ASGN (ASGN) 10-Q 9 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares shares in Millions	3 Months Ended
	Mar. 31, 2019	May 02, 2019
Entity Information [Line Items]
Document Type	10-Q
Entity Registrant Name	ASGN Inc
Trading Symbol	ASGN
Entity Listing, Description	NYSE
Entity Central Index Key	0000890564
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		52.8

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 35.6	$ 41.8
Accounts receivable, net	618.7	613.8
Prepaid expenses and income taxes	16.9	11.4
Workers' compensation receivable	15.2	15
Other current assets	5	4.3
Total current assets	691.4	686.3
Property and equipment, net	77	79.1
Operating lease right of use assets	91.4	0
Identifiable intangible assets, net	493.4	488.7
Goodwill	1,445.5	1,421.1
Other non-current assets	15.9	12.6
Total assets	2,814.6	2,687.8
Current liabilities:
Accounts payable	27.8	43.1
Accrued payroll and contract professional pay	188.2	194.8
Workers’ compensation loss reserves	17.3	17.4
Operating lease liabilities	26.3	0
Income taxes payable	15.7	3.4
Other current liabilities	38.4	49.5
Total current liabilities	313.7	308.2
Long-term debt	1,107.7	1,100.4
Operating lease liabilities	70.6	0
Deferred income tax liabilities	79.7	79.8
Other long-term liabilities	15.6	17.3
Total liabilities	1,587.3	1,505.7
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred Stock, Value, $0.01 par value	0	0
Common stock, $0.01 par value	0.5	0.5
Paid-in capital	613.2	601.8
Retained earnings	621	586.1
Accumulated other comprehensive loss	(7.4)	(6.3)
Total stockholders’ equity	1,227.3	1,182.1
Total liabilities and stockholders’ equity	$ 2,814.6	$ 2,687.8

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares shares in Millions, $ / shares in Millions	Mar. 31, 2019	Dec. 31, 2018
Stockholders’ equity:
Preferred Stock, par value (in dollars per share)	$ 0	$ 0
Preferred Stock, shares authorized (in shares)	1	1
Preferred Stock, shares issued (in shares)	0	0
Preferred Stock, shares outstanding (in shares)	0	0
Common Stock, par value (in dollars per share)	$ 0	$ 0
Common Stock, shares authorized (in shares)	75	75
Common Stock, Shares	52.8	52.5
Common Stock: shares outstanding (in shares)	52.8	52.5

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues	$ 923.7	$ 685.2
Cost of services	659.8	467.5
Gross profit	263.9	217.7
Selling, general and administrative expenses	187.4	164.4
Amortization of intangible assets	13.8	7.6
Operating income	62.7	45.7
Interest expense	(14.5)	(6.6)
Income before income taxes	48.2	39.1
Provision for income taxes	13.3	9.9
Income from continuing operations	34.9	29.2
Loss from discontinued operations, net of income taxes	0	(0.1)
Net income	$ 34.9	$ 29.1
Earnings per share:
Basic	$ 0.66	$ 0.56
Diluted	$ 0.66	$ 0.55
Number of shares and share equivalents used to calculate earnings per share:
Basic	52.6	52.2
Diluted	53.2	52.8
Reconciliation of net income to comprehensive income:
Net income	$ 34.9	$ 29.1
Foreign currency translation adjustment	(1.1)	1.5
Comprehensive income	$ 33.8	$ 30.6

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDER'S EQUITY - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Shares Outstanding at Dec. 31, 2017		52.2
Total stockholders’ equity at Dec. 31, 2017	$ 991.4	$ 0.5	$ 566.1	$ 428.4	$ (3.6)
Vesting of restricted stock units, value	(1)		(1)
Employee stock purchase plan, shares		0.1
Employee stock purchase plan, value	4.3		4.3
Exercise of stock options, value	0.1		0.1
Stock-based compensation expense	4.9		4.9
Translation adjustments	1.5				1.5
Net income	29.1			29.1
Shares Outstanding at Mar. 31, 2018		52.3
Total stockholders’ equity at Mar. 31, 2018	1,030.3	$ 0.5	574.4	457.5	(2.1)
Shares Outstanding at Dec. 31, 2018		52.5
Total stockholders’ equity at Dec. 31, 2018	1,182.1	$ 0.5	601.8	586.1	(6.3)
Vesting of restricted stock units, shares		0.2
Vesting of restricted stock units, value	(5.5)		(5.5)
Employee stock purchase plan, shares		0.1
Employee stock purchase plan, value	6.9		6.9
Stock-based compensation expense	10		10
Translation adjustments	(1.1)				(1.1)
Net income	34.9			34.9
Shares Outstanding at Mar. 31, 2019		52.8
Total stockholders’ equity at Mar. 31, 2019	$ 1,227.3	$ 0.5	$ 613.2	$ 621	$ (7.4)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash Flows from Operating Activities:
Net income	$ 34.9	$ 29.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	23.5	14.4
Stock-based compensation	9.5	4.9
Allowance for doubtful accounts	0.6	0.5
Workers’ compensation provision	0.6	0.8
Other	1.5	1.2
Changes in operating assets and liabilities:
Accounts receivable	4.6	(13.5)
Prepaid expenses and income taxes	(6.9)	8.2
Accounts payable	(17.3)	5.8
Accrued payroll and contract professional pay	(7.8)	6.5
Income taxes payable	12.3	(0.4)
Workers’ compensation loss reserves	(0.9)	(0.7)
Operating lease right of use assets	6.8	0
Operating lease liabilities	6.8	0
Other	(10.6)	(2.1)
Net Cash Provided by Operating Activities	44	54.7
Cash Flows from Investing Activities:
Cash paid for property and equipment	(7.5)	(6.2)
Cash paid for acquisitions, net of cash acquired	(48.8)	0
Other	(0.7)	0
Net cash used in investing activities	(57)	(6.2)
Cash Flows from Financing Activities:
Proceeds from long-term debt	44	0
Principal payments of long-term debt	(38)	(10)
Proceeds from option exercises and employee stock purchase plan	6.9	4.4
Payment of employment taxes related to release of restricted stock awards	(5.5)	(2.1)
Net Cash provided by (used in) Financing Activities	7.4	(7.7)
Effect of exchange rate changes on cash and cash equivalents	(0.6)	0.4
Net Increase (Decrease) in Cash and Cash Equivalents	(6.2)	41.2
Cash and Cash Equivalents at Beginning of Year	41.8	36.7
Cash and Cash Equivalents at End of Period	35.6	77.9
Supplemental Disclosure of Cash Flow Information:
Income taxes	1.6	1.1
Interest	12.8	5.3
Supplemental Disclosure of Non-Cash Transactions:
Unpaid portion of additions to property and equipment	$ 1.2	$ 2

