	210,721
Net income	$ 434,288	$ 290,584	$ 343,389
Net income per share :
Basic (usd per share)	$ 3.60	$ 2.34	$ 2.68
Diluted (usd per share)	$ 3.57	$ 2.33	$ 2.67
Shares:
Basic (in shares)	120,513	124,152	127,991
Diluted (in shares)	121,602	124,892	128,766
Cash dividends declared per share (usd per share)	$ 1.12	$ 0.96	$ 0.88

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
COMPREHENSIVE INCOME:
Net income	$ 434,288	$ 290,584	$ 343,389
Foreign currency translation adjustments, net of tax	(19,616)	24,009	(10,208)
Total comprehensive income	$ 414,672	$ 314,593	$ 333,181

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	COMMON STOCK	CAPITAL SURPLUS	ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME	RETAINED EARNINGS
Balance at beginning of period, (in shares) at Dec. 31, 2015		131,156
Balance at beginning of period at Dec. 31, 2015		$ 131	$ 979,477	$ (10,294)	$ 34,467
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net issuances of restricted stock, (in shares)		1,039
Net issuances of restricted stock		$ 1	(1)
Repurchases of common stock, (in shares)		(4,405)
Repurchases of common stock		$ (4)			(178,780)
Stock-based compensation expense			42,699
Exercises of stock options, (in shares)	7	7
Exercises of stock options			223
Tax impact of equity incentive plans			13
Foreign currency translation adjustments, net of tax	$ (10,208)			(10,208)
Net income	343,389				343,389
Cash dividends ($1.12 per share, $.96 per share and $.88 per share)					(114,514)
Balance at end of period, (in shares) at Dec. 31, 2016		127,797
Balance at end of period at Dec. 31, 2016		$ 128	1,022,411	(20,502)	84,562
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net issuances of restricted stock, (in shares)		918
Net issuances of restricted stock		$ 1	(1)
Repurchases of common stock, (in shares)		(4,454)
Repurchases of common stock		$ (5)			(217,031)
Stock-based compensation expense			42,191
Foreign currency translation adjustments, net of tax	24,009			24,009
Net income	290,584				290,584
Cash dividends ($1.12 per share, $.96 per share and $.88 per share)					(121,082)
Balance at end of period, (in shares) at Dec. 31, 2017		124,261
Balance at end of period at Dec. 31, 2017	1,105,265	$ 124	1,064,601	3,507	37,033
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net issuances of restricted stock, (in shares)		666
Net issuances of restricted stock		$ 1	(1)
Repurchases of common stock, (in shares)		(5,849)
Repurchases of common stock		$ (6)			(364,862)
Stock-based compensation expense			44,953
Foreign currency translation adjustments, net of tax	(19,616)			(19,616)
Net income	434,288				434,288
Cash dividends ($1.12 per share, $.96 per share and $.88 per share)			(30,365)		(106,459)
Balance at end of period, (in shares) at Dec. 31, 2018		119,078
Balance at end of period at Dec. 31, 2018	$ 1,063,198	$ 119	$ 1,079,188	$ (16,109)	$ 0

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
RETAINED EARNINGS
Cash dividends, per share (usd per share)	$ 1.12	$ 0.96	$ 0.88

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 434,288	$ 290,584	$ 343,389
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of intangible assets	1,705	1,563	1,237
Depreciation expense	64,244	63,930	63,078
Stock-based compensation expense—restricted stock and stock units	44,953	42,191	42,699
Excess tax benefits from stock-based compensation	0	0	(1,822)
Deferred income taxes	(15,885)	44,091	(1,868)
Provision for doubtful accounts	11,914	8,022	9,192
Changes in assets and liabilities, net of effects of acquisitions:
Increase in accounts receivable	(86,217)	(17,039)	(15,888)
Increase in accounts payable, accrued expenses, accrued payroll and benefit costs	89,715	47,832	19,726
Increase (decrease) in income taxes payable, net	28,900	(9,655)	(8,246)
Change in other assets, net of change in other liabilities	(1,295)	(18,528)	(9,416)
Net cash flows provided by operating activities	572,322	452,991	442,081
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments for acquisitions, net of cash acquired	0	(1,160)	(2,200)
Capital expenditures	(42,484)	(40,753)	(82,956)
Payments to trusts for employee deferred compensation plans	(46,025)	(36,584)	(27,079)
Net cash flows used in investing activities	(88,509)	(78,497)	(112,235)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repurchases of common stock	(353,509)	(231,724)	(176,031)
Cash dividends paid	(136,423)	(121,000)	(114,164)
Decrease in notes payable and other indebtedness	(183)	(167)	(154)
Excess tax benefits from stock-based compensation	0	0	1,822
Proceeds from exercises of stock options	0	0	223
Net cash flows used in financing activities	(490,115)	(352,891)	(288,304)
Effect of exchange rate changes on cash and cash equivalents	(11,872)	12,949	(5,918)
Net (decrease) increase in cash and cash equivalents	(18,174)	34,552	35,624
Cash and cash equivalents at beginning of period	294,753	260,201	224,577
Cash and cash equivalents at end of period	276,579	294,753	260,201
Cash paid during the year for:
Interest	233	278	266
Income taxes, net of refunds	137,147	190,954	219,415
Non-cash items:
Stock repurchases awaiting settlement	$ 11,359	$ 0	$ 14,688

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations. Robert Half International Inc. (the “Company”) provides specialized staffing and risk consulting services through such divisions as Accountemps ® , Robert Half ® Finance & Accounting , OfficeTeam ® , Robert Half ® Technology , Robert Half ® Management Resources , Robert Half ® Legal , The Creative Group ® , and Protiviti ® . The Company, through its Accountemps , Robert Half Finance & Accounting , and Robert Half Management Resources divisions, is a specialized provider of temporary, full-time, and senior-level project professionals in the fields of accounting and finance. OfficeTeam specializes in highly skilled temporary administrative support professionals. Robert Half Technology provides project and full-time technology professionals. Robert Half Legal provides temporary, project, and full-time staffing of lawyers, paralegals and legal support personnel. The Creative Group provides interactive, design, marketing, advertising and public relations professionals. Protiviti is a global consulting firm that helps companies solve problems in finance, technology, operations, data, analytics, governance, risk and internal audit, and is a wholly owned subsidiary of the Company. Revenues are predominantly derived from specialized staffing services. The Company operates in North America, South America, Europe, Asia and Australia. The Company is a Delaware corporation. Basis of Presentation. The Consolidated Financial Statements (“Financial Statements”) of the Company are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and the rules of the Securities and Exchange Commission (“SEC”). Principles of Consolidation. The Financial Statements include the accounts of the Company and its subsidiaries, all of which are wholly owned. All intercompany balances have been eliminated. Use of Estimates. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Such estimates also include allowances for uncollectible accounts receivable, sales adjustments and allowances, workers’ compensation losses, income and other taxes, and assumptions used in the Company's goodwill impairment assessment and in the valuation of stock grants subject to market conditions. Actual results and outcomes may differ from management's estimates and assumptions. Revenue Recognition. The Company derives its revenues from three segments: temporary and consultant staffing, permanent placement staffing, and risk consulting and internal audit services. Net service revenues as presented on the Consolidated Statements of Operations represent services rendered to customers less sales adjustments and allowances. Reimbursements, including those related to travel and out-of-pocket expenses, are also included in net service revenues, and equivalent amounts of reimbursable expenses are included in direct costs of services. The Company records temporary and consultant staffing revenue on a gross basis as a principal versus on a net basis as an agent in the presentation of revenues and expenses. The Company has concluded that gross reporting is appropriate because the Company (i) has the risk of identifying and hiring qualified employees, (ii) has the discretion to select the employees and establish their price and duties and (iii) bears the risk for services that are not fully paid for by customers. Temporary and consultant staffing revenues—Temporary and consultant staffing revenues are recognized when the services are rendered by the Company’s temporary employees. Employees placed on temporary assignment by the Company are the Company’s legal employees while they are working on assignments. The Company pays all related costs of employment, including workers’ compensation insurance, state and federal unemployment taxes, social security and certain fringe benefits. The Company assumes the risk of acceptability of its employees to its customers. Permanent placement staffing revenues—Permanent placement staffing revenues are recognized when employment candidates accept offers of permanent employment. The Company has a substantial history of estimating the effect of permanent placement candidates who do not remain with its clients through the 90-day guarantee period. Allowances are established to estimate these losses. Fees to clients are generally calculated as a percentage of the new employee’s annual compensation. No fees for permanent placement services are charged to employment candidates. Risk consulting and internal audit revenues—Risk consulting and internal audit services are generally provided on a time-and-material basis or fixed-fee basis. Revenues earned under time-and-material arrangements and fixed-fee arrangements are recognized using a proportional performance method as hours are incurred relative to total estimated hours for the engagement. The Company periodically evaluates the need to provide for any losses on these projects, and losses are recognized when it is probable that a loss will be incurred. Costs of Services. Direct costs of temporary and consultant staffing consist of payroll, payroll taxes and benefit costs for the Company’s temporary employees, as well as reimbursable expenses. Direct costs of permanent placement staffing services consist of reimbursable expenses. Risk consulting and internal audit costs of services include professional staff payroll, payroll taxes and benefit costs, as well as reimbursable expenses. Advertising Costs. The Company expenses all advertising costs as incurred. Advertising costs for the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table (in thousands): Years Ended December 31, 2018 2017 2016 Advertising Costs $ 52,499 $ 49,433 $ 47,312 Comprehensive Income. Comprehensive income includes net income and certain other items that are recorded directly to Stockholders’ Equity. The Company’s only source of other comprehensive income is foreign currency translation adjustments. Fair Value of Financial Instruments. The Company does not have any financial instruments which require re-measurement to fair value. The carrying values of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses represent fair value based upon their short-term nature. Cash and Cash Equivalents. The Company considers all highly liquid investments with a maturity at the date of purchase of three months or less as cash equivalents. Accounts Receivable Allowances. The Company maintains allowances for estimated losses resulting from (i) the inability of its customers to make required payments and (ii) sales adjustments. The Company establishes these allowances based on its review of customers’ credit profiles, historical loss statistics and current trends. The adequacy of these allowances is reviewed each reporting period. Historically, the Company’s actual losses have been consistent with these allowances. Goodwill and Intangible Assets . Goodwill and intangible assets primarily consist of the cost of acquired companies in excess of the fair market value of their net tangible assets at the date of acquisition. Identifiable intangible assets are amortized over their lives, typically ranging from two to five years . Goodwill is not amortized, but is tested at least annually for impairment. The Company completed its annual goodwill impairment assessment as of June 30 in each of the three years ended December 31, 2018 , and determined that no adjustment to the carrying value of goodwill was required. There were no events or changes in circumstances during the six months ended December 31, 2018 that caused the Company to perform an interim impairment assessment. Income Taxes . The Company’s operations are subject to U.S. federal, state and local, and foreign income taxes. In establishing its deferred income tax assets and liabilities and its provision for income taxes, the Company makes judgments and interpretations based on the enacted tax laws that are applicable to its operations in various jurisdictions. Deferred tax assets and liabilities are measured and recorded using current enacted tax rates, which the Company expects will apply to taxable income in the years in which those temporary differences are recovered or settled. The likelihood of a material change in the Company’s expected realization of its deferred tax assets is dependent on future taxable income and the effectiveness of its tax planning strategies in the various relevant jurisdictions. On December 22, 2017, the President signed the Tax Cuts and Jobs Act (“TCJA”) into law. Effective January 1, 2018, among other changes, TCJA reduced the federal corporate tax rate to 21 percent, provided for a deemed repatriation and taxation at reduced rates of certain foreign earnings, and established new mechanisms to tax certain foreign earnings going forward. Similar to other large multinational companies, TCJA has wide ranging implications for the Company. In December 2017, the SEC issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act, which allowed the Company to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. The Company completed its TCJA analysis and recorded its final adjustments, which were not material, in the fourth quarter of 2018. The Company also evaluates the need for valuation allowances to reduce the deferred tax assets to realizable amounts. Management evaluates all positive and negative evidence and uses judgment regarding past and future events, including operating results, to help determine when it is more likely than not that all or some portion of the deferred tax assets may not be realized. When appropriate, a valuation allowance is recorded against deferred tax assets to offset future tax benefits that may not be realized. Valuation allowances of $23.1 million and $20.2 million were recorded as of December 31, 2018 and 2017 , respectively. The valuation allowances recorded related primarily to net operating losses in certain foreign operations. If such losses are ultimately utilized to offset future operating income, the Company will recognize a tax benefit up to the full amount of the valuation reserve. Workers’ Compensation . Except for states which require participation in state-operated insurance funds, the Company retains the economic burden for the first $0.5 million per occurrence in workers’ compensation claims. Workers’ compensation includes ongoing healthcare and indemnity coverage for claims and may be paid over numerous years following the date of injury. Claims in excess of $0.5 million are insured. Workers’ compensation expense includes the insurance premiums for claims in excess of $0.5 million , claims administration fees charged by the Company’s workers’ compensation administrator, premiums paid to state-operated insurance funds, and an estimate for the Company’s liability for Incurred But Not Reported (“IBNR”) claims and for the ongoing development of existing claims. The reserves for IBNR claims and for the ongoing development of existing claims in each reporting period includes estimates. The Company has established reserves for workers’ compensation claims using loss development rates which are estimated using periodic third party actuarial valuations based upon historical loss statistics which include the Company’s historical frequency and severity of workers’ compensation claims, and an estimate of future cost trends. While management believes that its assumptions and estimates are appropriate, significant differences in actual experience or significant changes in assumptions may materially affect the Company’s future results. Foreign Currency Translation. The reporting currency of the Company and its subsidiaries is the U.S. dollar. The functional currency of the Company's foreign subsidiaries is their local currency. The results of operations of the Company’s foreign subsidiaries are translated at the monthly average exchange rates prevailing during the period. The financial position of the Company’s foreign subsidiaries is translated at the current exchange rates at the end of the period, and the related translation adjustments are recorded as a component of accumulated other comprehensive income within Stockholders’ Equity. Gains and losses resulting from foreign currency transactions are included as a component of selling, general and administrative expenses in the Consolidated Statements of Operations, and have not been material for all periods presented. Stock-based Compensation . Under various stock plans, officers, employees and outside directors have received or may receive grants of restricted stock, stock units, stock appreciation rights or options to purchase common stock. The Company recognizes compensation expense equal to the grant-date fair value for all stock-based payment awards that are expected to vest. This expense is recorded on a straight-line basis over the requisite service period of the entire award, unless the awards are subject to performance conditions, in which case the Company recognizes compensation expense over the requisite service period of each separate vesting tranche. The Company determines the grant-date fair value of its restricted stock and stock unit awards using the fair market value of its stock on the grant date, unless the awards are subject to market conditions, in which case the Company utilizes a binomial-lattice model (i.e., Monte Carlo simulation model). The Monte Carlo simulation model utilizes multiple input variables to determine the stock-based compensation expense. No stock appreciation rights have been granted under the Company’s existing stock plans. The Company has not granted any options to purchase common stock since 2006. Property and Equipment . Property and equipment are recorded at cost. Depreciation expense is computed using the straight-line method over the following useful lives: Computer hardware 2 to 3 years Computer software 2 to 5 years Furniture and equipment 5 years Leasehold improvements Term of lease, 5 years maximum Internal-use Software. The Company capitalizes direct costs incurred in the development of internal-use software. Amounts capitalized are reported as a component of computer software within property and equipment. Internal-use software development costs capitalized for the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table (in thousands): Years Ended December 31, 2018 2017 2016 Internal-use software development costs $ 3,287 $ 9,030 $ 33,753

