ASGN (ASGN) 10-Q 8 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares shares in Millions	6 Months Ended
	Jun. 30, 2019	Aug. 01, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	000-20540
Entity Registrant Name	ASGN Inc
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	95-4023433
Entity Address, Address Description	26745 Malibu Hills Road
Entity Address, City or Town	Calabasas
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	91301
City Area Code	818
Local Phone Number	878-7900
Title of 12(b) Security	Common Stock
Trading Symbol	ASGN
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		52.9
Entity Central Index Key	0000890564
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 40.1	$ 41.8
Accounts receivable, net	621.5	613.8
Prepaid expenses and income taxes	15.2	11.4
Workers' compensation receivable	14.7	15
Other current assets	5.6	4.3
Total current assets	697.1	686.3
Property and equipment, net	75.2	79.1
Operating lease right of use assets	87.7	0
Identifiable intangible assets, net	476.9	488.7
Goodwill	1,445.6	1,421.1
Other non-current assets	16.5	12.6
Total assets	2,799	2,687.8
Current liabilities:
Accounts payable	24.1	43.1
Accrued payroll and contract professional pay	196.5	194.8
Workers’ compensation loss reserves	16.8	17.4
Operating lease liabilities	25.8	0
Income taxes payable	13.5	3.4
Other current liabilities	49.8	49.5
Total current liabilities	326.5	308.2
Long-term debt	1,026	1,100.4
Operating lease liabilities	67.7	0
Deferred income tax liabilities	78.9	79.8
Other long-term liabilities	16.2	17.3
Total liabilities	1,515.3	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	625.5	601.8
Retained earnings	664.1	586.1
Accumulated other comprehensive loss	(6.4)	(6.3)
Total stockholders’ equity	1,283.7	1,182.1
Total liabilities and stockholders’ equity	$ 2,799	$ 2,687.8

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares shares in Millions, $ / shares in Millions	Jun. 30, 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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues	$ 972.3	$ 878.5	$ 1,896	$ 1,563.7
Cost of services	687.1	614.6	1,346.9	1,082.1
Gross profit	285.2	263.9	549.1	481.6
Selling, general and administrative expenses	198.8	179.7	386.2	344.1
Amortization of intangible assets	13.1	18.5	26.9	26.1
Operating income	73.3	65.7	136	111.4
Interest expense	(14)	(20.5)	(28.5)	(27.1)
Income before income taxes	59.3	45.2	107.5	84.3
Provision for income taxes	16.2	11.5	29.5	21.4
Income from continuing operations	43.1	33.7	78	62.9
Loss from discontinued operations, net of income taxes	0	(0.1)	0	(0.2)
Net income	$ 43.1	$ 33.6	$ 78	$ 62.7
Earnings per share:
Basic	$ 0.82	$ 0.64	$ 1.48	$ 1.20
Diluted	$ 0.81	$ 0.63	$ 1.46	$ 1.19
Number of shares and share equivalents used to calculate earnings per share:
Basic	52.8	52.3	52.7	52.2
Diluted	53.4	53	53.3	52.9
Reconciliation of net income to comprehensive income:
Net income	$ 43.1	$ 33.6	$ 78	$ 62.7
Foreign currency translation adjustment	1	(2.7)	(0.1)	(1.2)
Comprehensive income	$ 44.1	$ 30.9	$ 77.9	$ 61.5