Financial Statement Presentatio

Financial Statement Presentation (Notes)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Financial Statement Presentation	1. Financial Statement Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") and the rules of the Securities and Exchange Commission (the "SEC"). Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations. The December 31, 2018 condensed consolidated balance sheet was derived from audited financial statements. The financial statements include adjustments consisting of normal recurring items, which, in the opinion of management, are necessary for a fair presentation of the financial position of ASGN Incorporated and its subsidiaries ("ASGN" or the "Company") and its results of operations for the interim dates and periods set forth herein. The results for any of the interim periods are not necessarily indicative of the results to be expected for the full year or any other period. This Quarterly Report on Form 10-Q should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2018

Leases (Notes)

Leases (Notes)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Lessee, Leases	Effective January 1, 2019, the Company adopted Accounting Standards Update ("ASU") 2016-02 Leases (Accounting Standards Codification Topic "ASC" 842) , which requires lessees to recognize most operating leases on the balance sheet as a right of use ("ROU") asset and lease liability. The Company adopted this standard using the optional transition method measuring and recognizing the ROU asset and lease liability from operating leases on the condensed consolidated balance sheet without comparative period information or disclosures. The adoption of the standard did not have an effect on the Company’s results of operations, stockholders' equity or cash flows. The Company elected the package of practical expedients which specifies entities do not need to reassess expired or existing contracts as of the adoption date for the following items: (i) determination of whether a contract is or contains a lease, (ii) revising classification of leases and (iii) assessment of initial direct costs. For existing or expired contracts as of the adoption date, the determinations made for these items under the previous accounting standard (ASC 840) were retained at transition, as allowed by this package of practical expedients. The Company has operating leases for corporate offices, branch offices and data centers. At the transition date, the operating lease ROU asset and operating lease liability were $93.9 million and $99.4 million , respectively. The difference between the operating lease ROU asset and operating lease liability is due to pre-existing deferred rent and prepaid rent balances that were reclassified as a component of the ROU asset at the transition date. The Company's leases have remaining lease terms of one month to eight years . At the inception of a contract, the Company determines if the contract contains a lease. A contract contains a lease if it conveys the right to control the use of an identified asset for a period of time in exchange for consideration. Operating lease ROU assets and operating lease liabilities are recognized at the lease commencement date, based on the present value of the future minimum lease payments. Since most of the Company’s leases do not provide an implicit rate of return, the Company uses its incremental borrowing rate (“IBR”) in determining the present value of lease payments. In determining the IBR, the Company considers its credit rating and the current market interest rates. The IBR approximates the interest rate the Company would pay on collateralized debt with similar terms and payments as the lease agreements and in a similar economic environment where the leased assets are located. Leases with an initial term of 12 months or less ("short-term leases") are not recorded on the balance sheet. The Company does not have finance leases. Lease expense is recognized on a straight-line basis over the lease term and is primarily included in selling, general and administrative expenses. Some lease agreements offer renewal options which are assessed against relevant economic factors to determine whether it is reasonably certain that these renewal options will be exercised. As a result of this assessment, for most leases, renewal options were excluded from the minimum lease payments when calculating the operating lease ROU assets and operating lease liabilities, as the Company does not consider the exercise of such options to be reasonably certain.
Leases Disclosure	2. Leases Effective January 1, 2019, the Company adopted Accounting Standards Update ("ASU") 2016-02 Leases (Accounting Standards Codification Topic "ASC" 842) , which requires lessees to recognize most operating leases on the balance sheet as a right of use ("ROU") asset and lease liability. The Company adopted this standard using the optional transition method measuring and recognizing the ROU asset and lease liability from operating leases on the condensed consolidated balance sheet without comparative period information or disclosures. The adoption of the standard did not have an effect on the Company’s results of operations, stockholders' equity or cash flows. The Company elected the package of practical expedients which specifies entities do not need to reassess expired or existing contracts as of the adoption date for the following items: (i) determination of whether a contract is or contains a lease, (ii) revising classification of leases and (iii) assessment of initial direct costs. For existing or expired contracts as of the adoption date, the determinations made for these items under the previous accounting standard (ASC 840) were retained at transition, as allowed by this package of practical expedients. The Company has operating leases for corporate offices, branch offices and data centers. At the transition date, the operating lease ROU asset and operating lease liability were $93.9 million and $99.4 million , respectively. The difference between the operating lease ROU asset and operating lease liability is due to pre-existing deferred rent and prepaid rent balances that were reclassified as a component of the ROU asset at the transition date. The Company's leases have remaining lease terms of one month to eight years . At the inception of a contract, the Company determines if the contract contains a lease. A contract contains a lease if it conveys the right to control the use of an identified asset for a period of time in exchange for consideration. Operating lease ROU assets and operating lease liabilities are recognized at the lease commencement date, based on the present value of the future minimum lease payments. Since most of the Company’s leases do not provide an implicit rate of return, the Company uses its incremental borrowing rate (“IBR”) in determining the present value of lease payments. In determining the IBR, the Company considers its credit rating and the current market interest rates. The IBR approximates the interest rate the Company would pay on collateralized debt with similar terms and payments as the lease agreements and in a similar economic environment where the leased assets are located. Leases with an initial term of 12 months or less ("short-term leases") are not recorded on the balance sheet. The Company does not have finance leases. Lease expense is recognized on a straight-line basis over the lease term and is primarily included in selling, general and administrative expenses. Some lease agreements offer renewal options which are assessed against relevant economic factors to determine whether it is reasonably certain that these renewal options will be exercised. As a result of this assessment, for most leases, renewal options were excluded from the minimum lease payments when calculating the operating lease ROU assets and operating lease liabilities, as the Company does not consider the exercise of such options to be reasonably certain. The Company has lease agreements with lease and non-lease components, which are accounted for as a single lease component for all underlying asset classes. Some leases require variable payments for common area maintenance, property taxes, parking, insurance and other variable costs. The variable portion of lease payments is not included in operating lease ROU assets or operating lease liabilities. Variable lease costs are expensed when incurred. Leasehold improvements are amortized over the shorter of the useful life of the asset or the remaining term of the lease. Components of lease expense for the three months ended March 31, 2019 (in millions): Operating lease expense $ 7.9 Short-term lease expense 0.4 Variable lease expense 1.1 Total lease expense $ 9.4 Total rent expense for the three months ended March 31, 2018 was $6.9 million . The Company leases two properties owned indirectly by certain board members and an executive of the Company. Rent expense for these two properties was $0.3 million for the three months ended March 31, 2019 and 2018. Supplemental cash flow information related to leases for the three months ended March 31, 2019 (in millions): Cash paid for amounts included in the measurement of operating lease liabilities $ 7.9 Operating lease right of use assets obtained in exchange for new operating lease liabilities $ 4.4 Weighted-average remaining lease term of operating leases 4.3 years Weighted-average discount rate of operating leases 4.6 % Maturities of operating lease liabilities as of March 31, 2019 (in millions): Remainder of 2019 $ 23.6 2020 26.1 2021 21.8 2022 16.4 2023 11.1 Thereafter 8.6 Total future minimum lease payments 107.6 Less imputed interest (10.7 ) Total operating lease liabilities $ 96.9 As of March 31, 2019 , we have additional operating leases that have not yet commenced with total future lease payments of approximately $1.5 million . These operating leases will commence in 2019 with lease terms of approximately 5 years