New Accounting Pronouncements

New Accounting Pronouncements	12 Months Ended
	Dec. 31, 2018
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements Recently Adopted Accounting Pronouncements Revenue from Contracts with Customers. In May 2014, the Financial Accounting Standards Board (“FASB”) issued authoritative guidance that provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The new guidance requires a company to recognize revenue to depict the transfer of goods or services to a customer at an amount that reflects the consideration it expects to receive in exchange for those goods or services. The Company adopted the new guidance, using the modified retrospective method applied to all contracts not completed as of January 1, 2018, and since the adoption of the new guidance was not material, no adjustment was made to opening retained earnings. The Company also had no significant changes to systems, processes, or controls. The adoption of the guidance did not have a material impact on the Company’s income statement. In accordance with the new guidance, the Company reclassified certain allowances that are now reflected as liabilities. The impact to the Company’s balance sheet is as follows (in thousands): December 31, 2018 As Reported Balances Without Adoption of Revenue Guidance Effect of Change Higher (Lower) Assets Accounts receivable, net $ 794,446 $ 783,776 $ 10,670 Liabilities Accounts payable and accrued expenses $ 168,031 $ 157,361 $ 10,670 Stock Compensation. In May 2017, the FASB issued authoritative guidance updating which changes in the terms or conditions of a share-based payment award require an entity to apply modification accounting. Under the amended guidance, entities are required to account for the effects of a modification if the fair value, vesting conditions or classification (as an equity instrument or a liability instrument) of the modified award change from that of the original award immediately before the modification. The Company adopted the new guidance as of January 1, 2018. The adoption of this guidance did not have a material impact on the Company’s financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted Lease Accounting . In February 2016, the FASB issued authoritative guidance which changes financial reporting as it relates to leasing transactions. Under the new guidance, lessees will be required to recognize a lease liability, measured on a discounted basis; and a right-of-use asset, for the lease term. Lessees and lessors may elect to apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements; or they may elect to apply the provisions of the guidance, using a prospective approach, beginning at the adoption date and recognize a cumulative effect adjustment to opening retained earnings in the period of adoption. The new standard was effective for the Company beginning January 1, 2019, and the Company implemented the new standard using a prospective approach. Upon adoption, the Company elected the package of practical expedients available under the new standard, which allowed the Company to forgo a reassessment of (1) whether any expired or existing contracts are or contain leases, (2) the lease classification for any expired or existing leases, and (3) the initial direct costs for any existing leases. The Company adopted this guidance as of January 1, 2019, using the transition method that allowed it to initially apply the guidance as of January 1, 2019, and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. This adjustment to the opening balance of retained earnings was not material. In addition to certain changes to its systems and processes, the estimated impact of the adoption of this guidance included the recognition of $270 million to $290 million of lease liabilities and right of use assets on the Company’s Consolidated Statement of Financial Position, offset by approximately $30 million of accrued rent, which reduced the right-of-use assets. Current Expected Credit Losses Model. In June 2016, the FASB issued authoritative guidance amending how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. The guidance requires the application of a current expected credit loss model, which is a new impairment model based on expected losses. The new guidance is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted for annual reporting periods beginning after December 15, 2018. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements and related disclosures. Simplifying the Test for Goodwill Impairment. In January 2017, the FASB issued authoritative guidance to simplify the goodwill impairment testing process. The new standard eliminates Step 2 of the goodwill impairment test. If a company determines in Step 1 of the goodwill impairment test that the carrying value of goodwill is greater than the fair value, an impairment in that amount should be recorded to the income statement, rather than proceeding to Step 2. The new guidance is effective for the Company for fiscal years beginning after December 15, 2019, although early adoption is permitted. The Company believes the adoption of this guidance will not have a material impact on its financial statements. Cloud Computing. In August 2018, the FASB issued authoritative guidance which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. Entities are required to present the expense related to capitalized implementation costs in the same line item in the statement of operations as the fees associated with the hosting elements of the arrangement and classify the payments for the capitalized implementation costs in the statement of cash flows in the same manner as payments made for fees associated with the hosting element. Entities are also required to present the capitalized implementation costs in the statement of financial position in the same line item that a prepayment of the fees of the associated hosting arrangement would be presented. The new guidance is effective for the Company for annual and interim periods beginning after December 15, 2019, although early adoption is permitted. The Company has adopted the new guidance as of January 1, 2019, and the impact of adoption was not material to its financial statements.

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition Revenues from contracts with customers are generated in three segments: temporary and consultant staffing, permanent placement staffing, and risk consulting and internal audit services. Revenues are recognized when promised goods or services are delivered to customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those goods or services. Net service revenues, as presented on the Consolidated Statements of Operations, represent services rendered to customers less variable consideration, such as sales adjustments and allowances. Reimbursements, including those related to travel and out-of-pocket expenses, are recorded on a gross basis and included in net service revenues, with equivalent amounts of reimbursable expenses included in direct costs of services. Temporary and consultant staffing revenues. Temporary and consultant staffing revenues from contracts with customers are recognized in the amount to which the Company has a right to invoice, when the services are rendered by the Company’s temporary employees. The Company records temporary and consultant staffing revenue on a gross basis as a principal versus on a net basis as an agent in the presentation of revenues and expenses. The Company has concluded that gross reporting is appropriate because the Company (i) has the risk of identifying and hiring qualified employees, (ii) has the discretion to select the employees and establish their price and duties and (iii) bears the risk for services that are not fully paid for by customers. Fees paid to Time Management or Vendor Management service providers selected by clients are recorded as a reduction of revenues, as the Company is not the primary obligor with respect to those services. The substantial majority of employees placed on temporary assignment by the Company are the Company’s legal employees while they are working on assignments. The Company pays all related costs of employment, including workers’ compensation insurance, state and federal unemployment taxes, social security and certain fringe benefits. The Company assumes the risk of acceptability of its employees to its customers. Permanent placement staffing revenues. Permanent placement staffing revenues from contracts with customers are primarily recognized when employment candidates accept offers of permanent employment. The Company has a substantial history of estimating the financial impact of permanent placement candidates who do not remain with its clients through the 90 -day guarantee period. These amounts are established based primarily on historical data and are recorded as liabilities. Fees to clients are generally calculated as a percentage of the new employee’s annual compensation. No fees for permanent placement services are charged to employment candidates. Risk consulting and internal audit services revenues. Risk consulting and internal audit services generally contain one or more performance obligation(s) which are satisfied over a period of time. Revenues are recognized over time as the performance obligations are satisfied, because the services provided do not have any alternative use to the Company, and contracts generally include language giving the Company an enforceable right to payment for services provided to date. Revenue is measured using cost incurred relative to total estimated cost for the engagement to measure progress towards satisfying the Company’s performance obligations. Cost incurred represents work performed and thereby best depicts the transfer of control to the customer. The following table presents the Company’s revenues disaggregated by line of business (in thousands): Years Ended December 31, 2018 2017 2016 Accountemps $ 1,915,054 $ 1,765,666 $ 1,786,276 OfficeTeam 1,063,238 984,873 972,414 Robert Half Technology 682,889 629,278 659,844 Robert Half Management Resources 669,385 631,225 608,243 Temporary and consulting staffing 4,330,566 4,011,042 4,026,777 Permanent placement staffing 511,989 439,214 419,314 Risk consulting and internal audit services 957,716 816,533 804,308 Net service revenues $ 5,800,271 $ 5,266,789 $ 5,250,399 Payment terms in our contracts vary by the type and location of our customer and the services offered. The term between invoicing and when payment is due is not significant. Contracts with multiple performance obligations are recognized as performance obligations are delivered, and contract value is allocated based on relative stand-alone selling values of the services and products in the arrangement. As of December 31, 2018 , aggregate transaction price allocated to the performance obligations that are unsatisfied for contracts with an expected duration of greater than one year was $58.8 million . Of this amount, $54.9 million is expected to be recognized within the next twelve months . There were no revenues recognized in the twelve months ended December 31, 2018 , related to performance obligations satisfied or partially satisfied in previous periods. Contract assets are recorded when services are performed in advance of the Company’s unconditional right to payment. Contract assets as of January 1, 2018 and December 31, 2018 , were not material. Contract liabilities are recorded when cash payments are received or due in advance of performance and are reflected in Accounts payable and accrued expenses on the Consolidated Statements of Financial Position. The following table sets forth the activity in contract liabilities from January 1, 2018 through December 31, 2018 (in thousands): December 31, 2018 Balance at beginning of period $ 9,003 Payments in advance of satisfaction of performance obligations 12,170 Revenue recognized (10,542 ) Other, including translation adjustments 2,366 Balance at end of period $ 12,997

Other Current Assets

Other Current Assets	12 Months Ended
	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Current Assets	Other Current Assets Other current assets consisted of the following (in thousands): December 31, 2018 2017 Deposits in trusts for employee deferred compensation plans $ 311,708 $ 292,326 Other 90,877 112,385 Other current assets $ 402,585 $ 404,711

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill The following table sets forth the activity in goodwill from December 31, 2016 , through December 31, 2018 (in thousands): Goodwill Temporary and consultant staffing Permanent placement staffing Risk consulting and internal audit services Total Balance as of December 31, 2016 $ 133,875 $ 26,015 $ 49,903 $ 209,793 Foreign currency translation adjustments 613 144 335 1,092 Balance as of December 31, 2017 $ 134,488 $ 26,159 $ 50,238 $ 210,885 Foreign currency translation adjustments (421 ) (101 ) (405 ) (927 ) Balance as of December 31, 2018 $ 134,067 $ 26,058 $ 49,833 $ 209,958