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	(2.2)		(2.2)
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	13.6		13.6
Translation adjustments	(1.2)				(1.2)
Net income	62.7			62.7
Shares Outstanding at Jun. 30, 2018		52.3
Total stockholders’ equity at Jun. 30, 2018	1,068.7	$ 0.5	581.9	491.1	(4.8)
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)
Vesting of restricted stock units, value	(1.2)		(1.2)
Stock-based compensation expense	8.7		8.7
Translation adjustments	(2.7)				(2.7)
Net income	33.6			33.6
Shares Outstanding at Jun. 30, 2018		52.3
Total stockholders’ equity at Jun. 30, 2018	1,068.7	$ 0.5	581.9	491.1	(4.8)
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	(6.8)		(6.8)
Employee stock purchase plan, shares		0.1
Employee stock purchase plan, value	6.9		6.9
Stock-based compensation expense	23.6		23.6
Translation adjustments	(0.1)				(0.1)
Net income	78			78
Shares Outstanding at Jun. 30, 2019		52.8
Total stockholders’ equity at Jun. 30, 2019	1,283.7	$ 0.5	625.5	664.1	(6.4)
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)
Vesting of restricted stock units, value	(1.3)		(1.3)
Stock-based compensation expense	13.6		13.6
Translation adjustments	1				1
Net income	43.1			43.1
Shares Outstanding at Jun. 30, 2019		52.8
Total stockholders’ equity at Jun. 30, 2019	$ 1,283.7	$ 0.5	$ 625.5	$ 664.1	$ (6.4)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash Flows from Operating Activities:
Net income	$ 78	$ 62.7
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	46.6	43
Stock-based compensation	23.3	13.8
Allowance for doubtful accounts	1.7	1.3
Workers’ compensation provision	1.3	1.4
Other	5.5	8.4
Changes in operating assets and liabilities:
Accounts receivable	1	(32)
Prepaid expenses and income taxes	(5.3)	12
Accounts payable	(21)	(3.2)
Accrued payroll and contract professional pay	0.5	22.2
Income taxes payable	10	4.9
Workers’ compensation loss reserves	(1.6)	(1.5)
Operating lease right of use assets	13.9	0
Operating lease liabilities	(13.7)	0
Other	0.3	(1.5)
Net Cash Provided by Operating Activities	140.5	131.5
Cash Flows from Investing Activities:
Cash paid for property and equipment	(15.9)	(14.6)
Cash paid for acquisitions, net of cash acquired	(48.5)	(760.5)
Other	(0.9)	(0.1)
Net cash used in investing activities	(65.3)	(775.2)
Cash Flows from Financing Activities:
Proceeds from long-term debt	50	822
Principal payments of long-term debt	(127)	(143)
Payments of Debt Issuance Costs	0	22.5
Proceeds from option exercises and employee stock purchase plan	6.9	4.4
Payment of employment taxes related to release of restricted stock awards	(6.8)	(3.2)
Proceeds from (Payments for) Other Financing Activities	0	(5.3)
Net Cash provided by (used in) Financing Activities	(76.9)	652.4
Effect of exchange rate changes on cash and cash equivalents	0	(0.7)
Net Increase (Decrease) in Cash and Cash Equivalents	(1.7)	8
Cash and Cash Equivalents at Beginning of Year	41.8	36.7
Cash and Cash Equivalents at End of Period	40.1	44.7
Supplemental Disclosure of Cash Flow Information:
Income taxes	21	4.6
Interest	25.4	24.7
Supplemental Disclosure of Non-Cash Transactions:
Unpaid portion of additions to property and equipment	$ 1.1	$ 1.7

Financial Statement Presentatio

Financial Statement Presentation (Notes)	6 Months Ended
	Jun. 30, 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

Accounting Standard Update (Not

Accounting Standard Update (Notes)	6 Months Ended
	Jun. 30, 2019
Accounting Standard Update [Abstract]
New Accounting Pronouncements	2. Accounting Standards Update In July 2019, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2019-07, Codification Updates to SEC Sections , to incorporate the SEC Final Rule Release No. 33-10532 Disclosure Update and Simplification. This rule was issued in August 2018 and amends certain disclosure requirements that were redundant, duplicative, overlapping, outdated or superseded. This rule was adopted by the Company effective January 1, 2019 and the only significant change was the inclusion of the statement of changes in stockholders’ equity for interim periods.

Leases (Notes)

Leases (Notes)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases Disclosure	3. 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 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. Components of lease expense were as follows (in millions): Three Months Ended Six Months Ended June 30, 2019 June 30, 2019 Operating lease expense $ 8.0 $ 15.9 Short-term lease expense 0.4 0.8 Variable lease expense 1.2 2.3 Total lease expense $ 9.6 $ 19.0 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 and $0.6 million for the three and six months ended June 30, 2019 and 2018. Supplemental cash flow information related to leases for the six months ended June 30, 2019 (in millions): Cash paid for operating lease liabilities $ 15.9 Operating lease ROU assets obtained in exchange for new operating lease liabilities $ 7.6 Weighted-average remaining lease term of operating leases 4.2 years Weighted-average discount rate of operating leases 4.6 % Maturities of operating lease liabilities as of June 30, 2019 (in millions): Remainder of 2019 $ 15.3 2020 26.9 2021 22.6 2022 17.2 2023 11.8 Thereafter 9.0 Total future minimum lease payments 102.8 Less imputed interest (9.3 ) Total operating lease liabilities $ 93.5 As of June 30, 2019 , the Company has additional operating leases that have not yet commenced, with total future lease payments of approximately $4.5 million . These operating leases will commence in 2019 with lease terms of approximately 6 years . In the prior year, rent expense was $8.7 million and $15.6 million for the three and six months ended June 30, 2018 .