Acquisitions (Notes)

Acquisitions (Notes)	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Acquisitions	3. Acquisitions Assets and liabilities of all acquired companies are recorded at their estimated fair values at the dates of acquisition. The fair value assigned to identifiable intangible assets was primarily determined using a discounted cash flow method (a non-recurring fair value measurement based on Level 3 inputs). Goodwill represents the acquired assembled workforce, potential new customers and future cash flows after the acquisition. DHA Acquisition On January 25, 2019 , the Company acquired all of the outstanding shares of DHA Group, Inc. ("DHA"), headquartered in Washington, D.C. , for $48.8 million , which included $2.8 million for excess working capital. DHA is a provider of IT services mainly to the FBI as well as other federal customers. The purchase accounting for the acquisition of DHA remains incomplete and any measurement period adjustments will be recognized prospectively over a period not to exceed 12 months from the date of acquisition. The results of operations for this acquisition have been combined with those of the Company from the acquisition date and are included within the ECS Segment (see Note 10. Segment Reporting ). ECS Acquisition On April 2, 2018 , the Company acquired all of the outstanding equity interests of ECS Federal, LLC ("ECS") for $775.0 million . ECS, which is headquartered in Fairfax, Virginia , is a leading provider of government IT services and solutions. The ECS acquisition allows the Company to compete in the Federal IT and professional services sector. The purchase accounting for this acquisition was finalized as of December 31, 2018. Goodwill related to this acquisition totaled $528.2 million , of which $514.2 million is deductible for income tax purposes. Identifiable intangible assets related to this acquisition totaled $195.0 million . The weighted-average amortization period for identifiable intangible assets, excluding trademark, is 11 years . The results of operations for this acquisition have been combined with those of the Company from the acquisition date and are included within the ECS Segment. The summary below (in millions, except for per share data) presents pro forma unaudited condensed consolidated results of operations for the three months ended March 31, 2018 as if the acquisition of ECS by the Company and the acquisition of a business by ECS in April 2017, both occurred on January 1, 2017. The pro forma unaudited condensed consolidated results give effect to, among other things: (i) amortization of intangible assets, (ii) stock-based compensation expense and the related dilution for restricted stock units granted to ECS employees, (iii) interest expense on acquisition-related debt and (iv) the exclusion of nonrecurring expenses incurred by ECS prior to its acquisition by the Company for ECS’ acquisition-related activities and costs incurred in the sale of ECS to the Company. The pro forma results do not include pre-acquisition results of DHA due to its size. The pro forma results are not necessarily indicative of the operating results that would have occurred had the acquisitions been consummated as of the date indicated, nor are they necessarily indicative of future operating results. Revenues $ 834.2 Income from continuing operations $ 34.6 Net income $ 34.5 Earnings per share: Basic $ 0.66 Diluted $ 0.65 Number of shares and share equivalents used to calculate earnings per share: Basic 52.2 Diluted 52.9

Goodwill and Identifiable Asset

Goodwill and Identifiable Assets (Notes)	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Identifiable Intangible Assets	4. Goodwill and Identifiable Intangible Assets The changes in the carrying amount of goodwill for the three months ended March 31, 2019 and the year ended December 31, 2018 were as follows (in millions): Apex Segment Oxford Segment ECS Segment Total Balance as of December 31, 2017 $ 662.1 $ 232.0 $ — $ 894.1 ECS acquisition — — 528.2 528.2 Translation adjustment — (1.2 ) — (1.2 ) Balance as of December 31, 2018 662.1 230.8 528.2 1,421.1 DHA acquisition — — 24.8 24.8 Translation adjustment — (0.4 ) — (0.4 ) Balance as of March 31, 2019 $ 662.1 $ 230.4 $ 553.0 $ 1,445.5 Acquired intangible assets consisted of the following (in millions): March 31, 2019 December 31, 2018 Estimated Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Subject to amortization: Customer and contractual relationships 2 - 12.75 years $ 362.4 $ 153.8 $ 208.6 $ 346.9 $ 145.4 $ 201.5 Contractor relationships 2 - 5 years 71.1 69.0 2.1 71.1 67.1 4.0 Backlog 1 - 2.75 years 25.0 19.2 5.8 23.1 17.7 5.4 Non-compete agreements 2 - 7 years 23.6 10.9 12.7 22.1 9.9 12.2 In-use software 6 years 18.9 16.8 2.1 18.9 16.0 2.9 Favorable contracts 5 years — — — 1.4 0.9 0.5 501.0 269.7 231.3 483.5 257.0 226.5 Not subject to amortization: Trademarks 262.1 — 262.1 262.2 — 262.2 Total $ 763.1 $ 269.7 $ 493.4 $ 745.7 $ 257.0 $ 488.7 Estimated future amortization expense is as follows (in millions): Remainder of 2019 $ 36.8 2020 38.1 2021 32.6 2022 24.9 2023 21.7 Thereafter 77.2 $ 231.3