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and Equipment, Net Property and equipment consisted of the following (in thousands): December 31, 2018 2017 Computer hardware $ 177,237 $ 171,515 Computer software 378,734 376,761 Furniture and equipment 107,421 102,424 Leasehold improvements 160,521 148,764 Other 10,319 9,907 Property and equipment, cost 834,232 809,371 Accumulated depreciation (709,056 ) (664,484 ) Property and equipment, net $ 125,176 $ 144,887

Accrued Payroll and Benefit Cos

Accrued Payroll and Benefit Costs	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued Payroll and Benefit Costs	Accrued Payroll and Benefit Costs Accrued payroll and benefit costs consisted of the following (in thousands): December 31, 2018 2017 Payroll and benefits $ 263,072 $ 256,804 Employee deferred compensation plans 333,528 312,429 Workers’ compensation 18,251 17,092 Payroll taxes 23,918 26,574 Accrued payroll and benefit costs $ 638,769 $ 612,899 Included in employee deferred compensation plans is the following (in thousands): December 31, 2018 2017 Deferred compensation plan and other benefits related to the Company’s Chief Executive Officer $ 89,212 $ 86,145

Notes Payable and Other Indebte

Notes Payable and Other Indebtedness	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Notes Payable and Other Indebtedness	Notes Payable and Other Indebtedness The Company issued promissory notes as well as other forms of indebtedness in connection with certain acquisitions and other payment obligations. These notes are due in varying installments and, in aggregate, amounted to $0.7 million at December 31, 2018 , and $0.8 million at December 31, 2017 . At December 31, 2018 , $0.7 million of the notes were collateralized by a standby letter of credit. The following table shows the schedule of maturities for notes payable and other indebtedness at December 31, 2018 (in thousands): 2019 $ 200 2020 218 2021 239 2022 — 2023 — $ 657 At December 31, 2018 , the notes carried fixed rates and the weighted average interest rate for the above was 9.0% for each of the years ended December 31, 2018 , 2017 and 2016 . The Company has an uncommitted letter of credit facility (the “facility”) of up to $35.0 million , which is available to cover the issuance of debt support standby letters of credit. The Company had used $14.4 million in debt support standby letters of credit as of December 31, 2018 , and $17.4 million as of December 31, 2017 . Of the debt support standby letters of credit outstanding, $13.7 million as of December 31, 2018 , and $16.6 million as of December 31, 2017 , satisfies workers’ compensation insurer’s collateral requirements. There is a service fee of 1.125% on the used portion of the facility. The facility is subject to certain financial covenants and expires on August 31, 2019. The Company was in compliance with these covenants as of December 31, 2018 . The Company intends to renew this facility prior to its August 31, 2019 expiration.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The provision (benefit) for income taxes for the years ended December 31, 2018 , 2017 and 2016 , consisted of the following (in thousands): Years Ended December 31, 2018 2017 2016 Current: Federal $ 99,830 $ 133,097 $ 156,937 State 38,356 24,944 34,927 Foreign 35,007 27,079 20,725 Deferred: Federal and state (15,849 ) 41,717 (3,785 ) Foreign (30 ) 95 1,917 $ 157,314 $ 226,932 $ 210,721 Income before the provision for income taxes for the years ended December 31, 2018 , 2017 and 2016 , consisted of the following (in thousands): Years Ended December 31, 2018 2017 2016 Domestic $ 485,489 $ 445,418 $ 494,890 Foreign 106,113 72,098 59,220 $ 591,602 $ 517,516 $ 554,110 The income taxes shown above varied from the statutory federal income tax rates for these periods as follows: Years Ended December 31, 2018 2017 2016 Federal U.S. income tax rate 21.0 % 35.0 % 35.0 % State income taxes, net of federal tax benefit 4.7 3.7 4.2 Permanent book/tax differences 0.6 0.4 0.5 Non-U.S. income taxed at different rates, net of foreign tax credits 2.0 — (0.6 ) Federal tax credits (1.7 ) (1.3 ) (0.8 ) Tax impact of uncertain tax positions 0.8 0.2 — Valuation allowance release, net — — (0.1 ) Tax effects of TCJA 0.4 6.5 — Other, net (1.2 ) (0.6 ) (0.2 ) Effective tax rate 26.6 % 43.9 % 38.0 % The deferred portion of the tax (benefit) provision consisted of the following (in thousands): Years Ended December 31, 2018 2017 2016 Accrued expenses, deducted for tax when paid $ (21,884 ) $ 15,213 $ (6,889 ) Capitalized costs for books, deducted for tax (4,832 ) (5,790 ) 5,901 Depreciation 10,071 (4,079 ) (2,405 ) Tax effects of TCJA — 34,633 — Other, net 766 1,835 1,525 $ (15,879 ) $ 41,812 $ (1,868 ) The components of the deferred income tax amounts at December 31, 2018 and 2017 , were as follows (in thousands): December 31, 2018 2017 Deferred Income Tax Assets Deferred compensation and other benefit obligations $ 87,513 $ 68,101 Credits and net operating loss carryforwards 31,169 30,087 Stock-based compensation 9,535 8,614 Provision for bad debts 7,891 6,794 Workers’ compensation 3,580 3,127 Other 14,959 13,343 Total deferred income tax assets 154,647 130,066 Deferred Income Tax Liabilities Amortization of intangible assets (21,210 ) (20,220 ) Property and equipment basis differences (9,761 ) (4,421 ) Other (10,319 ) (10,847 ) Total deferred income tax liabilities (41,290 ) (35,488 ) Valuation allowance (23,072 ) (20,178 ) Total deferred income tax assets, net $ 90,285 $ 74,400 Credits and net operating loss carryforwards primarily include net operating losses in foreign countries of $27.7 million that expire in 2019 and later ; and California enterprise zone tax credits of $2.9 million that expire in 2023 . Of the $2.9 million of California enterprise zone tax credits, the Company expects that it will utilize $1.2 million of these credits prior to expiration. Valuation allowances of $21.4 million have been maintained against net operating loss carryforwards and other deferred items in foreign countries. In addition, a valuation allowance of $1.7 million has been maintained against California enterprise zone tax credits. As of December 31, 2018 , the Company’s consolidated financial statements provide for any related U.S. tax liability on earnings of foreign subsidiaries that may be repatriated, aside from undistributed earnings of certain of the Company’s foreign subsidiaries that are intended to be indefinitely reinvested in operations outside the United States. The following table reconciles the total amounts of gross unrecognized tax benefits from January 1, 2016 to December 31, 2018 (in thousands): December 31, 2018 2017 2016 Balance at beginning of period $ 2,886 $ 731 $ 814 Gross increases—tax positions in prior years 3,259 1,503 92 Gross decreases—tax positions in prior years (8 ) (257 ) — Gross increases—tax positions in current year 2,284 956 114 Settlements — (40 ) — Lapse of statute of limitations (3 ) (7 ) (289 ) Balance at end of period $ 8,418 $ 2,886 $ 731 The total amount of unrecognized tax benefits that, if recognized, would impact the effective tax rate is $8.3 million , $2.8 million and $0.5 million for 2018 , 2017 and 2016 , respectively. The Company’s continuing practice is to recognize interest and penalties related to income tax matters in income tax expense. The total amount of interest and penalties accrued as of December 31, 2018 is $0.3 million , including a $0.2 million increase recorded in income tax expense during the year. The total amount of interest and penalties accrued as of December 31, 2017 was $0.1 million . The total amount of interest and penalties accrued as of December 31, 2016 , was $0.1 million , including a $0.1 million reduction recorded in income tax expense during the year. The Company believes it is reasonably possible that the settlement of certain tax uncertainties could occur within the next twelve months; accordingly, $0.1 million of the unrecognized gross tax benefit has been classified as a current liability as of December 31, 2018 . This amount primarily represents unrecognized tax benefits composed of items related to assessed state income tax audits and negotiations. The Company’s major income tax jurisdictions are the United States, Australia, Belgium, Canada, France, Germany and the United Kingdom. For U.S. federal income tax, the Company remains subject to examination for 2015 and subsequent years. For major U.S. states, with few exceptions, the Company remains subject to examination for 2014 and subsequent years. Generally, for the foreign countries, the Company remains subject to examination for 2011 and subsequent years.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Rental expense, primarily for office premises, amounted to $89.4 million , $87.5 million and $87.3 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The approximate minimum rental commitments for 2019 and thereafter under non-cancelable leases in effect at December 31, 2018 were as follows (in thousands): 2019 $ 88,231 2020 81,252 2021 62,111 2022 47,268 2023 37,566 Thereafter 52,993 $ 369,421 On March 23, 2015, Plaintiff Jessica Gentry, on her own behalf and on behalf of a putative class of allegedly similarly situated individuals, filed a complaint against the Company in the Superior Court of California, San Francisco County, which was subsequently amended on October 23, 2015. The complaint alleges that a putative class of current and former employees of the Company working in California since March 13, 2010 were denied compensation for the time they spent interviewing “for temporary and permanent employment opportunities” as well as performing activities related to the interview process. Gentry seeks recovery on her own behalf and on behalf of the putative class in an unspecified amount for this allegedly unpaid compensation. Gentry also seeks recovery of an unspecified amount for the alleged failure of the Company to provide her and the putative class with accurate wage statements. Gentry also seeks an unspecified amount of other damages, attorneys’ fees, and statutory penalties, including penalties for allegedly not paying all wages due upon separation to former employees and statutory penalties on behalf of herself and other allegedly “aggrieved employees” as defined by California’s Labor Code Private Attorney General Act (“PAGA”). On January 4, 2016, the Court denied a motion by the Company to compel all of Gentry’s claims, except the PAGA claim, to individual arbitration. At this stage of the litigation, it is not feasible to predict the outcome of or a range of loss, should a loss occur, from this proceeding and, accordingly, no amounts have been provided in the Company’s Financial Statements. The Company believes it has meritorious defenses to the allegations and the Company intends to continue to vigorously defend against the litigation. On April 6, 2018, Plaintiff Shari Dorff, on her own behalf and on behalf of a putative class of allegedly similarly situated individuals, filed a complaint against the Company in the Superior Court of California, County of Los Angeles. In addition to certain claims individual to Plaintiff Dorff, the complaint alleges that salaried recruiters based in California have been misclassified as exempt employees and seeks an unspecified amount for: unpaid wages resulting from such alleged misclassification; alleged failure to provide a reasonable opportunity to take meal periods and rest breaks; alleged failure to pay wages on a timely basis both during employment and upon separation; alleged failure to comply with California requirements regarding wage statements and record-keeping; and alleged improper denial of expense reimbursement. Plaintiff Dorff also seeks an unspecified amount of other damages, attorneys’ fees, and penalties, including but not limited to statutory penalties on behalf of herself and other allegedly “aggrieved employees” as defined by PAGA. At this stage of the litigation, it is not feasible to predict the outcome of or a range of loss, should a loss occur, from this proceeding and, accordingly, no amounts have been provided in the Company’s Financial Statements. The Company believes it has meritorious defenses to the allegations and the Company intends to continue to vigorously defend against the litigation. The Company is involved in a number of other lawsuits arising in the ordinary course of business. While management does not expect any of these other matters to have a material adverse effect on the Company’s results of operations, financial position or cash flows, litigation is subject to certain inherent uncertainties. Legal costs associated with the resolution of claims, lawsuits and other contingencies are expensed as incurred.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Stock Repurchase Program. As of December 31, 2018 , the Company is authorized to repurchase, from time to time, up to 6.7 million additional shares of the Company’s common stock on the open market or in privately negotiated transactions, depending on market conditions. The number and the cost of common stock shares repurchased during the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table (in thousands): Years Ended December 31, 2018 2017 2016 Common stock repurchased (in shares) 5,614 4,046 4,046 Common stock repurchased $ 351,194 $ 196,645 $ 163,614 Additional stock repurchases were made in connection with employee stock plans, whereby Company shares were tendered by employees for the payment of exercise price and applicable statutory withholding taxes. The number and the cost of employee stock plan repurchases made during the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table (in thousands): Years Ended December 31, 2018 2017 2016 Repurchases related to employee stock plans (in shares) 235 408 359 Repurchases related to employee stock plans $ 13,674 $ 20,391 $ 15,170 The repurchased shares are held in treasury and are presented as if constructively retired. Treasury stock is accounted for using the cost method. Treasury stock activity for each of the three years ended December 31, 2018 , 2017 and 2016 (consisting of stock option exercises and the purchase of shares for the treasury) is presented in the Consolidated Statements of Stockholders’ Equity. Cash Dividends. The Company’s Board of Directors may at their discretion declare and pay dividends upon the shares of the Company’s stock either out of the Company’s retained earnings or capital surplus. The cash dividends declared during the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table: Years Ended December 31, 2018 2017 2016 Cash dividends declared per share $ 1.12 $ .96 $ .88 Repurchases of shares and issuances of cash dividends are applied first to the extent of retained earnings and any remaining amounts are applied to capital surplus. As a result, the Company had no retained earnings as of December 31, 2018 .