Acquisitions (Notes)

Acquisitions (Notes)	6 Months Ended
	Jun. 30, 2019
Business Combinations [Abstract]
Acquisitions	4. 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 $48.5 million , which included $2.5 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 is preliminary and any adjustments will be recognized prospectively. Identifiable intangible assets related to this acquisition totaled $19.0 million . 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 11. 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 and six months ended June 30, 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. Three Months Ended Six Months Ended June 30, 2018 June 30, 2018 Revenues $ 878.5 $ 1,712.7 Income from continuing operations $ 39.9 $ 74.5 Net income $ 39.8 $ 74.3 Earnings per share: Basic $ 0.76 $ 1.42 Diluted $ 0.75 $ 1.40 Weighted average number of shares outstanding 52.3 52.3 Weighted average number of shares and dilutive shares outstanding 53.1 53.0

Goodwill and Identifiable Asset

Goodwill and Identifiable Assets (Notes)	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Identifiable Intangible Assets	5. Goodwill and Identifiable Intangible Assets The changes in the carrying amount of goodwill for the six months ended June 30, 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 — — 24.7 24.7 Translation adjustment — (0.2 ) — (0.2 ) Balance as of June 30, 2019 $ 662.1 $ 230.6 $ 552.9 $ 1,445.6 Acquired intangible assets consisted of the following (in millions): June 30, 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 $ 162.4 $ 200.0 $ 346.9 $ 145.4 $ 201.5 Contractor relationships 2 - 5 years 71.0 70.4 0.6 71.1 67.1 4.0 Backlog 1 - 2.75 years 25.0 20.7 4.3 23.1 17.7 5.4 Non-compete agreements 2 - 7 years 23.6 11.9 11.7 22.1 9.9 12.2 In-use software 6 years 18.9 17.5 1.4 18.9 16.0 2.9 Favorable contracts 5 years — — — 1.4 0.9 0.5 500.9 282.9 218.0 483.5 257.0 226.5 Not subject to amortization: Trademarks (1) 258.9 — 258.9 262.2 — 262.2 Total $ 759.8 $ 282.9 $ 476.9 $ 745.7 $ 257.0 $ 488.7 ____ (1) Certain foreign trademarks totaling $3.3 million were written off during the second quarter of 2019. Estimated future amortization expense is as follows (in millions): Remainder of 2019 $ 23.6 2020 38.1 2021 32.6 2022 24.9 2023 21.7 Thereafter 77.1 $ 218.0

Long-Term Debt (Notes)

Long-Term Debt (Notes)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Long-Term Debt	6. Long-Term Debt Long-term debt consisted of the following (in millions): June 30, December 31, $200 million revolving credit facility, due March 31, 2023 $ 10.0 $ — Term B loan facility, due June 6, 2022 250.0 337.0 Term B loan facility, due April 2, 2025 787.0 787.0 1,047.0 1,124.0 Unamortized deferred loan costs (21.0 ) (23.6 ) $ 1,026.0 $ 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 percent to 0.35 percent is payable on the undrawn portion of the revolving credit facility. At June 30, 2019 , the weighted average interest rate was 4.42 percent . For the term B loan that matures on June 6, 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 June 30, 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 the Company's 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 4.50 to 1.00 as of June 30, 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 June 30, 2019 , the Company was in compliance with its debt covenants; its ratio of consolidated secured debt to consolidated EBITDA was 2.40 to 1.00 and it had $186.1 million of available borrowing capacity under its revolving credit facility. The Company has 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 June 30, 2019 and December 31, 2018 were $3.9 million and $4.4 million

Commitments and Contingencies (

Commitments and Contingencies (Notes)	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. 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 Company’s deferred compensation plan liability was $10.8 million and $6.2 million at June 30, 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 12. Fair Value Measurements ). During the quarter, the former CEO of the Company resigned and was subsequently terminated in accordance with his employment agreement. As a result, the Company recorded a one-time charge of approximately $5.3 million , which included $1.8 million in severance that will be paid over an 18-month period. Legal Proceedings The Company is involved in various legal proceedings, claims and litigation arising in the ordinary course of business. The Company does not believe that the disposition of matters that are pending or asserted will have a material effect on its condensed consolidated financial statements.