Long-Term Debt (Notes)

Long-Term Debt (Notes)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Long-Term Debt	5. Long-Term Debt Long-term debt consisted of the following (in millions): March 31, December 31, $200 million revolving credit facility, due March 31, 2023 $ 6.0 $ — Term B loan facility, due June 5, 2022 337.0 337.0 Term B loan facility, due April 2, 2025 787.0 787.0 1,130.0 1,124.0 Unamortized deferred loan costs (22.3 ) (23.6 ) $ 1,107.7 $ 1,100.4 Borrowings under the term B loans bear interest at LIBOR, plus 2.00 percent . Borrowings under the revolving credit facility bear interest at LIBOR plus 1.25 to 2.25 percent , or the bank’s base rate plus 0.25 to 1.25 percent , depending on leverage levels. A commitment fee of 0.20 to 0.35 percent is payable on the undrawn portion of the revolving credit facility. At March 31, 2019 , the weighted average interest rate was 4.5 percent . For the term B loan that matures on June 5, 2022, there are no required minimum payments until its maturity date. For the term B loan that matures on April 2, 2025, the Company is required to make minimum quarterly payments of $2.1 million ; however, as a result of principal payments made through March 31, 2019 , the first required minimum quarterly payment of $2.1 million is not due until September 30, 2022 . The Company is also required to make mandatory prepayments on its term loans from excess cash flow and with the proceeds of asset sales, debt issuances and specified other events, subject to certain exceptions. The credit facility is secured by substantially all of our assets and has various restrictive covenants, including the maximum ratio of consolidated secured debt to consolidated earnings before interest, taxes, depreciation and amortization ("EBITDA"). The maximum permitted ratio of consolidated secured debt to consolidated EBITDA was 4.75 to 1.00 as of March 31, 2019 , and steps down at regular intervals to 3.75 to 1.00 as of September 30, 2021 and thereafter. The credit facility also contains certain customary limitations including, among other terms and conditions, the Company's ability to incur additional indebtedness, engage in mergers and acquisitions and declare dividends. At March 31, 2019 , the Company was in compliance with its debt covenants; its ratio of consolidated secured debt to consolidated EBITDA was 2.65 to 1.00, and it had $190.1 million

Commitments and Contingencies (

Commitments and Contingencies (Notes)	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies The Company carries retention policies for its workers’ compensation liability exposures. The workers' compensation loss reserves are based upon an actuarial study conducted by a third-party specialist. Changes in estimates and differences between estimates and the actual payments for claims are recognized in the period that the estimates change or the payments are made. The workers' compensation loss reserves were approximately $2.1 million and $2.4 million , at March 31, 2019 and December 31, 2018 , net of anticipated insurance and indemnification recoveries of $15.2 million and $15.0 million , at March 31, 2019 and December 31, 2018 , respectively. We have undrawn stand-by letters of credit outstanding to secure obligations for workers’ compensation claims with various insurance carriers. These stand-by letters of credit at March 31, 2019 and December 31, 2018 were $3.9 million and $4.4 million , respectively. The Company’s deferred compensation plan liability was $10.2 million and $6.2 million at March 31, 2019 and December 31, 2018 and was included in other long-term liabilities. The Company established a rabbi trust to fund the deferred compensation plan (see Note 11. Fair Value Measurements ). Legal Proceedings

Revenues (Notes)

Revenues (Notes)	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenues	7. Revenues Revenues are recognized as control of the promised service is transferred to customers, in an amount that reflects the consideration expected in exchange for the services. The Company’s contracts have termination for convenience provisions and do not have substantive termination penalties; therefore, the contract duration for accounting purposes may be less than the stated terms. For accounting purposes, the Company's contracts with customers are considered to be of a short-term nature (one year or less). The Company does not disclose the value of remaining performance obligations for short-term contracts. The Company has contract liabilities for payments received in advance of providing services under certain contracts. Contract liabilities for advance payments were $3.8 million and $9.8 million at March 31, 2019 and December 31, 2018 , respectively. Contract liabilities are included in other current liabilities on the condensed consolidated balance sheets. During the three months ended March 31, 2019 , the Company recognized revenues of $8.8 million relating to amounts that were included in contract liabilities as of December 31, 2018 . The allowance for doubtful accounts was $4.6 million at March 31, 2019 and $4.8 million at December 31, 2018

Income Taxes (Notes)

Income Taxes (Notes)	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes

Earnings Per Share (Notes)

Earnings Per Share (Notes)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings per share	9. Earnings per Share The following is a reconciliation of the shares used to compute basic and diluted earnings per share (in millions): Three Months Ended March 31, 2019 2018 Weighted average number of common shares outstanding used to compute basic earnings per share 52.6 52.2 Dilutive effect of stock-based awards 0.6 0.6 Number of shares used to compute diluted earnings per share 53.2 52.8 There were 0.3 million share equivalents outstanding during the three months ended March 31, 2019 that were anti-dilutive when applying the treasury stock method and thus were excluded from the number of shares used to compute diluted earnings per share. The number of anti-dilutive share equivalents outstanding during the three months ended March 31, 2018

Segment Reporting (Notes)