Stock Plans

Stock Plans	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Plans	Stock Plans Under various stock plans, officers, employees, and outside directors have received or may receive grants of restricted stock, stock units, stock appreciation rights or options to purchase common stock. Grants have been made at the discretion of the Committees of the Board of Directors. Grants generally vest either on a straight-line basis over four years or on a cliff basis over three years. Shares offered under the plan are authorized but unissued shares or treasury shares. Recipients of restricted stock do not pay any cash consideration to the Company for the shares, have the right to vote all shares subject to such grant, and there were no grants outstanding that received dividends prior to vesting. Restricted stock grants made on or after July 28, 2009, contain forfeitable rights to dividends. Dividends for these grants are accrued on the dividend payment dates but are not paid until the shares vest, and dividends accrued for shares that ultimately do not vest are forfeited. Recipients of stock units do not pay any cash consideration for the units, do not have the right to vote, and do not receive dividends with respect to such units. The Company recognizes compensation expense equal to the grant-date fair value for all stock-based payment awards that are expected to vest. This expense is recorded on a straight-line basis over the requisite service period of the entire award, unless the awards are subject to performance conditions, in which case the Company recognizes compensation expense over the requisite service period of each separate vesting tranche. The Company determines the grant-date fair value of its restricted stock and stock unit awards using the fair market value on the grant date, unless the awards are subject to market conditions, in which case the Company utilizes a binomial-lattice model (i.e., Monte Carlo simulation model). The Monte Carlo simulation model utilizes multiple input variables to determine the stock-based compensation expense. During the year ended December 31, 2018 , the Company granted performance shares to its executives in the form of restricted stock. The shares granted contain (1) a performance condition based on earnings per share, and (2) a performance condition based on Return on Invested Capital (“ROIC”). The ROIC performance condition measures the Company’s performance against a peer group. Shares will be delivered at the end of the three year vesting and ROIC performance period based on the Company’s actual performance compared to the peer group. Actual shares earned will range from seventy-five percent ( 75% ) to one hundred twenty-five percent ( 125% ) of the target award after any adjustment made for the EPS performance condition. Stock-based compensation expense consisted of the following (in thousands): Years Ended December 31, 2018 2017 2016 Restricted stock and stock units - expense $ 44,953 $ 42,191 $ 42,699 Unrecognized compensation cost is expected to be recognized over the next four years . Total unrecognized compensation cost, net of estimated forfeitures, consisted of the following (in thousands): December 31, 2018 2017 2016 Restricted stock and stock units - unrecognized future costs $ 65,557 $ 62,730 $ 60,481 The following table reflects activity under all stock plans from December 31, 2015 through December 31, 2018 , and the weighted average exercise prices (in thousands, except per share amounts): Restricted Stock Plans without Market-Condition Restricted Stock Plans with Market-Condition Stock Option Plans Number of Shares/ Units Weighted Average Grant Date Fair Value Number of Shares/ Units Weighted Average Grant Date Fair Value Number of Shares/ Units Weighted Average Exercise Price Per Share Outstanding, December 31, 2015 1,052 $46.88 992 $52.89 12 $32.36 Granted 772 $38.47 358 $45.93 — — Exercised — — — — (7 ) $32.36 Restrictions lapsed (545 ) $42.42 (364 ) $43.04 — — Forfeited (36 ) $41.28 (36 ) $43.04 (5 ) $32.36 Outstanding, December 31, 2016 1,243 $43.78 950 $54.42 — — Granted 904 $47.86 50 $50.09 — — Restrictions lapsed (616 ) $44.09 (384 ) $50.09 — — Forfeited (41 ) $43.68 — — — — Outstanding, December 31, 2017 1,490 $46.13 616 $56.76 — — Granted 811 $57.04 — — — — Restrictions lapsed (568 ) $47.62 (129 ) $71.86 — — Forfeited (40 ) $49.10 (129 ) $71.86 — — Outstanding, December 31, 2018 1,693 $50.78 358 $45.93 — — The total pre-tax intrinsic value of stock options exercised and the total fair value of shares vested during the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table (in thousands): Years Ended December 31, 2018 2017 2016 Total pre-tax intrinsic value of stock options exercised $ — $ — $ 52 Total fair value of shares vested $ 40,583 $ 50,385 $ 39,302 At December 31, 2018 , the total number of available shares to grant under the plans (consisting of either restricted stock, stock units, stock appreciation rights or options to purchase common stock) was approximately 3.2 million .

Net Income Per Share

Net Income Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Net Income Per Share	Net Income Per Share The calculation of net income per share for the three years ended December 31, 2018 is reflected in the following table (in thousands, except per share amounts): Years Ended December 31, 2018 2017 2016 Net income $ 434,288 $ 290,584 $ 343,389 Basic: Weighted average shares 120,513 124,152 127,991 Diluted: Weighted average shares 120,513 124,152 127,991 Dilutive effect of potential common shares 1,089 740 775 Diluted weighted average shares 121,602 124,892 128,766 Net income per share: Basic $ 3.60 $ 2.34 $ 2.68 Diluted $ 3.57 $ 2.33 $ 2.67 Potential common shares include the dilutive effect of stock options, unvested performance-based restricted stock, restricted stock which contains forfeitable rights to dividends, and stock units. Employee stock options will have a dilutive effect under the treasury method only when the respective period’s average market value of the Company’s common stock exceeds the exercise proceeds. Under the treasury method, exercise proceeds include the amount the employee must pay for exercising stock options, the amount of compensation cost for future service that the Company has not yet recognized, and the amount of tax benefits that would be recorded in capital surplus, if the options were exercised and the stock units and performance-based restricted stock had vested.

Business Segments

Business Segments	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Business Segments	Business Segments The Company has three reportable segments: temporary and consultant staffing, permanent placement staffing, and risk consulting and internal audit services. The temporary and consultant staffing segment provides specialized staffing in the accounting and finance, administrative and office, information technology, legal, advertising, marketing and web design fields. The permanent placement staffing segment provides full-time personnel in the accounting, finance, administrative and office, and information technology fields. The risk consulting and internal audit services segment provides business and technology risk consulting and internal audit services. The accounting policies of the segments are set forth in Note A—Summary of Significant Accounting Policies. The Company evaluates performance based on income from operations before net interest income, intangible amortization expense, and income taxes. The following table provides a reconciliation of revenue and operating income by reportable segment to consolidated results (in thousands): Years Ended December 31, 2018 2017 2016 Net service revenues Temporary and consultant staffing $ 4,330,566 $ 4,011,042 $ 4,026,777 Permanent placement staffing 511,989 439,214 419,314 Risk consulting and internal audit services 957,716 816,533 804,308 $ 5,800,271 $ 5,266,789 $ 5,250,399 Operating income Temporary and consultant staffing $ 404,800 $ 355,700 $ 393,704 Permanent placement staffing 90,801 77,673 80,001 Risk consulting and internal audit services 93,324 83,907 80,754 588,925 517,280 554,459 Amortization of intangible assets 1,705 1,563 1,237 Interest income, net (4,382 ) (1,799 ) (888 ) Income before income taxes $ 591,602 $ 517,516 $ 554,110 Assets by reportable segment are not presented as the Company does not allocate assets to its reportable segments, nor is such information used by management for purposes of assessing performance or allocating resources. The Company operates internationally, with operations in North America, South America, Europe, Asia and Australia. The following tables represent revenues and long-lived assets by geographic location (in thousands): Years Ended December 31, 2018 2017 2016 Net service revenues (a) Domestic $ 4,433,767 $ 4,121,701 $ 4,220,477 Foreign (b) 1,366,504 1,145,088 1,029,922 $ 5,800,271 $ 5,266,789 $ 5,250,399 December 31, 2018 2017 2016 Assets, long-lived Domestic $ 96,169 $ 113,069 $ 136,434 Foreign 29,007 31,818 25,075 $ 125,176 $ 144,887 $ 161,509 (a) There were no customers that accounted for more than 10% of the Company’s total net revenue in any year presented. (b) No individual country represented more than 10% of revenues in any year presented.

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	Quarterly Financial Data (Unaudited) The following tabulation shows certain quarterly financial data for 2018 and 2017 (in thousands, except per share amounts): Quarter 2018 1 2 3 4 Net service revenues $ 1,395,333 $ 1,457,054 $ 1,466,226 $ 1,481,658 Gross margin $ 572,366 $ 607,118 $ 610,468 $ 620,062 Income before income taxes $ 134,639 $ 150,075 $ 151,905 $ 154,983 Net income $ 96,167 $ 109,315 $ 115,242 $ 113,564 Basic net income per share $ .79 $ .90 $ .96 $ .96 Diluted net income per share $ .78 $ .89 $ .95 $ .95 Quarter 2017 1 2 3 4 Net service revenues $ 1,287,370 $ 1,308,428 $ 1,324,709 $ 1,346,282 Gross margin $ 525,828 $ 538,438 $ 546,400 $ 553,146 Income before income taxes $ 125,501 $ 130,707 $ 132,270 $ 129,038 Net income $ 78,521 $ 80,316 $ 84,700 $ 47,047 Basic net income per share $ .63 $ .64 $ .69 $ .38 Diluted net income per share $ .62 $ .64 $ .68 $ .38

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On February 12, 2019, the Company announced the following: Quarterly dividend per share $.31 Declaration date February 12, 2019 Record date February 25, 2019 Payment date March 15, 2019