Revenues (Notes)

Revenues (Notes)	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenues	8. 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 $8.9 million and $9.8 million at June 30, 2019 and December 31, 2018 , respectively. Contract liabilities are included in other current liabilities on the condensed consolidated balance sheets and are generally recognized as revenues within three months from the balance sheet date. The allowance for doubtful accounts was $4.7 million at June 30, 2019 and $4.8 million at December 31, 2018

Income Taxes (Notes)

Income Taxes (Notes)	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes

Earnings Per Share (Notes)

Earnings Per Share (Notes)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Earnings per share	10. 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 Six Months Ended June 30, June 30, 2019 2018 2019 2018 Weighted average number of common shares outstanding used to compute basic earnings per share 52.8 52.3 52.7 52.2 Dilutive effect of stock-based awards 0.6 0.7 0.6 0.7 Number of shares used to compute diluted earnings per share 53.4 53.0 53.3 52.9 During the three and six months ended June 30, 2019 , there were 0.2 million and 0.3 million share equivalents outstanding that were excluded from the computation of diluted earnings per share because they were anti-dilutive when applying the treasury stock method. During the three and six months ended June 30, 2018 the amount of anti-dilutive share equivalents outstanding were insignificant.

Segment Reporting (Notes)

Segment Reporting (Notes)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Segment Reporting	11. 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 Six Months Ended June 30, June 30, 2019 2018 2019 2018 Apex: Revenues $ 628.5 $ 567.6 $ 1,234.6 $ 1,106.1 Gross profit 187.8 169.7 363.2 328.3 Operating income 72.9 64.9 133.9 121.2 Amortization 5.5 6.6 11.5 13.1 Oxford: Revenues $ 153.2 $ 155.8 $ 302.8 $ 302.5 Gross profit 62.5 65.5 121.4 124.6 Operating income 11.0 14.8 22.7 24.6 Amortization 1.0 1.0 2.0 2.1 ECS: Revenues $ 190.6 $ 155.1 $ 358.6 $ 155.1 Gross profit 34.9 28.7 64.5 28.7 Operating income 10.9 3.7 17.8 3.7 Amortization 6.6 10.9 13.4 10.9 Corporate: Operating loss (1) $ (21.5 ) $ (17.7 ) $ (38.4 ) $ (38.1 ) Consolidated: Revenues $ 972.3 $ 878.5 $ 1,896.0 $ 1,563.7 Gross profit 285.2 263.9 549.1 481.6 Operating income 73.3 65.7 136.0 111.4 Amortization 13.1 18.5 26.9 26.1 _____________ (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 revenues disaggregated by type (in millions): Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Apex: Assignment $ 613.0 $ 553.7 $ 1,205.2 $ 1,078.6 Permanent placement 15.5 13.9 29.4 27.5 $ 628.5 $ 567.6 $ 1,234.6 $ 1,106.1 Oxford: Assignment $ 131.4 $ 130.3 $ 260.8 $ 255.7 Permanent placement 21.8 25.5 42.0 46.8 $ 153.2 $ 155.8 $ 302.8 $ 302.5 ECS: Firm-fixed-price $ 46.1 $ 44.8 $ 89.4 $ 44.8 Time and materials 70.8 49.0 132.2 49.0 Cost-plus-fixed-fee 73.7 61.3 137.0 61.3 $ 190.6 $ 155.1 $ 358.6 $ 155.1 Consolidated $ 972.3 $ 878.5 $ 1,896.0 $ 1,563.7 The Company operates internationally, with operations mainly in the United States. The following table presents revenues by geographic location (in millions): Three Months Ended Six Months Ended June 30, June 30, 2019 % 2018 % 2019 % 2018 % Revenues: Domestic $ 929.8 95.6 % $ 838.0 95.4 % $ 1,810.9 95.5 % $ 1,485.3 95.0 % Foreign 42.5 4.4 % 40.5 4.6 % 85.1 4.5 % 78.4 5.0 % $ 972.3 100 % $ 878.5 100 % $ 1,896.0 100 % $ 1,563.7 100 % The following table presents the ECS segment revenues by customer type (in millions): Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Department of Defense and Intelligence Agencies $ 107.6 $ 95.5 $ 203.6 $ 95.5 Federal Civilian 71.3 51.0 131.5 51.0 Commercial and Other 11.7 8.6 23.5 8.6 $ 190.6 $ 155.1 $ 358.6 $ 155.1

Fair Value Measurements (Notes)

Fair Value Measurements (Notes)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	12. 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 $1.0 billion as of June 30, 2019 , excluding the $21.0 million of unamortized deferred loan costs (see Note 6. 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 $10.8 million and $6.2 million at June 30, 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). Included in selling, general and administrative expenses in the three and six months ended June 30, 2019 , is a $3.3 million charge related to management’s decision to no longer use certain foreign trademarks. There were no other fair value adjustments for non-financial assets or liabilities the three and six months ended June 30, 2019 and 2018 .

Leases (Policies)

Leases (Policies)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Lessee, Leases [Policy Text Block]	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 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.