Segment Reporting (Notes)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Segment Reporting	10. Segment Reporting ASGN provides IT and professional staffing services in the technology, digital, creative, engineering and life sciences fields across commercial and government sectors. ASGN operates through its Apex, Oxford and ECS segments. The Apex Segment provides technology, scientific, engineering, digital and creative resources and services to Fortune 1000 and mid-market clients across the United States and Canada. The businesses in this segment include Apex Systems and Creative Circle. The Oxford Segment provides hard-to-find technical, digital, engineering and life sciences resources in select skill and geographic markets, along with consulting services. The businesses in this segment include Oxford Global Resources, CyberCoders and Life Sciences Europe. The ECS Segment provides advanced solutions in cloud, cybersecurity, artificial intelligence, machine learning, application and IT modernization and science and engineering to customers across the U.S. public sector, defense, intelligence and commercial industries. The Company’s management evaluates the performance of each segment primarily based on revenues, gross profit and operating income. The information in the following tables is derived directly from the segments’ internal financial reporting used for corporate management purposes. The following tables present revenues, gross profit, operating income and amortization by reportable segment (in millions): Three Months Ended March 31, 2019 2018 Apex: Revenues $ 606.1 $ 538.5 Gross profit 175.4 158.6 Operating income 61.0 56.3 Amortization 6.0 6.5 Oxford: Revenues $ 149.6 $ 146.7 Gross profit 58.9 59.1 Operating income 11.7 9.8 Amortization 1.0 1.1 ECS: Revenues $ 168.0 $ — Gross profit 29.6 — Operating income 6.9 — Amortization 6.8 — Corporate: Operating loss (1) $ (16.9 ) $ (20.4 ) Consolidated: Revenues $ 923.7 $ 685.2 Gross profit 263.9 217.7 Operating income 62.7 45.7 Amortization 13.8 7.6 _____________ (1) Corporate expenses primarily consist of consolidated stock-based compensation expense, compensation for corporate employees, acquisition, integration and strategic planning expenses, public company expenses and depreciation expense for corporate assets. The following table presents our revenues disaggregated by type (in millions): Three Months Ended March 31, 2019 2018 Apex: Assignment $ 592.2 $ 524.9 Permanent placement 13.9 13.6 $ 606.1 $ 538.5 Oxford: Assignment $ 129.4 $ 125.4 Permanent placement 20.2 21.3 $ 149.6 $ 146.7 ECS: Firm-fixed-price $ 43.3 $ — Time and materials 61.4 — Cost-plus-fixed-fee 63.3 — $ 168.0 $ — Consolidated $ 923.7 $ 685.2 The Company operates internationally, with operations mainly in the United States. The following table presents revenues by geographic location (in millions): Three Months Ended March 31, 2019 % 2018 % Revenues: Domestic $ 881.1 95.4 % $ 647.3 94.5 % Foreign 42.6 4.6 % 37.9 5.5 % $ 923.7 100.0 % $ 685.2 100.0 % The following table presents the ECS segment revenues by customer type (in millions): Three Months Ended March 31, 2019 Department of Defense and Intelligence Agencies $ 96.0 Federal Civilian 60.2 Commercial and Other 11.8 $ 168.0

Fair Value Measurements (Notes)

Fair Value Measurements (Notes)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	11. Fair Value Measurements The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and accrued payroll and contractor professional pay approximate their fair value based on their short-term nature. The carrying value of the revolving credit facility approximates its fair value. The fair value of the term B loans was $1.1 billion as of March 31, 2019 , excluding the $22.3 million of unamortized deferred loan costs (see Note 5. Long-Term Debt ) and was determined using Level 1 inputs (quoted prices in active markets for identical assets and liabilities) from the fair value hierarchy. The Company had investments, primarily mutual funds, of $10.1 million and $6.2 million at March 31, 2019 and December 31, 2018 , held in a rabbi trust restricted to fund the Company's deferred compensation plan. The fair value of these investments was determined using Level 1 inputs from the fair value hierarchy. These assets are included in other non-current assets. Certain assets and liabilities, such as goodwill and trademarks, are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (e.g., when there is evidence of impairment). For the three months ended March 31, 2019 and 2018

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Lease, Cost	Components of lease expense for the three months ended March 31, 2019 (in millions): Operating lease expense $ 7.9 Short-term lease expense 0.4 Variable lease expense 1.1 Total lease expense $ 9.4
Cash Flow, Supplemental Disclosures	Supplemental cash flow information related to leases for the three months ended March 31, 2019 (in millions): Cash paid for amounts included in the measurement of operating lease liabilities $ 7.9 Operating lease right of use assets obtained in exchange for new operating lease liabilities $ 4.4 Weighted-average remaining lease term of operating leases 4.3 years Weighted-average discount rate of operating leases 4.6 %
Lessee, Operating Lease, Liability, Maturity	Maturities of operating lease liabilities as of March 31, 2019 (in millions): Remainder of 2019 $ 23.6 2020 26.1 2021 21.8 2022 16.4 2023 11.1 Thereafter 8.6 Total future minimum lease payments 107.6 Less imputed interest (10.7 ) Total operating lease liabilities $ 96.9

Acquisitions (Tables)

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Business Acquisition, Pro Forma Information	The summary below (in millions, except for per share data) presents pro forma unaudited condensed consolidated results of operations for the three months ended March 31, 2018 as if the acquisition of ECS by the Company and the acquisition of a business by ECS in April 2017, both occurred on January 1, 2017. The pro forma unaudited condensed consolidated results give effect to, among other things: (i) amortization of intangible assets, (ii) stock-based compensation expense and the related dilution for restricted stock units granted to ECS employees, (iii) interest expense on acquisition-related debt and (iv) the exclusion of nonrecurring expenses incurred by ECS prior to its acquisition by the Company for ECS’ acquisition-related activities and costs incurred in the sale of ECS to the Company. The pro forma results do not include pre-acquisition results of DHA due to its size. The pro forma results are not necessarily indicative of the operating results that would have occurred had the acquisitions been consummated as of the date indicated, nor are they necessarily indicative of future operating results. Revenues $ 834.2 Income from continuing operations $ 34.6 Net income $ 34.5 Earnings per share: Basic $ 0.66 Diluted $ 0.65 Number of shares and share equivalents used to calculate earnings per share: Basic 52.2 Diluted 52.9