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	Schedule II—Valuation and Qualifying Accounts (in thousands) Balance at Beginning of Period Charged to Expenses Deductions Translation Adjustments Balance at End of Period Year Ended December 31, 2016 Allowance for doubtful accounts receivable $ 35,087 9,192 (9,907 ) (1,239 ) $ 33,133 Deferred tax valuation allowance $ 26,329 2,160 (9,517 ) (65 ) $ 18,907 Year Ended December 31, 2017 Allowance for doubtful accounts receivable $ 33,133 8,022 (8,751 ) 777 $ 33,181 Deferred tax valuation allowance $ 18,907 1,411 (1,275 ) 1,135 $ 20,178 Year Ended December 31, 2018 Allowance for doubtful accounts receivable $ 23,682 (a) 11,914 (8,690 ) 772 $ 27,678 Deferred tax valuation allowance $ 20,178 5,683 (2,599 ) (190 ) $ 23,072 (a) In accordance with its adoption of ASC 606 Revenue from Contracts with Customers, on January 1, 2018 , the Company reclassified certain allowances that are now reflected as liabilities in the amount of $9.5 million .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation. The Consolidated Financial Statements (“Financial Statements”) of the Company are prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and the rules of the Securities and Exchange Commission (“SEC”).
Principles of Consolidation	Principles of Consolidation. The Financial Statements include the accounts of the Company and its subsidiaries, all of which are wholly owned. All intercompany balances have been eliminated.
Use of Estimates	Use of Estimates. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Such estimates also include allowances for uncollectible accounts receivable, sales adjustments and allowances, workers’ compensation losses, income and other taxes, and assumptions used in the Company's goodwill impairment assessment and in the valuation of stock grants subject to market conditions. Actual results and outcomes may differ from management's estimates and assumptions.
Revenue Recognition and Costs of Services	Revenue Recognition. The Company derives its revenues from three segments: temporary and consultant staffing, permanent placement staffing, and risk consulting and internal audit services. Net service revenues as presented on the Consolidated Statements of Operations represent services rendered to customers less sales adjustments and allowances. Reimbursements, including those related to travel and out-of-pocket expenses, are also included in net service revenues, and equivalent amounts of reimbursable expenses are included in direct costs of services. The Company records temporary and consultant staffing revenue on a gross basis as a principal versus on a net basis as an agent in the presentation of revenues and expenses. The Company has concluded that gross reporting is appropriate because the Company (i) has the risk of identifying and hiring qualified employees, (ii) has the discretion to select the employees and establish their price and duties and (iii) bears the risk for services that are not fully paid for by customers. Temporary and consultant staffing revenues—Temporary and consultant staffing revenues are recognized when the services are rendered by the Company’s temporary employees. Employees placed on temporary assignment by the Company are the Company’s legal employees while they are working on assignments. The Company pays all related costs of employment, including workers’ compensation insurance, state and federal unemployment taxes, social security and certain fringe benefits. The Company assumes the risk of acceptability of its employees to its customers. Permanent placement staffing revenues—Permanent placement staffing revenues are recognized when employment candidates accept offers of permanent employment. The Company has a substantial history of estimating the effect of permanent placement candidates who do not remain with its clients through the 90-day guarantee period. Allowances are established to estimate these losses. Fees to clients are generally calculated as a percentage of the new employee’s annual compensation. No fees for permanent placement services are charged to employment candidates. Risk consulting and internal audit revenues—Risk consulting and internal audit services are generally provided on a time-and-material basis or fixed-fee basis. Revenues earned under time-and-material arrangements and fixed-fee arrangements are recognized using a proportional performance method as hours are incurred relative to total estimated hours for the engagement. The Company periodically evaluates the need to provide for any losses on these projects, and losses are recognized when it is probable that a loss will be incurred. Costs of Services. Direct costs of temporary and consultant staffing consist of payroll, payroll taxes and benefit costs for the Company’s temporary employees, as well as reimbursable expenses. Direct costs of permanent placement staffing services consist of reimbursable expenses. Risk consulting and internal audit costs of services include professional staff payroll, payroll taxes and benefit costs, as well as reimbursable expenses.
Advertising Costs	Advertising Costs. The Company expenses all advertising costs as incurred.
Comprehensive Income	Comprehensive Income. Comprehensive income includes net income and certain other items that are recorded directly to Stockholders’ Equity. The Company’s only source of other comprehensive income is foreign currency translation adjustments.
Fair Value of Financial Instruments	Fair Value of Financial Instruments. The Company does not have any financial instruments which require re-measurement to fair value. The carrying values of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses represent fair value based upon their short-term nature.
Cash and Cash Equivalents	Cash and Cash Equivalents. The Company considers all highly liquid investments with a maturity at the date of purchase of three months or less as cash equivalents.
Accounts Receivable Allowances	Accounts Receivable Allowances. The Company maintains allowances for estimated losses resulting from (i) the inability of its customers to make required payments and (ii) sales adjustments. The Company establishes these allowances based on its review of customers’ credit profiles, historical loss statistics and current trends. The adequacy of these allowances is reviewed each reporting period. Historically, the Company’s actual losses have been consistent with these allowances.
Goodwill and Intangible Assets	Goodwill and Intangible Assets . Goodwill and intangible assets primarily consist of the cost of acquired companies in excess of the fair market value of their net tangible assets at the date of acquisition. Identifiable intangible assets are amortized over their lives, typically ranging from two to five years . Goodwill is not amortized, but is tested at least annually for impairment. The Company completed its annual goodwill impairment assessment as of June 30 in each of the three years ended December 31, 2018 , and determined that no adjustment to the carrying value of goodwill was required. There were no events or changes in circumstances during the six months ended December 31, 2018 that caused the Company to perform an interim impairment assessment.
Income Tax Assets and Liabilities	Income Taxes . The Company’s operations are subject to U.S. federal, state and local, and foreign income taxes. In establishing its deferred income tax assets and liabilities and its provision for income taxes, the Company makes judgments and interpretations based on the enacted tax laws that are applicable to its operations in various jurisdictions. Deferred tax assets and liabilities are measured and recorded using current enacted tax rates, which the Company expects will apply to taxable income in the years in which those temporary differences are recovered or settled. The likelihood of a material change in the Company’s expected realization of its deferred tax assets is dependent on future taxable income and the effectiveness of its tax planning strategies in the various relevant jurisdictions. On December 22, 2017, the President signed the Tax Cuts and Jobs Act (“TCJA”) into law. Effective January 1, 2018, among other changes, TCJA reduced the federal corporate tax rate to 21 percent, provided for a deemed repatriation and taxation at reduced rates of certain foreign earnings, and established new mechanisms to tax certain foreign earnings going forward. Similar to other large multinational companies, TCJA has wide ranging implications for the Company. In December 2017, the SEC issued Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act, which allowed the Company to record provisional amounts during a measurement period not to extend beyond one year of the enactment date. The Company completed its TCJA analysis and recorded its final adjustments, which were not material, in the fourth quarter of 2018. The Company also evaluates the need for valuation allowances to reduce the deferred tax assets to realizable amounts. Management evaluates all positive and negative evidence and uses judgment regarding past and future events, including operating results, to help determine when it is more likely than not that all or some portion of the deferred tax assets may not be realized. When appropriate, a valuation allowance is recorded against deferred tax assets to offset future tax benefits that may not be realized.
Workers' Compensation	Workers’ Compensation . Except for states which require participation in state-operated insurance funds, the Company retains the economic burden for the first $0.5 million per occurrence in workers’ compensation claims. Workers’ compensation includes ongoing healthcare and indemnity coverage for claims and may be paid over numerous years following the date of injury. Claims in excess of $0.5 million are insured. Workers’ compensation expense includes the insurance premiums for claims in excess of $0.5 million , claims administration fees charged by the Company’s workers’ compensation administrator, premiums paid to state-operated insurance funds, and an estimate for the Company’s liability for Incurred But Not Reported (“IBNR”) claims and for the ongoing development of existing claims. The reserves for IBNR claims and for the ongoing development of existing claims in each reporting period includes estimates. The Company has established reserves for workers’ compensation claims using loss development rates which are estimated using periodic third party actuarial valuations based upon historical loss statistics which include the Company’s historical frequency and severity of workers’ compensation claims, and an estimate of future cost trends. While management believes that its assumptions and estimates are appropriate, significant differences in actual experience or significant changes in assumptions may materially affect the Company’s future results.
Foreign Currency Translation	Foreign Currency Translation. The reporting currency of the Company and its subsidiaries is the U.S. dollar. The functional currency of the Company's foreign subsidiaries is their local currency. The results of operations of the Company’s foreign subsidiaries are translated at the monthly average exchange rates prevailing during the period. The financial position of the Company’s foreign subsidiaries is translated at the current exchange rates at the end of the period, and the related translation adjustments are recorded as a component of accumulated other comprehensive income within Stockholders’ Equity. Gains and losses resulting from foreign currency transactions are included as a component of selling, general and administrative expenses in the Consolidated Statements of Operations, and have not been material for all periods presented.
Stock-based Compensation	Stock-based Compensation . Under various stock plans, officers, employees and outside directors have received or may receive grants of restricted stock, stock units, stock appreciation rights or options to purchase common stock. The Company recognizes compensation expense equal to the grant-date fair value for all stock-based payment awards that are expected to vest. This expense is recorded on a straight-line basis over the requisite service period of the entire award, unless the awards are subject to performance conditions, in which case the Company recognizes compensation expense over the requisite service period of each separate vesting tranche. The Company determines the grant-date fair value of its restricted stock and stock unit awards using the fair market value of its stock on the grant date, unless the awards are subject to market conditions, in which case the Company utilizes a binomial-lattice model (i.e., Monte Carlo simulation model). The Monte Carlo simulation model utilizes multiple input variables to determine the stock-based compensation expense.
Property and Equipment	Property and Equipment . Property and equipment are recorded at cost. Depreciation expense is computed using the straight-line method over the following useful lives: Computer hardware 2 to 3 years Computer software 2 to 5 years Furniture and equipment 5 years Leasehold improvements Term of lease, 5 years maximum
Internal-use Software	Internal-use Software. The Company capitalizes direct costs incurred in the development of internal-use software. Amounts capitalized are reported as a component of computer software within property and equipment.
New Accounting Pronouncements	New Accounting Pronouncements Recently Adopted Accounting Pronouncements Revenue from Contracts with Customers. In May 2014, the Financial Accounting Standards Board (“FASB”) issued authoritative guidance that provides companies with a single model for use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance, including industry-specific revenue guidance. The new guidance requires a company to recognize revenue to depict the transfer of goods or services to a customer at an amount that reflects the consideration it expects to receive in exchange for those goods or services. The Company adopted the new guidance, using the modified retrospective method applied to all contracts not completed as of January 1, 2018, and since the adoption of the new guidance was not material, no adjustment was made to opening retained earnings. The Company also had no significant changes to systems, processes, or controls. The adoption of the guidance did not have a material impact on the Company’s income statement. In accordance with the new guidance, the Company reclassified certain allowances that are now reflected as liabilities. The impact to the Company’s balance sheet is as follows (in thousands): December 31, 2018 As Reported Balances Without Adoption of Revenue Guidance Effect of Change Higher (Lower) Assets Accounts receivable, net $ 794,446 $ 783,776 $ 10,670 Liabilities Accounts payable and accrued expenses $ 168,031 $ 157,361 $ 10,670 Stock Compensation. In May 2017, the FASB issued authoritative guidance updating which changes in the terms or conditions of a share-based payment award require an entity to apply modification accounting. Under the amended guidance, entities are required to account for the effects of a modification if the fair value, vesting conditions or classification (as an equity instrument or a liability instrument) of the modified award change from that of the original award immediately before the modification. The Company adopted the new guidance as of January 1, 2018. The adoption of this guidance did not have a material impact on the Company’s financial statements. Recently Issued Accounting Pronouncements Not Yet Adopted Lease Accounting . In February 2016, the FASB issued authoritative guidance which changes financial reporting as it relates to leasing transactions. Under the new guidance, lessees will be required to recognize a lease liability, measured on a discounted basis; and a right-of-use asset, for the lease term. Lessees and lessors may elect to apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements; or they may elect to apply the provisions of the guidance, using a prospective approach, beginning at the adoption date and recognize a cumulative effect adjustment to opening retained earnings in the period of adoption. The new standard was effective for the Company beginning January 1, 2019, and the Company implemented the new standard using a prospective approach. Upon adoption, the Company elected the package of practical expedients available under the new standard, which allowed the Company to forgo a reassessment of (1) whether any expired or existing contracts are or contain leases, (2) the lease classification for any expired or existing leases, and (3) the initial direct costs for any existing leases. The Company adopted this guidance as of January 1, 2019, using the transition method that allowed it to initially apply the guidance as of January 1, 2019, and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. This adjustment to the opening balance of retained earnings was not material. In addition to certain changes to its systems and processes, the estimated impact of the adoption of this guidance included the recognition of $270 million to $290 million of lease liabilities and right of use assets on the Company’s Consolidated Statement of Financial Position, offset by approximately $30 million of accrued rent, which reduced the right-of-use assets. Current Expected Credit Losses Model. In June 2016, the FASB issued authoritative guidance amending how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. The guidance requires the application of a current expected credit loss model, which is a new impairment model based on expected losses. The new guidance is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted for annual reporting periods beginning after December 15, 2018. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements and related disclosures. Simplifying the Test for Goodwill Impairment. In January 2017, the FASB issued authoritative guidance to simplify the goodwill impairment testing process. The new standard eliminates Step 2 of the goodwill impairment test. If a company determines in Step 1 of the goodwill impairment test that the carrying value of goodwill is greater than the fair value, an impairment in that amount should be recorded to the income statement, rather than proceeding to Step 2. The new guidance is effective for the Company for fiscal years beginning after December 15, 2019, although early adoption is permitted. The Company believes the adoption of this guidance will not have a material impact on its financial statements. Cloud Computing. In August 2018, the FASB issued authoritative guidance which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. Entities are required to present the expense related to capitalized implementation costs in the same line item in the statement of operations as the fees associated with the hosting elements of the arrangement and classify the payments for the capitalized implementation costs in the statement of cash flows in the same manner as payments made for fees associated with the hosting element. Entities are also required to present the capitalized implementation costs in the statement of financial position in the same line item that a prepayment of the fees of the associated hosting arrangement would be presented. The new guidance is effective for the Company for annual and interim periods beginning after December 15, 2019, although early adoption is permitted. The Company has adopted the new guidance as of January 1, 2019, and the impact of adoption was not material to its financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Advertising Costs	Advertising costs for the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table (in thousands): Years Ended December 31, 2018 2017 2016 Advertising Costs $ 52,499 $ 49,433 $ 47,312
Depreciation Expense Computed Using Straight-Line Method over Useful Lives	Depreciation expense is computed using the straight-line method over the following useful lives: Computer hardware 2 to 3 years Computer software 2 to 5 years Furniture and equipment 5 years Leasehold improvements Term of lease, 5 years maximum Property and equipment consisted of the following (in thousands): December 31, 2018 2017 Computer hardware $ 177,237 $ 171,515 Computer software 378,734 376,761 Furniture and equipment 107,421 102,424 Leasehold improvements 160,521 148,764 Other 10,319 9,907 Property and equipment, cost 834,232 809,371 Accumulated depreciation (709,056 ) (664,484 ) Property and equipment, net $ 125,176 $ 144,887
Internal-Use Software Development Costs Capitalized	Internal-use software development costs capitalized for the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table (in thousands): Years Ended December 31, 2018 2017 2016 Internal-use software development costs $ 3,287 $ 9,030 $ 33,753