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Lease, Cost	Components of lease expense were as follows (in millions): Three Months Ended Six Months Ended June 30, 2019 June 30, 2019 Operating lease expense $ 8.0 $ 15.9 Short-term lease expense 0.4 0.8 Variable lease expense 1.2 2.3 Total lease expense $ 9.6 $ 19.0
Cash Flow, Supplemental Disclosures	Supplemental cash flow information related to leases for the six months ended June 30, 2019 (in millions): Cash paid for operating lease liabilities $ 15.9 Operating lease ROU assets obtained in exchange for new operating lease liabilities $ 7.6 Weighted-average remaining lease term of operating leases 4.2 years Weighted-average discount rate of operating leases 4.6 %
Lessee, Operating Lease, Liability, Maturity	Maturities of operating lease liabilities as of June 30, 2019 (in millions): Remainder of 2019 $ 15.3 2020 26.9 2021 22.6 2022 17.2 2023 11.8 Thereafter 9.0 Total future minimum lease payments 102.8 Less imputed interest (9.3 ) Total operating lease liabilities $ 93.5

Acquisitions Business Acquisiti

Acquisitions Business Acquisition (Tables)	6 Months Ended
	Jun. 30, 2019
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Information [Table Text Block]	The summary below (in millions, except for per share data) presents pro forma unaudited condensed consolidated results of operations for the three and six months ended June 30, 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. Three Months Ended Six Months Ended June 30, 2018 June 30, 2018 Revenues $ 878.5 $ 1,712.7 Income from continuing operations $ 39.9 $ 74.5 Net income $ 39.8 $ 74.3 Earnings per share: Basic $ 0.76 $ 1.42 Diluted $ 0.75 $ 1.40 Weighted average number of shares outstanding 52.3 52.3 Weighted average number of shares and dilutive shares outstanding 53.1 53.0

Goodwill and Identifiable Ass_2

Goodwill and Identifiable Assets (Tables)	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The changes in the carrying amount of goodwill for the six months ended June 30, 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 — — 24.7 24.7 Translation adjustment — (0.2 ) — (0.2 ) Balance as of June 30, 2019 $ 662.1 $ 230.6 $ 552.9 $ 1,445.6
Schedule of Acquired Intangible Assets	Acquired intangible assets consisted of the following (in millions): June 30, 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 $ 162.4 $ 200.0 $ 346.9 $ 145.4 $ 201.5 Contractor relationships 2 - 5 years 71.0 70.4 0.6 71.1 67.1 4.0 Backlog 1 - 2.75 years 25.0 20.7 4.3 23.1 17.7 5.4 Non-compete agreements 2 - 7 years 23.6 11.9 11.7 22.1 9.9 12.2 In-use software 6 years 18.9 17.5 1.4 18.9 16.0 2.9 Favorable contracts 5 years — — — 1.4 0.9 0.5 500.9 282.9 218.0 483.5 257.0 226.5 Not subject to amortization: Trademarks (1) 258.9 — 258.9 262.2 — 262.2 Total $ 759.8 $ 282.9 $ 476.9 $ 745.7 $ 257.0 $ 488.7
Schedule of Estimated Future Amortization Expense	Estimated future amortization expense is as follows (in millions): Remainder of 2019 $ 23.6 2020 38.1 2021 32.6 2022 24.9 2023 21.7 Thereafter 77.1 $ 218.0

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt consisted of the following (in millions): June 30, December 31, $200 million revolving credit facility, due March 31, 2023 $ 10.0 $ — Term B loan facility, due June 6, 2022 250.0 337.0 Term B loan facility, due April 2, 2025 787.0 787.0 1,047.0 1,124.0 Unamortized deferred loan costs (21.0 ) (23.6 ) $ 1,026.0 $ 1,100.4

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 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 Six Months Ended June 30, June 30, 2019 2018 2019 2018 Weighted average number of common shares outstanding used to compute basic earnings per share 52.8 52.3 52.7 52.2 Dilutive effect of stock-based awards 0.6 0.7 0.6 0.7 Number of shares used to compute diluted earnings per share 53.4 53.0 53.3 52.9

Segment Reporting (Tables)