Goodwill and Identifiable Ass_2

Goodwill and Identifiable Assets (Tables)	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The changes in the carrying amount of goodwill for the three months ended March 31, 2019 and the year ended December 31, 2018 were as follows (in millions): Apex Segment Oxford Segment ECS Segment Total Balance as of December 31, 2017 $ 662.1 $ 232.0 $ — $ 894.1 ECS acquisition — — 528.2 528.2 Translation adjustment — (1.2 ) — (1.2 ) Balance as of December 31, 2018 662.1 230.8 528.2 1,421.1 DHA acquisition — — 24.8 24.8 Translation adjustment — (0.4 ) — (0.4 ) Balance as of March 31, 2019 $ 662.1 $ 230.4 $ 553.0 $ 1,445.5
Schedule of Acquired Intangible Assets	Acquired intangible assets consisted of the following (in millions): March 31, 2019 December 31, 2018 Estimated Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Subject to amortization: Customer and contractual relationships 2 - 12.75 years $ 362.4 $ 153.8 $ 208.6 $ 346.9 $ 145.4 $ 201.5 Contractor relationships 2 - 5 years 71.1 69.0 2.1 71.1 67.1 4.0 Backlog 1 - 2.75 years 25.0 19.2 5.8 23.1 17.7 5.4 Non-compete agreements 2 - 7 years 23.6 10.9 12.7 22.1 9.9 12.2 In-use software 6 years 18.9 16.8 2.1 18.9 16.0 2.9 Favorable contracts 5 years — — — 1.4 0.9 0.5 501.0 269.7 231.3 483.5 257.0 226.5 Not subject to amortization: Trademarks 262.1 — 262.1 262.2 — 262.2 Total $ 763.1 $ 269.7 $ 493.4 $ 745.7 $ 257.0 $ 488.7
Schedule of Estimated Future Amortization Expense	Estimated future amortization expense is as follows (in millions): Remainder of 2019 $ 36.8 2020 38.1 2021 32.6 2022 24.9 2023 21.7 Thereafter 77.2 $ 231.3

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt consisted of the following (in millions): March 31, December 31, $200 million revolving credit facility, due March 31, 2023 $ 6.0 $ — Term B loan facility, due June 5, 2022 337.0 337.0 Term B loan facility, due April 2, 2025 787.0 787.0 1,130.0 1,124.0 Unamortized deferred loan costs (22.3 ) (23.6 ) $ 1,107.7 $ 1,100.4

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Reconciliation of Shares Used to Compute Basic and Diluted Earnings per Share	The following is a reconciliation of the shares used to compute basic and diluted earnings per share (in millions): Three Months Ended March 31, 2019 2018 Weighted average number of common shares outstanding used to compute basic earnings per share 52.6 52.2 Dilutive effect of stock-based awards 0.6 0.6 Number of shares used to compute diluted earnings per share 53.2 52.8

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting Information [Line Items]
Revenue from External Customers by Products and Services [Table Text Block]	The following table presents the ECS segment revenues by customer type (in millions): Three Months Ended March 31, 2019 Department of Defense and Intelligence Agencies $ 96.0 Federal Civilian 60.2 Commercial and Other 11.8 $ 168.0
Schedule of Segment Reporting Information, by Segment	The following tables present revenues, gross profit, operating income and amortization by reportable segment (in millions): Three Months Ended March 31, 2019 2018 Apex: Revenues $ 606.1 $ 538.5 Gross profit 175.4 158.6 Operating income 61.0 56.3 Amortization 6.0 6.5 Oxford: Revenues $ 149.6 $ 146.7 Gross profit 58.9 59.1 Operating income 11.7 9.8 Amortization 1.0 1.1 ECS: Revenues $ 168.0 $ — Gross profit 29.6 — Operating income 6.9 — Amortization 6.8 — Corporate: Operating loss (1) $ (16.9 ) $ (20.4 ) Consolidated: Revenues $ 923.7 $ 685.2 Gross profit 263.9 217.7 Operating income 62.7 45.7 Amortization 13.8 7.6 _____________ (1)
Disaggregation of Revenue	The following table presents our revenues disaggregated by type (in millions): Three Months Ended March 31, 2019 2018 Apex: Assignment $ 592.2 $ 524.9 Permanent placement 13.9 13.6 $ 606.1 $ 538.5 Oxford: Assignment $ 129.4 $ 125.4 Permanent placement 20.2 21.3 $ 149.6 $ 146.7 ECS: Firm-fixed-price $ 43.3 $ — Time and materials 61.4 — Cost-plus-fixed-fee 63.3 — $ 168.0 $ — Consolidated $ 923.7 $ 685.2
Schedule of Revenue by Geographical Areas	The Company operates internationally, with operations mainly in the United States. The following table presents revenues by geographic location (in millions): Three Months Ended March 31, 2019 % 2018 % Revenues: Domestic $ 881.1 95.4 % $ 647.3 94.5 % Foreign 42.6 4.6 % 37.9 5.5 % $ 923.7 100.0 % $ 685.2 100.0 %

Leases (Details)

Leases (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)property	Mar. 31, 2018USD ($)	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)
Other Commitments [Line Items]
Operating lease right of use assets	$ 91.4		$ 93.9	$ 0
Operating lease liability	96.9		$ 99.4
Operating Leases, Rent Expense	$ 6.9
Number of Leased Properties Owned by Related Parties | property	2
Costs and Expenses, Related Party	$ 0.3	$ 0.3
Lessee, Operating Lease, Leases Not Yet Commenced, Value	$ 1.5
Lessee, Operating Lease, Leases Not yet Commenced, Term of Contract	5 years

Lease, Cost (Details)

Lease, Cost (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Lease, Cost [Abstract]
Operating Lease, Expense	$ 7.9
Short-term Lease, Expense	0.4
Variable Lease, Expense	1.1
Total lease expense	$ 9.4

Leases Supplemental Information

Leases Supplemental Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)Rate
Operating Lease Liabilities, Payments Due [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 7.9
Operating lease right of use assets obtained in exchange for new operating leases	$ 4.4
Operating Lease, Weighted Average Remaining Lease Term	4 years 3 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent | Rate	4.60%