New Accounting Pronouncements (

New Accounting Pronouncements (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Changes and Error Corrections [Abstract]
Schedule of Impact of Adoption	The impact to the Company’s balance sheet is as follows (in thousands): December 31, 2018 As Reported Balances Without Adoption of Revenue Guidance Effect of Change Higher (Lower) Assets Accounts receivable, net $ 794,446 $ 783,776 $ 10,670 Liabilities Accounts payable and accrued expenses $ 168,031 $ 157,361 $ 10,670

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Schedule of Revenue Disaggregated by Line of Business	The following table presents the Company’s revenues disaggregated by line of business (in thousands): Years Ended December 31, 2018 2017 2016 Accountemps $ 1,915,054 $ 1,765,666 $ 1,786,276 OfficeTeam 1,063,238 984,873 972,414 Robert Half Technology 682,889 629,278 659,844 Robert Half Management Resources 669,385 631,225 608,243 Temporary and consulting staffing 4,330,566 4,011,042 4,026,777 Permanent placement staffing 511,989 439,214 419,314 Risk consulting and internal audit services 957,716 816,533 804,308 Net service revenues $ 5,800,271 $ 5,266,789 $ 5,250,399
Schedule of Contract Liability Activity	The following table sets forth the activity in contract liabilities from January 1, 2018 through December 31, 2018 (in thousands): December 31, 2018 Balance at beginning of period $ 9,003 Payments in advance of satisfaction of performance obligations 12,170 Revenue recognized (10,542 ) Other, including translation adjustments 2,366 Balance at end of period $ 12,997

Other Current Assets (Tables)

Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Current Assets	Other current assets consisted of the following (in thousands): December 31, 2018 2017 Deposits in trusts for employee deferred compensation plans $ 311,708 $ 292,326 Other 90,877 112,385 Other current assets $ 402,585 $ 404,711

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Activity in Goodwill	The following table sets forth the activity in goodwill from December 31, 2016 , through December 31, 2018 (in thousands): Goodwill Temporary and consultant staffing Permanent placement staffing Risk consulting and internal audit services Total Balance as of December 31, 2016 $ 133,875 $ 26,015 $ 49,903 $ 209,793 Foreign currency translation adjustments 613 144 335 1,092 Balance as of December 31, 2017 $ 134,488 $ 26,159 $ 50,238 $ 210,885 Foreign currency translation adjustments (421 ) (101 ) (405 ) (927 ) Balance as of December 31, 2018 $ 134,067 $ 26,058 $ 49,833 $ 209,958

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Components of Property and Equipment	Depreciation expense is computed using the straight-line method over the following useful lives: Computer hardware 2 to 3 years Computer software 2 to 5 years Furniture and equipment 5 years Leasehold improvements Term of lease, 5 years maximum Property and equipment consisted of the following (in thousands): December 31, 2018 2017 Computer hardware $ 177,237 $ 171,515 Computer software 378,734 376,761 Furniture and equipment 107,421 102,424 Leasehold improvements 160,521 148,764 Other 10,319 9,907 Property and equipment, cost 834,232 809,371 Accumulated depreciation (709,056 ) (664,484 ) Property and equipment, net $ 125,176 $ 144,887

Accrued Payroll and Benefit C_2

Accrued Payroll and Benefit Costs (Tables)	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued Payroll and Benefit Costs	Accrued payroll and benefit costs consisted of the following (in thousands): December 31, 2018 2017 Payroll and benefits $ 263,072 $ 256,804 Employee deferred compensation plans 333,528 312,429 Workers’ compensation 18,251 17,092 Payroll taxes 23,918 26,574 Accrued payroll and benefit costs $ 638,769 $ 612,899
Employee Deferred Compensation Plans	Included in employee deferred compensation plans is the following (in thousands): December 31, 2018 2017 Deferred compensation plan and other benefits related to the Company’s Chief Executive Officer $ 89,212 $ 86,145

Notes Payable and Other Indeb_2

Notes Payable and Other Indebtedness (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of Maturities for Notes Payable and Other Indebtedness	The following table shows the schedule of maturities for notes payable and other indebtedness at December 31, 2018 (in thousands): 2019 $ 200 2020 218 2021 239 2022 — 2023 — $ 657

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Provision (Benefit) for Income Taxes	The provision (benefit) for income taxes for the years ended December 31, 2018 , 2017 and 2016 , consisted of the following (in thousands): Years Ended December 31, 2018 2017 2016 Current: Federal $ 99,830 $ 133,097 $ 156,937 State 38,356 24,944 34,927 Foreign 35,007 27,079 20,725 Deferred: Federal and state (15,849 ) 41,717 (3,785 ) Foreign (30 ) 95 1,917 $ 157,314 $ 226,932 $ 210,721
Income Before Provision for Income Taxes	Income before the provision for income taxes for the years ended December 31, 2018 , 2017 and 2016 , consisted of the following (in thousands): Years Ended December 31, 2018 2017 2016 Domestic $ 485,489 $ 445,418 $ 494,890 Foreign 106,113 72,098 59,220 $ 591,602 $ 517,516 $ 554,110
Difference of Income Taxes from Statutory Federal Income Tax Rates	The income taxes shown above varied from the statutory federal income tax rates for these periods as follows: Years Ended December 31, 2018 2017 2016 Federal U.S. income tax rate 21.0 % 35.0 % 35.0 % State income taxes, net of federal tax benefit 4.7 3.7 4.2 Permanent book/tax differences 0.6 0.4 0.5 Non-U.S. income taxed at different rates, net of foreign tax credits 2.0 — (0.6 ) Federal tax credits (1.7 ) (1.3 ) (0.8 ) Tax impact of uncertain tax positions 0.8 0.2 — Valuation allowance release, net — — (0.1 ) Tax effects of TCJA 0.4 6.5 — Other, net (1.2 ) (0.6 ) (0.2 ) Effective tax rate 26.6 % 43.9 % 38.0 %
Deferred Portion of Tax Provision (Benefit)	The deferred portion of the tax (benefit) provision consisted of the following (in thousands): Years Ended December 31, 2018 2017 2016 Accrued expenses, deducted for tax when paid $ (21,884 ) $ 15,213 $ (6,889 ) Capitalized costs for books, deducted for tax (4,832 ) (5,790 ) 5,901 Depreciation 10,071 (4,079 ) (2,405 ) Tax effects of TCJA — 34,633 — Other, net 766 1,835 1,525 $ (15,879 ) $ 41,812 $ (1,868 )
Components of Deferred Income Tax Amounts	The components of the deferred income tax amounts at December 31, 2018 and 2017 , were as follows (in thousands): December 31, 2018 2017 Deferred Income Tax Assets Deferred compensation and other benefit obligations $ 87,513 $ 68,101 Credits and net operating loss carryforwards 31,169 30,087 Stock-based compensation 9,535 8,614 Provision for bad debts 7,891 6,794 Workers’ compensation 3,580 3,127 Other 14,959 13,343 Total deferred income tax assets 154,647 130,066 Deferred Income Tax Liabilities Amortization of intangible assets (21,210 ) (20,220 ) Property and equipment basis differences (9,761 ) (4,421 ) Other (10,319 ) (10,847 ) Total deferred income tax liabilities (41,290 ) (35,488 ) Valuation allowance (23,072 ) (20,178 ) Total deferred income tax assets, net $ 90,285 $ 74,400
Reconciliation of Total Amounts of Gross Unrecognized Tax Benefits	The following table reconciles the total amounts of gross unrecognized tax benefits from January 1, 2016 to December 31, 2018 (in thousands): December 31, 2018 2017 2016 Balance at beginning of period $ 2,886 $ 731 $ 814 Gross increases—tax positions in prior years 3,259 1,503 92 Gross decreases—tax positions in prior years (8 ) (257 ) — Gross increases—tax positions in current year 2,284 956 114 Settlements — (40 ) — Lapse of statute of limitations (3 ) (7 ) (289 ) Balance at end of period $ 8,418 $ 2,886 $ 731

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Minimum Rental Commitments Under Non-Cancelable Leases	The approximate minimum rental commitments for 2019 and thereafter under non-cancelable leases in effect at December 31, 2018 were as follows (in thousands): 2019 $ 88,231 2020 81,252 2021 62,111 2022 47,268 2023 37,566 Thereafter 52,993 $ 369,421

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Number and Cost of Common Stock Shares Repurchased	The number and the cost of common stock shares repurchased during the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table (in thousands): Years Ended December 31, 2018 2017 2016 Common stock repurchased (in shares) 5,614 4,046 4,046 Common stock repurchased $ 351,194 $ 196,645 $ 163,614
Number and Cost of Employee Stock Plan Repurchases	The number and the cost of employee stock plan repurchases made during the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table (in thousands): Years Ended December 31, 2018 2017 2016 Repurchases related to employee stock plans (in shares) 235 408 359 Repurchases related to employee stock plans $ 13,674 $ 20,391 $ 15,170
Cash Dividends Declared	The cash dividends declared during the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table: Years Ended December 31, 2018 2017 2016 Cash dividends declared per share $ 1.12 $ .96 $ .88

Stock Plans (Tables)

Stock Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Expense	Stock-based compensation expense consisted of the following (in thousands): Years Ended December 31, 2018 2017 2016 Restricted stock and stock units - expense $ 44,953 $ 42,191 $ 42,699
Total Unrecognized Compensation Cost, Net of Estimated Forfeitures	Total unrecognized compensation cost, net of estimated forfeitures, consisted of the following (in thousands): December 31, 2018 2017 2016 Restricted stock and stock units - unrecognized future costs $ 65,557 $ 62,730 $ 60,481
Activity Under All Stock Plans and Weighted Average Exercise Prices	The following table reflects activity under all stock plans from December 31, 2015 through December 31, 2018 , and the weighted average exercise prices (in thousands, except per share amounts): Restricted Stock Plans without Market-Condition Restricted Stock Plans with Market-Condition Stock Option Plans Number of Shares/ Units Weighted Average Grant Date Fair Value Number of Shares/ Units Weighted Average Grant Date Fair Value Number of Shares/ Units Weighted Average Exercise Price Per Share Outstanding, December 31, 2015 1,052 $46.88 992 $52.89 12 $32.36 Granted 772 $38.47 358 $45.93 — — Exercised — — — — (7 ) $32.36 Restrictions lapsed (545 ) $42.42 (364 ) $43.04 — — Forfeited (36 ) $41.28 (36 ) $43.04 (5 ) $32.36 Outstanding, December 31, 2016 1,243 $43.78 950 $54.42 — — Granted 904 $47.86 50 $50.09 — — Restrictions lapsed (616 ) $44.09 (384 ) $50.09 — — Forfeited (41 ) $43.68 — — — — Outstanding, December 31, 2017 1,490 $46.13 616 $56.76 — — Granted 811 $57.04 — — — — Restrictions lapsed (568 ) $47.62 (129 ) $71.86 — — Forfeited (40 ) $49.10 (129 ) $71.86 — — Outstanding, December 31, 2018 1,693 $50.78 358 $45.93 — —
Pre-Tax Intrinsic Value of Stock Option Exercised	The total pre-tax intrinsic value of stock options exercised and the total fair value of shares vested during the years ended December 31, 2018 , 2017 and 2016 , are reflected in the following table (in thousands): Years Ended December 31, 2018 2017 2016 Total pre-tax intrinsic value of stock options exercised $ — $ — $ 52 Total fair value of shares vested $ 40,583 $ 50,385 $ 39,302

Net Income Per Share (Tables)