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reporting Information [Line Items]
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 Six Months Ended June 30, June 30, 2019 2018 2019 2018 Apex: Revenues $ 628.5 $ 567.6 $ 1,234.6 $ 1,106.1 Gross profit 187.8 169.7 363.2 328.3 Operating income 72.9 64.9 133.9 121.2 Amortization 5.5 6.6 11.5 13.1 Oxford: Revenues $ 153.2 $ 155.8 $ 302.8 $ 302.5 Gross profit 62.5 65.5 121.4 124.6 Operating income 11.0 14.8 22.7 24.6 Amortization 1.0 1.0 2.0 2.1 ECS: Revenues $ 190.6 $ 155.1 $ 358.6 $ 155.1 Gross profit 34.9 28.7 64.5 28.7 Operating income 10.9 3.7 17.8 3.7 Amortization 6.6 10.9 13.4 10.9 Corporate: Operating loss (1) $ (21.5 ) $ (17.7 ) $ (38.4 ) $ (38.1 ) Consolidated: Revenues $ 972.3 $ 878.5 $ 1,896.0 $ 1,563.7 Gross profit 285.2 263.9 549.1 481.6 Operating income 73.3 65.7 136.0 111.4 Amortization 13.1 18.5 26.9 26.1 _____________ (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.
Disaggregation of Revenue	The following table presents revenues disaggregated by type (in millions): Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Apex: Assignment $ 613.0 $ 553.7 $ 1,205.2 $ 1,078.6 Permanent placement 15.5 13.9 29.4 27.5 $ 628.5 $ 567.6 $ 1,234.6 $ 1,106.1 Oxford: Assignment $ 131.4 $ 130.3 $ 260.8 $ 255.7 Permanent placement 21.8 25.5 42.0 46.8 $ 153.2 $ 155.8 $ 302.8 $ 302.5 ECS: Firm-fixed-price $ 46.1 $ 44.8 $ 89.4 $ 44.8 Time and materials 70.8 49.0 132.2 49.0 Cost-plus-fixed-fee 73.7 61.3 137.0 61.3 $ 190.6 $ 155.1 $ 358.6 $ 155.1 Consolidated $ 972.3 $ 878.5 $ 1,896.0 $ 1,563.7
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 Six Months Ended June 30, June 30, 2019 % 2018 % 2019 % 2018 % Revenues: Domestic $ 929.8 95.6 % $ 838.0 95.4 % $ 1,810.9 95.5 % $ 1,485.3 95.0 % Foreign 42.5 4.4 % 40.5 4.6 % 85.1 4.5 % 78.4 5.0 % $ 972.3 100 % $ 878.5 100 % $ 1,896.0 100 % $ 1,563.7 100 %
Revenue from External Customers by Products and Services	The following table presents the ECS segment revenues by customer type (in millions): Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Department of Defense and Intelligence Agencies $ 107.6 $ 95.5 $ 203.6 $ 95.5 Federal Civilian 71.3 51.0 131.5 51.0 Commercial and Other 11.7 8.6 23.5 8.6 $ 190.6 $ 155.1 $ 358.6 $ 155.1

Leases (Details)

Leases (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)property	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)property	Jun. 30, 2018USD ($)	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)
Other Commitments [Line Items]
Operating lease right of use assets	$ 87.7		$ 87.7		$ 93.9	$ 0
Operating lease liability	$ 93.5		$ 93.5		$ 99.4
Number of Leased Properties Owned by Related Parties | property	2		2
Costs and Expenses, Related Party	$ 0.3		$ 0.6	$ 0.3
Lessee, Operating Lease, Leases Not Yet Commenced, Value	$ 4.5		$ 4.5
Lessee, Operating Lease, Leases Not yet Commenced, Term of Contract	6 years		6 years
Operating Leases, Rent Expense		$ 8.7		$ 15.6

Lease, Cost (Details)

Lease, Cost (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Lease, Cost [Abstract]
Operating Lease, Expense	$ 8	$ 15.9
Short-term Lease, Expense	0.4	0.8
Variable Lease, Expense	1.2	2.3
Total lease expense	$ 9.6	$ 19

Leases Supplemental Information

Leases Supplemental Information (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)Rate
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Cash paid for operating lease liabilities	$ 15.9
Operating lease right of use assets obtained in exchange for new operating leases	$ 7.6
Operating Lease, Weighted Average Remaining Lease Term	4 years 2 months 12 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	Jun. 30, 2019	Jan. 01, 2019
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remainder of 2019	$ 15.3
2020	26.9
2021	22.6
2022	17.2
2023	11.8
Thereafter	9
Total future minimum lease payments	102.8
Less Imputed interest	(9.3)
Operating lease liability	$ 93.5	$ 99.4

Leases Lease Terms (Details)