Leases Operating Lease Liabilit

Leases Operating Lease Liabilities Payments Due (Details) - USD ($) $ in Millions	Mar. 31, 2019	Jan. 01, 2019
Operating Lease Liabilities, Payments Due [Abstract]
Remainder of 2019	$ 23.6
2020	26.1
2021	21.8
2022	16.4
2023	11.1
Thereafter	8.6
Total future minimum lease payments	107.6
Less Imputed interest	(10.7)
Operating lease liability	$ 96.9	$ 99.4

Leases Lease Terms (Details)

Leases Lease Terms (Details)	Mar. 31, 2019
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	1 month
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	8 years

Acquisitions Business Combinati

Acquisitions Business Combinations Additional Information (Details) - USD ($) $ in Millions	Jan. 25, 2019	Apr. 02, 2018	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Business Acquisition [Line Items]
Cash paid for acquisitions, net of cash acquired			$ 48.8	$ 0
Goodwill			$ 1,445.5		$ 1,421.1
DHA
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Jan. 25, 2019
Business Acquisition, Name of Acquired Entity	DHA Group, Inc.
Business Acquisition, Description of Acquired Entity	headquartered in Washington, D.C.
Working capital excess of target working capital	$ 2.8
ECS
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition		Apr. 2, 2018
Business Acquisition, Name of Acquired Entity		ECS Federal, LLC
Business Acquisition, Description of Acquired Entity		headquartered in Fairfax, Virginia
Payments to Acquire Businesses, Gross		$ 775
Business Combination, Reason for Business Combination		The ECS acquisition allows the Company to compete in the Federal IT and professional services sector.
Goodwill		$ 528.2
Business Acquisition, Goodwill, Expected Tax Deductible Amount		514.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets		$ 195
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		11 years

Acquisitions Pro Forma (Details

Acquisitions Pro Forma (Details) - ECS $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Business Acquisition, Pro Forma Revenue	$ 834.2
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax	34.6
Business Acquisition, Pro Forma Net Income (Loss)	$ 34.5
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax, Per Share, Basic | $ / shares	$ 0.66
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax, Per Share, Diluted | $ / shares	$ 0.65
Weighted Average Basic Shares Outstanding, Pro Forma | shares	52.2
Pro Forma Weighted Average Shares Outstanding, Diluted | shares	52.9

Goodwill and Identifiable Ass_3

Goodwill and Identifiable Assets (Goodwill) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Apr. 02, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Gross goodwill	$ 1,445.5		$ 1,421.1		$ 894.1
Goodwill, Acquired During Period	24.8	$ 528.2
Translation adjustment	(0.4)	(1.2)
Goodwill	1,445.5		1,421.1
Apex
Goodwill [Roll Forward]
Gross goodwill	662.1		662.1		662.1
Oxford
Goodwill [Roll Forward]
Gross goodwill	230.4		230.8		$ 232
Translation adjustment	(0.4)	(1.2)
ECS
Goodwill [Roll Forward]
Gross goodwill	553		$ 528.2
Goodwill				$ 528.2
DHA | DHA
Goodwill [Roll Forward]
Goodwill, Acquired During Period	$ 24.8
ECS | ECS
Goodwill [Roll Forward]
Goodwill, Acquired During Period		$ 528.2

Goodwill and Identifiable Ass_4

Goodwill and Identifiable Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Millions	Apr. 02, 2018	Mar. 31, 2019	Dec. 31, 2018
Intangible assets subject to amortization:
Gross Carrying Amount		$ 501	$ 483.5
Accumulated Amortization		269.7	257
Net Carrying Amount		231.3	226.5
Intangible assets not subject to amortization:
Trademarks, Carrying Amount		262.1	262.2
Intangible Assets, Gross (Excluding Goodwill)		763.1	745.7
Intangible Assets, Net (Excluding Goodwill)		493.4	488.7
Customer and Contractual Relationships
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	12 years 9 months
Intangible assets subject to amortization:
Gross Carrying Amount		362.4	346.9
Accumulated Amortization		153.8	145.4
Net Carrying Amount		$ 208.6	201.5
Customer and Contractual Relationships | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		2 months
Customer and Contractual Relationships | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		12 years 9 months
Contractor Relations
Intangible assets subject to amortization:
Gross Carrying Amount		$ 71.1	71.1
Accumulated Amortization		69	67.1
Net Carrying Amount		$ 2.1	4
Contractor Relations | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		2 years
Contractor Relations | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		5 years
Backlog
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	2 years 9 months
Intangible assets subject to amortization:
Gross Carrying Amount		$ 25	23.1
Accumulated Amortization		19.2	17.7
Net Carrying Amount		$ 5.8	5.4
Backlog | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		1 year
Backlog | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		2 years 9 months
Noncompete Agreements
Intangible assets subject to amortization:
Gross Carrying Amount		$ 23.6	22.1
Accumulated Amortization		10.9	9.9
Net Carrying Amount		$ 12.7	12.2
Noncompete Agreements | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	4 years	2 years
Noncompete Agreements | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years	7 years
In-use software
Intangible assets subject to amortization:
Gross Carrying Amount		$ 18.9	18.9
Accumulated Amortization		16.8	16
Net Carrying Amount		$ 2.1	2.9
In-use software | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		6 years
Favorable Contracts
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years
Intangible assets subject to amortization:
Gross Carrying Amount		$ 0	1.4
Accumulated Amortization		0	0.9
Net Carrying Amount		$ 0	$ 0.5
Favorable Contracts | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life		5 years

Goodwill and Identifiable Ass_5

Goodwill and Identifiable Assets (Future Amortization Expense) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2019	$ 36.8
2020	38.1
2021	32.6
2022	24.9
2023	21.7
Thereafter	77.2
Net Carrying Amount	$ 231.3	$ 226.5