Net Income Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Calculation of Net Income Per Share	The calculation of net income per share for the three years ended December 31, 2018 is reflected in the following table (in thousands, except per share amounts): Years Ended December 31, 2018 2017 2016 Net income $ 434,288 $ 290,584 $ 343,389 Basic: Weighted average shares 120,513 124,152 127,991 Diluted: Weighted average shares 120,513 124,152 127,991 Dilutive effect of potential common shares 1,089 740 775 Diluted weighted average shares 121,602 124,892 128,766 Net income per share: Basic $ 3.60 $ 2.34 $ 2.68 Diluted $ 3.57 $ 2.33 $ 2.67

Business Segments (Tables)

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Reconciliation of Revenue and Operating Income by Reportable Segment to Consolidated Results	The following table provides a reconciliation of revenue and operating income by reportable segment to consolidated results (in thousands): Years Ended December 31, 2018 2017 2016 Net service revenues Temporary and consultant staffing $ 4,330,566 $ 4,011,042 $ 4,026,777 Permanent placement staffing 511,989 439,214 419,314 Risk consulting and internal audit services 957,716 816,533 804,308 $ 5,800,271 $ 5,266,789 $ 5,250,399 Operating income Temporary and consultant staffing $ 404,800 $ 355,700 $ 393,704 Permanent placement staffing 90,801 77,673 80,001 Risk consulting and internal audit services 93,324 83,907 80,754 588,925 517,280 554,459 Amortization of intangible assets 1,705 1,563 1,237 Interest income, net (4,382 ) (1,799 ) (888 ) Income before income taxes $ 591,602 $ 517,516 $ 554,110
Revenue and Long-Lived Assets by Geographic Location	The following tables represent revenues and long-lived assets by geographic location (in thousands): Years Ended December 31, 2018 2017 2016 Net service revenues (a) Domestic $ 4,433,767 $ 4,121,701 $ 4,220,477 Foreign (b) 1,366,504 1,145,088 1,029,922 $ 5,800,271 $ 5,266,789 $ 5,250,399 December 31, 2018 2017 2016 Assets, long-lived Domestic $ 96,169 $ 113,069 $ 136,434 Foreign 29,007 31,818 25,075 $ 125,176 $ 144,887 $ 161,509 (a) There were no customers that accounted for more than 10% of the Company’s total net revenue in any year presented. (b) No individual country represented more than 10% of revenues in any year presented.

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	The following tabulation shows certain quarterly financial data for 2018 and 2017 (in thousands, except per share amounts): Quarter 2018 1 2 3 4 Net service revenues $ 1,395,333 $ 1,457,054 $ 1,466,226 $ 1,481,658 Gross margin $ 572,366 $ 607,118 $ 610,468 $ 620,062 Income before income taxes $ 134,639 $ 150,075 $ 151,905 $ 154,983 Net income $ 96,167 $ 109,315 $ 115,242 $ 113,564 Basic net income per share $ .79 $ .90 $ .96 $ .96 Diluted net income per share $ .78 $ .89 $ .95 $ .95 Quarter 2017 1 2 3 4 Net service revenues $ 1,287,370 $ 1,308,428 $ 1,324,709 $ 1,346,282 Gross margin $ 525,828 $ 538,438 $ 546,400 $ 553,146 Income before income taxes $ 125,501 $ 130,707 $ 132,270 $ 129,038 Net income $ 78,521 $ 80,316 $ 84,700 $ 47,047 Basic net income per share $ .63 $ .64 $ .69 $ .38 Diluted net income per share $ .62 $ .64 $ .68 $ .38

Subsequent Events (Tables)

Subsequent Events (Tables)	12 Months Ended
	Dec. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	On February 12, 2019, the Company announced the following: Quarterly dividend per share $.31 Declaration date February 12, 2019 Record date February 25, 2019 Payment date March 15, 2019

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018USD ($)segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Accounting Policies [Abstract]
Number of reportable segments | segment	3
Advertising Costs	$ 52,499,000	$ 49,433,000	$ 47,312,000
Goodwill [Line Items]
Valuation allowance	23,072,000	$ 20,178,000
Provision for workers' compensation claims threshold	$ 500,000
Minimum
Goodwill [Line Items]
Amortized life assigned to identifiable intangible assets (in years)	2 years
Maximum
Goodwill [Line Items]
Amortized life assigned to identifiable intangible assets (in years)	5 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Property Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2018
Computer hardware | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years
Computer hardware | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Computer software | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years
Computer software | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Internal Use Software (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Internal-use software development costs	$ 3,287	$ 9,030	$ 33,753

New Accounting Pronouncements -

New Accounting Pronouncements - Schedule of Impact of Adoption (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net		$ 794,446	$ 732,405
Accounts payable and accrued expenses		168,031	$ 126,937
Accounting Standards Update 2016-02 | Scenario, Forecast | Subsequent Event
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accrued Rent	$ 30,000
Accounting Standards Update 2016-02 | Scenario, Forecast | Minimum | Subsequent Event
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liabilities	270,000
Right-of-use asset	270,000
Accounting Standards Update 2016-02 | Scenario, Forecast | Maximum | Subsequent Event
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liabilities	290,000
Right-of-use asset	$ 290,000
Balances Without Adoption of Revenue Guidance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net		783,776
Accounts payable and accrued expenses		157,361
Effect of Change Higher (Lower) | Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net		10,670
Accounts payable and accrued expenses		$ 10,670

Revenue Recognition - Schedule

Revenue Recognition - Schedule of Revenue Disaggregated by Line of Business (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2018USD ($)segment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Revenue from Contract with Customer [Abstract]
Number of reportable segments | segment									3
Guarantee period									90 days
Disaggregation of Revenue [Line Items]
Net service revenues	$ 1,481,658	$ 1,466,226	$ 1,457,054	$ 1,395,333	$ 1,346,282	$ 1,324,709	$ 1,308,428	$ 1,287,370	$ 5,800,271	$ 5,266,789	$ 5,250,399
Accountemps
Disaggregation of Revenue [Line Items]
Net service revenues									1,915,054	1,765,666	1,786,276
OfficeTeam
Disaggregation of Revenue [Line Items]
Net service revenues									1,063,238	984,873	972,414
Robert Half Technology
Disaggregation of Revenue [Line Items]
Net service revenues									682,889	629,278	659,844
Robert Half Management Resources
Disaggregation of Revenue [Line Items]
Net service revenues									669,385	631,225	608,243
Temporary and consulting staffing
Disaggregation of Revenue [Line Items]
Net service revenues									4,330,566	4,011,042	4,026,777
Permanent placement staffing
Disaggregation of Revenue [Line Items]
Net service revenues									511,989	439,214	419,314
Risk consulting and internal audit services
Disaggregation of Revenue [Line Items]
Net service revenues									$ 957,716	$ 816,533	$ 804,308

Revenue Recognition - Remaining

Revenue Recognition - Remaining Performance Obligation (Details)	12 Months Ended
	Dec. 31, 2018USD ($)
Revenue from Contract with Customer [Abstract]
Aggregate transaction price allocated to performance obligations	$ 58,800,000
Revenue recognized related to performance obligation	0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue from Contract with Customer [Abstract]
Aggregate transaction price allocated to performance obligations	$ 54,900,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, expected duration	12 months

Revenue Recognition - Schedul_2

Revenue Recognition - Schedule of Contract Liability Activity (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Change in Contract with Customer, Liability [Abstract]
Balance at beginning of period	$ 9,003
Payments in advance of satisfaction of performance obligations	12,170
Revenue recognized	(10,542)
Other, including translation adjustments	(2,366)
Balance at end of period	$ 12,997

Other Current Assets (Details)

Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deposits in trusts for employee deferred compensation plans	$ 311,708	$ 292,326
Other	90,877	112,385
Other current assets	$ 402,585	$ 404,711

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Beginning balance	$ 210,885	$ 209,793
Foreign currency translation adjustments	(927)	1,092
Ending balance	209,958	210,885
Temporary and consultant staffing
Goodwill [Roll Forward]
Beginning balance	134,488	133,875
Foreign currency translation adjustments	(421)	613
Ending balance	134,067	134,488
Permanent placement staffing
Goodwill [Roll Forward]
Beginning balance	26,159	26,015
Foreign currency translation adjustments	(101)	144
Ending balance	26,058	26,159
Risk consulting and internal audit services
Goodwill [Roll Forward]
Beginning balance	50,238	49,903
Foreign currency translation adjustments	(405)	335
Ending balance	$ 49,833	$ 50,238

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, cost	$ 834,232	$ 809,371
Accumulated depreciation	(709,056)	(664,484)
Property and equipment, net	125,176	144,887	$ 161,509
Computer hardware
Property, Plant and Equipment [Line Items]
Property and equipment, cost	177,237	171,515
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment, cost	378,734	376,761
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, cost	107,421	102,424
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, cost	160,521	148,764
Other
Property, Plant and Equipment [Line Items]
Property and equipment, cost	$ 10,319	$ 9,907

Accrued Payroll and Benefit C_3

Accrued Payroll and Benefit Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Payroll and benefits	$ 263,072	$ 256,804
Employee deferred compensation plans	333,528	312,429
Workers’ compensation	18,251	17,092
Payroll taxes	23,918	26,574
Accrued payroll and benefit costs	638,769	612,899
Chief Executive Officer
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred compensation plan and other benefits related to the Company’s Chief Executive Officer	$ 89,212	$ 86,145

Notes Payable and Other Indeb_3

Notes Payable and Other Indebtedness - Additional Information (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Promissory notes and other forms of indebtedness, issued	$ 700,000	$ 800,000
Weighted average interest rate	9.00%	9.00%	9.00%
Uncommitted letter of credit facility	$ 35,000,000
Debt support standby letters of credit	$ 14,400,000	$ 17,400,000
Service fee percentage	1.125%
Standby letter of credit
Debt Instrument [Line Items]
Promissory notes and other forms of indebtedness collateralized	$ 700,000
Standby letters of credit used for collateral requirements
Debt Instrument [Line Items]
Letters of credit outstanding	$ 13,700,000	$ 16,600,000

Notes Payable and Other Indeb_4

Notes Payable and Other Indebtedness - Schedule of Maturities for Notes Payable and Other Indebtedness (Details) $ in Thousands	Dec. 31, 2018USD ($)
Debt Disclosure [Abstract]
2,019	$ 200
2,020	218
2,021	239
2,022	0
2,023	0
Notes payable and other indebtedness	$ 657

Income Taxes - Provision for In

Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ 99,830	$ 133,097	$ 156,937
State	38,356	24,944	34,927
Foreign	35,007	27,079	20,725
Deferred:
Federal and state	(15,849)	41,717	(3,785)
Foreign	(30)	95	1,917
Provision (benefit) for income taxes	$ 157,314	$ 226,932	$ 210,721

Income Taxes - Income Before Pr

Income Taxes - Income Before Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Domestic									$ 485,489	$ 445,418	$ 494,890
Foreign									106,113	72,098	59,220
Income before income taxes	$ 154,983	$ 151,905	$ 150,075	$ 134,639	$ 129,038	$ 132,270	$ 130,707	$ 125,501	$ 591,602	$ 517,516	$ 554,110

Income Taxes - Difference of In

Income Taxes - Difference of Income Taxes from Statutory Federal Income Tax Rates (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal U.S. income tax rate	21.00%	35.00%	35.00%
State income taxes, net of federal tax benefit	4.70%	3.70%	4.20%
Permanent book/tax differences	0.60%	0.40%	0.50%
Non-U.S. income taxed at different rates, net of foreign tax credits	2.00%	(0.00%)	(0.60%)
Federal tax credits	(1.70%)	(1.30%)	(0.80%)
Tax impact of uncertain tax positions	0.80%	0.20%	0.00%
Valuation allowance release, net	0.00%	0.00%	(0.10%)
Tax effects of TCJA	0.40%	6.50%	0.00%
Other, net	(1.20%)	(0.60%)	(0.20%)
Effective tax rate	26.60%	43.90%	38.00%

Income Taxes - Deferred Portion

Income Taxes - Deferred Portion of Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Accrued expenses, deducted for tax when paid	$ (21,884)	$ 15,213	$ (6,889)
Capitalized costs for books, deducted for tax	(4,832)	(5,790)	5,901
Depreciation	10,071	(4,079)	(2,405)
Tax effects of TCJA	0	34,633	0
Other, net	766	1,835	1,525
Deferred portion of the tax provision (benefit)	$ (15,879)	$ 41,812	$ (1,868)