Leases Lease Terms (Details)	Jun. 30, 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 ($) $ / shares in Units, shares in Millions, $ in Millions	Jan. 25, 2019	Apr. 02, 2018	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross		$ 775
Cash paid for acquisitions, net of cash acquired				$ 48.5	$ 760.5
Goodwill				$ 1,445.6		$ 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	$ 2.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets	$ 19
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
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
Business Acquisition, Pro Forma Revenue			$ 878.5		1,712.7
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax			39.9		74.5
Business Acquisition, Pro Forma Net Income (Loss)			$ 39.8		$ 74.3
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax, Per Share, Basic			$ 0.76		$ 1.42
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax, Per Share, Diluted			$ 0.75		$ 1.40
Weighted Average Basic Shares Outstanding, Pro Forma			52.3		52.3
Pro Forma Weighted Average Shares Outstanding, Diluted			53.1		53

Goodwill and Identifiable Ass_3

Goodwill and Identifiable Assets (Goodwill) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Apr. 02, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Gross goodwill	$ 1,445.6		$ 1,421.1		$ 894.1
Goodwill, Acquired During Period	24.7	$ 528.2
Translation adjustment	(0.2)	(1.2)
Goodwill	1,445.6		1,421.1
Apex
Goodwill [Roll Forward]
Gross goodwill	662.1		662.1		662.1
Oxford
Goodwill [Roll Forward]
Gross goodwill	230.6		230.8		$ 232
Translation adjustment	(0.2)	(1.2)
ECS
Goodwill [Roll Forward]
Gross goodwill	552.9		$ 528.2
DHA | DHA
Goodwill [Roll Forward]
Goodwill, Acquired During Period	$ 24.7
ECS
Goodwill [Roll Forward]
Goodwill				$ 528.2
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	6 Months Ended
	Jun. 30, 2019		Dec. 31, 2018
Intangible assets subject to amortization:
Gross Carrying Amount	$ 500.9		$ 483.5
Accumulated Amortization	282.9		257
Net Carrying Amount	218		226.5
Intangible assets not subject to amortization:
Trademarks, Carrying Amount	258.9	[1]	262.2
Write-off of Intangible Assets (Excluding Goodwill)	3.3
Intangible Assets, Gross (Excluding Goodwill)	759.8		745.7
Intangible Assets, Net (Excluding Goodwill)	476.9		488.7
Customer and Contractual Relationships
Intangible assets subject to amortization:
Gross Carrying Amount	362.4		346.9
Accumulated Amortization	162.4		145.4
Net Carrying Amount	$ 200		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		71.1
Accumulated Amortization	70.4		67.1
Net Carrying Amount	$ 0.6		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 subject to amortization:
Gross Carrying Amount	$ 25		23.1
Accumulated Amortization	20.7		17.7
Net Carrying Amount	$ 4.3		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	11.9		9.9
Net Carrying Amount	$ 11.7		12.2
Noncompete Agreements | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	2 years
Noncompete Agreements | Maximum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years
In-use software
Intangible assets subject to amortization:
Gross Carrying Amount	$ 18.9		18.9
Accumulated Amortization	17.5		16
Net Carrying Amount	$ 1.4		2.9
In-use software | Minimum [Member]
Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	6 years
Favorable Contracts
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
[1]	Certain foreign trademarks totaling $3.3 million were written off during the second quarter of 2019.

Goodwill and Identifiable Ass_5

Goodwill and Identifiable Assets (Future Amortization Expense) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of 2019	$ 23.6
2020	38.1
2021	32.6
2022	24.9
2023	21.7
Thereafter	77.1
Net Carrying Amount	$ 218	$ 226.5

Long-Term Debt Schedule (Detail

Long-Term Debt Schedule (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Secured Debt	$ 1,047	$ 1,124
Unamortized deferred loan costs	(21)	(23.6)
Long-term Debt	1,026	1,100.4
$200 Million Revolving Credit Facility, Due March 2023 [Member]
Debt Instrument [Line Items]
Secured Debt	10	0
$825 Million Term B Loan Facility, due June 2022 [Member]
Debt Instrument [Line Items]
Secured Debt	250	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	6 Months Ended
	Jun. 30, 2019USD ($)Rate	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Unamortized deferred loan costs | $	$ 21	$ 23.6
Long-term Debt | $	1,026	1,100.4
Contractual Quarterly Payments | $	$ 2.1
Leverage Ratio	2.40
Letters of Credit Outstanding, Amount | $	$ 3.9	$ 4.4
Maximum [Member]
Debt Instrument [Line Items]
Leverage Ratio	4.50%
Leverage Ratio in Latest Year of Debt Term	3.75%
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	4.42%
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 | $	$ 186.1

Commitments and Contingencies_2

Commitments and Contingencies (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Other Commitments [Line Items]
Deferred Compensation Liability, Noncurrent	$ 10.8	$ 6.2
One-time CEO transition cost	5.3
Severance Costs	$ 1.8

Revenues (Details)