Long-Term Debt Schedule (Detail

Long-Term Debt Schedule (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Secured Debt	$ 1,130	$ 1,124
Unamortized deferred loan costs	(22.3)	(23.6)
Long-term Debt	1,107.7	1,100.4
$200 Million Revolving Credit Facility, Due March 2023 [Member]
Debt Instrument [Line Items]
Secured Debt	6	0
$825 Million Term B Loan Facility, due June 2022 [Member]
Debt Instrument [Line Items]
Secured Debt	337	337
$822 Million Term B Loan Facility, due April 2025 [Member]
Debt Instrument [Line Items]
Secured Debt	$ 787	$ 787

Long-term Debt (Details)

Long-term Debt (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)Rate	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Unamortized deferred loan costs | $	$ 22.3	$ 23.6
Long-term Debt | $	1,107.7	$ 1,100.4
Contractual Quarterly Payments | $	$ 2.1
Leverage Ratio	2.65
Maximum [Member]
Debt Instrument [Line Items]
Leverage Ratio in Latest Year of Debt Term	3.75%
Leverage Ratio	4.75%
Notes Payable to Banks [Member] | Minimum [Member] | $200 Million Revolving Credit Facility, Due March 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.25%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.20%
Notes Payable to Banks [Member] | Minimum [Member] | Eurodollar [Member] | $200 Million Revolving Credit Facility, Due March 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.25%
Notes Payable to Banks [Member] | Maximum [Member] | $200 Million Revolving Credit Facility, Due March 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.25%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.35%
Notes Payable to Banks [Member] | Maximum [Member] | $825 Million Term B Loan Facility, due June 2022 [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Interest Rate During Period	4.50%
Notes Payable to Banks [Member] | Maximum [Member] | Eurodollar [Member] | $200 Million Revolving Credit Facility, Due March 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.25%
Notes Payable to Banks [Member] | Maximum [Member] | Eurodollar [Member] | $825 Million Term B Loan Facility, due June 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.00%
$200 Million Revolving Credit Facility, Due March 2023 [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity | $	$ 190.1

Commitments and Contingencies_2

Commitments and Contingencies (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Other Commitments [Line Items]
Self Insurance Reserve	$ 2.1	$ 2.4
Estimated Insurance Recoveries	15.2	15
Letters of Credit Outstanding, Amount	3.9	4.4
Deferred Compensation Liability, Noncurrent	$ 10.2	$ 6.2

Revenues (Details)

Revenues (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Deferred Revenue	$ 3.8	$ 9.8
Contract with Customer, Liability, Revenue Recognized	8.8
Allowance for Doubtful Accounts Receivable, Current	$ 4.6	$ 4.8

Earnings Per Share (Details)

Earnings Per Share (Details) - shares shares in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.3
Weighted Average Number of Shares Outstanding Reconciliation
Weighted average number of common shares outstanding used to compute basic earnings per share	52.6	52.2
Dilutive effect of stock-based awards	0.6	0.6
Number of shares used to compute diluted earnings per share	53.2	52.8

Segment Reporting (Segment Repo

Segment Reporting (Segment Reporting Information) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Revenues:
Revenues		$ 923.7	$ 685.2
Gross Profit:
Total Gross Profit		263.9	217.7
Operating Income (Loss):
Total Operating Income		62.7	45.7
Amortization of Intangible Assets		13.8	7.6
Apex
Revenues:
Revenues		606.1	538.5
Gross Profit:
Total Gross Profit		175.4	158.6
Operating Income (Loss):
Total Operating Income		61	56.3
Amortization of Intangible Assets		6	6.5
Oxford
Revenues:
Revenues		149.6	146.7
Gross Profit:
Total Gross Profit		58.9	59.1
Operating Income (Loss):
Total Operating Income		11.7	9.8
Amortization of Intangible Assets		1	1.1
ECS
Revenues:
Revenues		168	0
Gross Profit:
Total Gross Profit		29.6	0
Operating Income (Loss):
Total Operating Income		6.9	0
Amortization of Intangible Assets		6.8	0
Corporate
Operating Income (Loss):
Total Operating Income	[1]	(16.9)	(20.4)
Assignment | Apex
Revenues:
Revenues		592.2	524.9
Assignment | Oxford
Revenues:
Revenues		129.4	125.4
Permanent Placement | Apex
Revenues:
Revenues		13.9	13.6
Permanent Placement | Oxford
Revenues:
Revenues		20.2	21.3
Fixed-price Contract | ECS
Revenues:
Revenues		43.3	0
Time-and-materials Contract | ECS
Revenues:
Revenues		61.4	0
Cost-plus-fixed-fee Contract | ECS
Revenues:
Revenues		$ 63.3	$ 0
[1]	Corporate expenses primarily consist of consolidated stock-based compensation expense, compensation for corporate employees, acquisition, integration and strategic planning expenses, public company expenses and depreciation expense for corporate assets.

Segment Reporting (Revenue by G

Segment Reporting (Revenue by Geographical Areas) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues from External Customers [Line Items]
Revenues	$ 923.7	$ 685.2
Revenue as Percentage of Consolidated Revenue	100.00%	100.00%
Domestic
Revenues from External Customers [Line Items]
Revenues	$ 881.1	$ 647.3
Revenue as Percentage of Consolidated Revenue	95.40%	94.50%
Foreign
Revenues from External Customers [Line Items]
Revenues	$ 42.6	$ 37.9
Revenue as Percentage of Consolidated Revenue	4.60%	5.50%

Segment Reporting Revenue by Cu

Segment Reporting Revenue by Customer Type (details) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue from External Customer [Line Items]
Revenues	$ 923.7	$ 685.2
Department of Defense and Intelligence Agencies
Revenue from External Customer [Line Items]
Revenues	96
Federal Civilian
Revenue from External Customer [Line Items]
Revenues	60.2
Commercial and Other
Revenue from External Customer [Line Items]
Revenues	11.8
ECS
Revenue from External Customer [Line Items]
Revenues	$ 168	$ 0

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Inputs, Liabilities, Quantitative Information) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Fair Value Inputs, Liabilities, Quantitative Information
Unamortized deferred loan costs	$ 22.3	$ 23.6
Level 1 Inputs
Fair Value Inputs, Liabilities, Quantitative Information
Long-term debt, fair value	1,100
Deferred Compensation Plan Assets	$ 10.1	$ 6.2