Income Taxes - Components of De

Income Taxes - Components of Deferred Income Tax Amounts (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Income Tax Assets
Deferred compensation and other benefit obligations	$ 87,513	$ 68,101
Credits and net operating loss carryforwards	31,169	30,087
Stock-based compensation	9,535	8,614
Provision for bad debts	7,891	6,794
Workers’ compensation	3,580	3,127
Other	14,959	13,343
Total deferred income tax assets	154,647	130,066
Deferred Income Tax Liabilities
Amortization of intangible assets	(21,210)	(20,220)
Property and equipment basis differences	(9,761)	(4,421)
Other	(10,319)	(10,847)
Total deferred income tax liabilities	(41,290)	(35,488)
Valuation allowance	(23,072)	(20,178)
Total deferred income tax assets, net	$ 90,285	$ 74,400

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2016	Dec. 31, 2017
Income Taxes [Line Items]
Amount expected to be utilized of tax credit carry forwards expiring in the and beyond the stated year	$ 1,200
Valuation allowance	23,072		$ 20,178
Unrecognized tax benefits, impact on effective tax rate	8,300	$ 500	2,800
Accrued interest and penalties	300	100	$ 100
Increase (decrease) in income tax expense	200	$ (100)
Unrecognized tax benefits, gross	100
Foreign Countries
Income Taxes [Line Items]
Valuation allowance	21,400
Foreign Countries
Income Taxes [Line Items]
Net operating loss carryforwards, foreign	27,700
California enterprise zone
Income Taxes [Line Items]
California enterprise zone tax credits	2,900
California enterprise zone | California Enterprise Zone
Income Taxes [Line Items]
Valuation allowance	$ 1,700

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Total Amounts of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$ 2,886	$ 731	$ 814
Gross increases—tax positions in prior years	3,259	1,503	92
Gross decreases—tax positions in prior years	(8)	(257)	0
Gross increases—tax positions in current year	2,284	956	114
Settlements	0	(40)	0
Lapse of statute of limitations	(3)	(7)	(289)
Balance at end of period	$ 8,418	$ 2,886	$ 731

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Rental expense	$ 89,400,000	$ 87,500,000	$ 87,300,000
Gentry Case
Loss Contingencies [Line Items]
Allegations loss	$ 0

Commitments and Contingencies_2

Commitments and Contingencies - Minimum Rental Commitments Under Non-Cancelable Leases (Details) $ in Thousands	Dec. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 88,231
2,020	81,252
2,021	62,111
2,022	47,268
2,023	37,566
Thereafter	52,993
Minimum payments due	$ 369,421

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($) shares in Millions	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Shares remaining under existing repurchase program	6.7
Retained earnings	$ 0	$ 37,033,000

Stockholders' Equity - Number o

Stockholders' Equity - Number of Cost of Common Stock Shares Repurchased (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Common stock repurchased (in shares)	5,614	4,046	4,046
Common stock repurchased	$ 351,194	$ 196,645	$ 163,614

Stockholders' Equity - Number a

Stockholders' Equity - Number and Cost of Employee Stock Plan Repurchases (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Repurchases related to employee stock plans (in shares)	235	408	359
Repurchases related to employee stock plans	$ 13,674	$ 20,391	$ 15,170

Stockholders' Equity - Cash Div

Stockholders' Equity - Cash Dividends Declared (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Cash dividends declared per share (usd per share)	$ 1.12	$ 0.96	$ 0.88

Stock Plans - Additional Inform

Stock Plans - Additional Information (Details) shares in Millions	12 Months Ended
	Dec. 31, 2018shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for grants (in years)	3 years
Unrecognized compensation cost expected to be recognized over the period (years)	4 years
Total number of available shares to grant	3.2
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Actual shares earned, possible percentage on target award	75.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Actual shares earned, possible percentage on target award	125.00%
Restricted stock and stock units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for grants (in years)	3 years
Restricted stock and stock units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for grants (in years)	4 years

Stock Plans - Stock-Based Compe

Stock Plans - Stock-Based Compensation Expense (Details) - Restricted stock and stock units - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 44,953	$ 42,191	$ 42,699
Total unrecognized compensation cost, net of estimated forfeitures	$ 65,557	$ 62,730	$ 60,481

Stock Plans - Activity Under Al

Stock Plans - Activity Under All Stock Plans and Weighted Average Exercise Prices (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Options, Number of Shares/Units:
Outstanding Beginning Balance (in shares)	0	0	12
Granted (in shares)	0	0	0
Exercised (in shares)			(7)
Restrictions lapsed (in shares)	0	0	0
Forfeited (in shares)	0	0	(5)
Outstanding, Ending Balance (in shares)	0	0	0
Weighted Average Exercise Price Per Share:
Outstanding Beginning Balance (usd per share)	$ 0	$ 0	$ 32.36
Granted (usd per share)	0	0	0
Exercised (usd per share)			32.36
Restrictions lapsed (usd per share)	0	0	0
Forfeited (usd per share)	0	0	32.36
Outstanding Ending Balance (usd per share)	$ 0	$ 0	$ 0
Restricted stock and stock units | Restricted Stock Plans without Market-Condition
Number of Shares/Units:
Outstanding Beginning Balance (in shares)	1,490	1,243	1,052
Granted (in shares)	811	904	772
Exercised (in shares)			0
Restrictions lapsed (in shares)	(568)	(616)	(545)
Forfeited (in shares)	(40)	(41)	(36)
Outstanding, Ending Balance (in shares)	1,693	1,490	1,243
Weighted Average Grant Date Fair Value:
Outstanding Beginning Balance (usd per share)	$ 46.13	$ 43.78	$ 46.88
Granted (usd per share)	57.04	47.86	38.47
Exercised (usd per share)			0
Restrictions lapsed (usd per share)	47.62	44.09	42.42
Forfeited (usd per share)	49.10	43.68	41.28
Outstanding Ending Balance (usd per share)	$ 50.78	$ 46.13	$ 43.78
Restricted stock and stock units | Restricted Stock Plans with Market-Condition
Number of Shares/Units:
Outstanding Beginning Balance (in shares)	616	950	992
Granted (in shares)	0	50	358
Exercised (in shares)			0
Restrictions lapsed (in shares)	(129)	(384)	(364)
Forfeited (in shares)	(129)	0	(36)
Outstanding, Ending Balance (in shares)	358	616	950
Weighted Average Grant Date Fair Value:
Outstanding Beginning Balance (usd per share)	$ 56.76	$ 54.42	$ 52.89
Granted (usd per share)	0	50.09	45.93
Exercised (usd per share)			0
Restrictions lapsed (usd per share)	71.86	50.09	43.04
Forfeited (usd per share)	71.86	0	43.04
Outstanding Ending Balance (usd per share)	$ 45.93	$ 56.76	$ 54.42

Stock Plans - Total Pre-Tax Int

Stock Plans - Total Pre-Tax Intrinsic Value of Stock Options Exercised and Total Fair Value of Shares Vested (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Total pre-tax intrinsic value of stock options exercised	$ 0	$ 0	$ 52
Total fair value of shares vested	$ 40,583	$ 50,385	$ 39,302

Net Income Per Share - Calculat

Net Income Per Share - Calculation of Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income	$ 113,564	$ 115,242	$ 109,315	$ 96,167	$ 47,047	$ 84,700	$ 80,316	$ 78,521	$ 434,288	$ 290,584	$ 343,389
Basic:
Weighted average shares (in shares)									120,513	124,152	127,991
Diluted:
Weighted average shares (in shares)									120,513	124,152	127,991
Dilutive effect of potential common shares (in shares)									1,089	740	775
Diluted weighted average shares (in shares)									121,602	124,892	128,766
Net income per share:
Basic (usd per share)	$ 0.96	$ 0.96	$ 0.90	$ 0.79	$ 0.38	$ 0.69	$ 0.64	$ 0.63	$ 3.60	$ 2.34	$ 2.68
Diluted (usd per share)	$ 0.95	$ 0.95	$ 0.89	$ 0.78	$ 0.38	$ 0.68	$ 0.64	$ 0.62	$ 3.57	$ 2.33	$ 2.67

Business Segments - Additional

Business Segments - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018segment
Segment Reporting [Abstract]
Number of reportable segments	3

Business Segments - Reconciliat

Business Segments - Reconciliation of Revenue and Operating Income by Reportable Segment to Consolidated Results (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net service revenues	$ 1,481,658	$ 1,466,226	$ 1,457,054	$ 1,395,333	$ 1,346,282	$ 1,324,709	$ 1,308,428	$ 1,287,370	$ 5,800,271	$ 5,266,789	$ 5,250,399
Operating income									588,925	517,280	554,459
Amortization of intangible assets									1,705	1,563	1,237
Interest income, net									(4,382)	(1,799)	(888)
Income before income taxes	$ 154,983	$ 151,905	$ 150,075	$ 134,639	$ 129,038	$ 132,270	$ 130,707	$ 125,501	591,602	517,516	554,110
Temporary and consultant staffing
Segment Reporting Information [Line Items]
Net service revenues									4,330,566	4,011,042	4,026,777
Operating income									404,800	355,700	393,704
Permanent placement staffing
Segment Reporting Information [Line Items]
Net service revenues									511,989	439,214	419,314
Operating income									90,801	77,673	80,001
Risk consulting and internal audit services
Segment Reporting Information [Line Items]
Net service revenues									957,716	816,533	804,308
Operating income									$ 93,324	$ 83,907	$ 80,754

Business Segments - Revenue and

Business Segments - Revenue and Long-Lived Assets by Geographic Location (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Net service revenues	$ 1,481,658	$ 1,466,226	$ 1,457,054	$ 1,395,333	$ 1,346,282	$ 1,324,709	$ 1,308,428	$ 1,287,370	$ 5,800,271	$ 5,266,789	$ 5,250,399
Assets, long-lived	125,176				144,887				125,176	144,887	161,509
Domestic
Revenues from External Customers and Long-Lived Assets [Line Items]
Net service revenues									4,433,767	4,121,701	4,220,477
Assets, long-lived	96,169				113,069				96,169	113,069	136,434
Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Net service revenues									1,366,504	1,145,088	1,029,922
Assets, long-lived	$ 29,007				$ 31,818				$ 29,007	$ 31,818	$ 25,075

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Net service revenues	$ 1,481,658	$ 1,466,226	$ 1,457,054	$ 1,395,333	$ 1,346,282	$ 1,324,709	$ 1,308,428	$ 1,287,370	$ 5,800,271	$ 5,266,789	$ 5,250,399
Gross margin	620,062	610,468	607,118	572,366	553,146	546,400	538,438	525,828	2,410,014	2,163,812	2,160,676
Income before income taxes	154,983	151,905	150,075	134,639	129,038	132,270	130,707	125,501	591,602	517,516	554,110
Net income	$ 113,564	$ 115,242	$ 109,315	$ 96,167	$ 47,047	$ 84,700	$ 80,316	$ 78,521	$ 434,288	$ 290,584	$ 343,389
Basic net income per share (in USD per share)	$ 0.96	$ 0.96	$ 0.90	$ 0.79	$ 0.38	$ 0.69	$ 0.64	$ 0.63	$ 3.60	$ 2.34	$ 2.68
Diluted net income per share (in USD per share)	$ 0.95	$ 0.95	$ 0.89	$ 0.78	$ 0.38	$ 0.68	$ 0.64	$ 0.62	$ 3.57	$ 2.33	$ 2.67

Subsequent Events (Details)

Subsequent Events (Details) - $ / shares	Feb. 12, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Quarterly dividend per share (usd per share)		$ 1.12	$ 0.96	$ 0.88
Declaration date		Feb. 12, 2019
Record date		Feb. 25, 2019
Payment date		Mar. 15, 2019
Subsequent Event
Subsequent Event [Line Items]
Quarterly dividend per share (usd per share)	$ 0.31

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Allowance for doubtful accounts receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 33,181	$ 33,133	$ 35,087
Charged to Expenses	11,914	8,022	9,192
Deductions	(8,690)	(8,751)	(9,907)
Translation Adjustments	772	777	(1,239)
Balance at End of Period	27,678	33,181	33,133
Liability recognized in accordance with ASC 606	(33,181)	(33,133)	(35,087)	$ (23,682)
Allowance for doubtful accounts receivable | Accounting Standards Update 2014-09
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Liability recognized in accordance with ASC 606				$ 9,500
Deferred tax valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	20,178	18,907	26,329
Charged to Expenses	5,683	1,411	2,160
Deductions	(2,599)	(1,275)	(9,517)
Translation Adjustments	(190)	1,135	(65)
Balance at End of Period	23,072	20,178	18,907
Liability recognized in accordance with ASC 606	$ (20,178)	$ (18,907)	$ (26,329)