Revenues (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Deferred Revenue	$ 8.9	$ 9.8
Accounts Receivable, Allowance for Credit Loss, Current	$ 4.7	$ 4.8

Earnings Per Share (Details)

Earnings Per Share (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.2		0.3
Weighted Average Number of Shares Outstanding Reconciliation
Weighted average number of common shares outstanding used to compute basic earnings per share	52.8	52.3	52.7	52.2
Dilutive effect of stock-based awards	0.6	0.7	0.6	0.7
Number of shares used to compute diluted earnings per share	53.4	53	53.3	52.9

Segment Reporting (Segment Repo

Segment Reporting (Segment Reporting Information) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Revenues		$ 972.3	$ 878.5	$ 1,896	$ 1,563.7
Gross Profit:
Total Gross Profit		285.2	263.9	549.1	481.6
Operating Income (Loss):
Total Operating Income		73.3	65.7	136	111.4
Amortization of Intangible Assets		13.1	18.5	26.9	26.1
Apex
Revenues:
Revenues		628.5	567.6	1,234.6	1,106.1
Gross Profit:
Total Gross Profit		187.8	169.7	363.2	328.3
Operating Income (Loss):
Total Operating Income		72.9	64.9	133.9	121.2
Amortization of Intangible Assets		5.5	6.6	11.5	13.1
Oxford
Revenues:
Revenues		153.2	155.8	302.8	302.5
Gross Profit:
Total Gross Profit		62.5	65.5	121.4	124.6
Operating Income (Loss):
Total Operating Income		11	14.8	22.7	24.6
Amortization of Intangible Assets		1	1	2	2.1
ECS
Revenues:
Revenues		190.6	155.1	358.6	155.1
Gross Profit:
Total Gross Profit		34.9	28.7	64.5	28.7
Operating Income (Loss):
Total Operating Income		10.9	3.7	17.8	3.7
Amortization of Intangible Assets		6.6	10.9	13.4	10.9
Corporate
Operating Income (Loss):
Total Operating Income	[1]	(21.5)	(17.7)	(38.4)	(38.1)
Assignment | Apex
Revenues:
Revenues		613	553.7	1,205.2	1,078.6
Assignment | Oxford
Revenues:
Revenues		131.4	130.3	260.8	255.7
Permanent Placement | Apex
Revenues:
Revenues		15.5	13.9	29.4	27.5
Permanent Placement | Oxford
Revenues:
Revenues		21.8	25.5	42	46.8
Fixed-price Contract | ECS
Revenues:
Revenues		46.1	44.8	89.4	44.8
Time-and-materials Contract | ECS
Revenues:
Revenues		70.8	49	132.2	49
Cost-plus-fixed-fee Contract | ECS
Revenues:
Revenues		$ 73.7	$ 61.3	$ 137	$ 61.3
[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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues from External Customers [Line Items]
Revenues	$ 972.3	$ 878.5	$ 1,896	$ 1,563.7
Revenue as Percentage of Consolidated Revenue	100.00%	100.00%	100.00%	100.00%
Domestic
Revenues from External Customers [Line Items]
Revenues	$ 929.8	$ 838	$ 1,810.9	$ 1,485.3
Revenue as Percentage of Consolidated Revenue	95.60%	95.40%	95.50%	95.00%
Foreign
Revenues from External Customers [Line Items]
Revenues	$ 42.5	$ 40.5	$ 85.1	$ 78.4
Revenue as Percentage of Consolidated Revenue	4.40%	4.60%	4.50%	5.00%

Segment Reporting Revenue by Cu

Segment Reporting Revenue by Customer Type (details) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue from External Customer [Line Items]
Revenues	$ 972.3	$ 878.5	$ 1,896	$ 1,563.7
Department of Defense and Intelligence Agencies
Revenue from External Customer [Line Items]
Revenues	107.6	95.5	203.6	95.5
Federal Civilian
Revenue from External Customer [Line Items]
Revenues	71.3	51	131.5	51
Commercial and Other
Revenue from External Customer [Line Items]
Revenues	11.7	8.6	23.5	8.6
ECS
Revenue from External Customer [Line Items]
Revenues	$ 190.6	$ 155.1	$ 358.6	$ 155.1

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Inputs, Liabilities, Quantitative Information) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Fair Value Inputs, Liabilities, Quantitative Information
Unamortized deferred loan costs	$ 21	$ 23.6
Write-off of Intangible Assets (Excluding Goodwill)	3.3
Level 1 Inputs
Fair Value Inputs, Liabilities, Quantitative Information
Long-term debt, fair value	1,000
Deferred Compensation Plan Assets	$ 10.8	$ 6.2