ASGN (ASGN) 10-Q 9 Aug 16 2016 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2016	Aug. 04, 2016
Entity Information [Line Items]
Entity Registrant Name	ON ASSIGNMENT INC
Entity Central Index Key	890,564
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		53,348,114

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash	$ 34,782	$ 23,869
Accounts receivable, net of allowance of $7,758 and $6,682, respectively	383,722	354,808
Prepaid expenses and income taxes	7,822	12,686
Workerscompensationreceivable	12,652	13,238
Other current assets	3,248	9,607
Total current assets	442,226	414,208
Property and equipment, net	56,020	53,196
Goodwill	874,919	874,906
Identifiable intangible assets, net	397,787	417,925
Other non-current assets	6,763	7,072
Total assets	1,777,715	1,767,307
Current liabilities:
Accounts payable	5,554	9,132
Accrued payroll and contract professional pay	118,113	88,100
Workers’ compensation loss reserves	14,110	15,020
Income taxes payable	9,583	673
Other current liabilities	30,247	47,425
Total current liabilities	177,607	160,350
Long-term debt	691,930	755,508
Deferred income tax liabilities	61,553	61,539
Other long-term liabilities	5,694	5,116
Total liabilities	936,784	982,513
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred stock, $0.01 par value, 1,000,000 shares authorized, no shares issued	0	0
Common stock, $0.01 par value, 75,000,000 shares authorized, 53,490,539 and 53,024,972 issued and outstanding, respectively	535	530
Paid-in capital	557,970	542,859
Retained earnings	290,328	249,567
Accumulated other comprehensive loss	(7,902)	(8,162)
Total stockholders’ equity	840,931	784,794
Total liabilities and stockholders’ equity	$ 1,777,715	$ 1,767,307

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Accounts receivable, allowance	$ 7,758	$ 6,682
Stockholders’ equity:
Preferred Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred Stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred Stock, shares issued (in shares)	0	0
Preferred Stock, shares outstanding (in shares)	0	0
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized (in shares)	75,000,000	75,000,000
Common Stock, shares issued (in shares)	53,490,539	53,024,972
Common Stock: shares outstanding (in shares)	53,490,539	53,024,972

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenues	$ 608,088	$ 485,323	$ 1,190,128	$ 915,368
Cost of services	406,002	326,789	800,260	620,959
Gross profit	202,086	158,534	389,868	294,409
Selling, general and administrative expenses	141,350	118,867	281,231	224,802
Amortization of intangible assets	10,032	6,957	20,176	11,826
Operating income	50,704	32,710	88,461	57,781
Interest expense, net	(7,959)	(4,736)	(16,984)	(7,803)
Write-off of loan costs	0	3,751	0	3,751
Income before income taxes	42,745	24,223	71,477	46,227
Provision for income taxes	16,732	9,888	28,116	18,869
Income from continuing operations	26,013	14,335	43,361	27,358
Gain on sale of discontinued operations, net of income taxes	0	0	0	25,703
Income (loss) from discontinued operations, net of income taxes	(9)	(83)	44	326
Net income	$ 26,004	$ 14,252	$ 43,405	$ 53,387
Basic earnings per common share:
Income from continuing operations	$ 0.49	$ 0.28	$ 0.81	$ 0.53
Discontinued operations	0	(0.01)	0	0.50
Net income	0.49	0.27	0.81	1.03
Diluted earnings per common share:
Income from continuing operations	0.48	0.27	0.81	0.52
Discontinued operations	0	0	0	0.50
Net income	$ 0.48	$ 0.27	$ 0.81	$ 1.02
Number of shares and share equivalents used to calculate earnings per share:
Basic	53,422	51,978	53,284	51,749
Diluted	53,911	52,633	53,783	52,435
Reconciliation of net income to comprehensive income:
Net income	$ 26,004	$ 14,252	$ 43,405	$ 53,387
Changes in fair value of derivative, net of tax	0	75	0	122
Foreign currency translation adjustment	(1,083)	828	260	(2,896)
Comprehensive income	$ 24,921	$ 15,155	$ 43,665	$ 50,613

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash Flows from Operating Activities:
Net income	$ 43,405	$ 53,387
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of discontinued operations, net of income taxes	0	(25,703)
Depreciation and amortization	30,831	19,813
Stock-based compensation	13,458	9,190
Provision for Doubtful Accounts	5,925	4,776
Write-off of loan costs	0	3,751
Gross excess tax benefits from stock-based compensation (2)	(2,478)	(2,640)
Fair value adjustment for contingent consideration	613	512
Workers’ compensation provision	1,062	993
Other	2,013	935
Changes in operating assets and liabilities:
Accounts receivable	(34,559)	(24,401)
Prepaid expenses and income taxes	4,862	7,165
Accounts payable	(3,180)	(158)
Accrued payroll and contract professional pay	29,961	13,293
Income taxes payable	11,054	(10,165)
Workers’ compensation loss reserves	(1,372)	(834)
Other Payments to Acquire Businesses	(1,937)	0
Other	(2,012)	2,506
Net cash provided by operating activities	97,646	52,420
Cash Flows from Investing Activities:
Cash paid for property and equipment	(13,909)	(13,331)
Cash received from sale of discontinued operations, net	6,000	115,440
Payments to Acquire Businesses, Net of Cash Acquired	0	552,794
Other	(350)	(584)
Net cash provided by (used in) investing activities	(8,259)	(451,269)
Cash Flows from Financing Activities:
Principal payments of long-term debt	(72,000)	(440,125)
Proceeds from Issuance of Long-term Debt	7,000	875,000
Proceeds from option exercises and employee stock purchase plan	5,921	3,802
Payment of employment taxes related to release of restricted stock awards	(5,266)	(5,537)
Gross excess tax benefits from stock-based compensation (2)	2,478	2,640
Repurchase of common stock	(2,787)	(1,645)
Debt issuance or amendment costs	0	(23,893)
Payments of Merger Related Costs, Financing Activities	13,814	0
Net cash used in financing activities	(78,468)	410,242
Effect of exchange rate changes on cash and cash equivalents	(6)	(1,244)
Net Increase (Decrease) in Cash and Cash Equivalents	10,913	10,149
Cash and Cash Equivalents at Beginning of Year	23,869	31,714
Cash and Cash Equivalents at End of Period	34,782	41,863
Supplemental Disclosure of Cash Flow Information:
Income taxes	10,855	20,418
Interest	14,297	6,798
Supplemental Disclosure of Non-Cash Transactions:
Acquisition of property and equipment through accounts payable	574	1,627
unsettled repurchases of common stock	$ 802	$ 0

Financial Statement Presentatio

Financial Statement Presentation	6 Months Ended
	Jun. 30, 2016
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, 2015 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 On Assignment, Inc. and its subsidiaries (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, 2015 (" 2015 10-K").

Accounting Standards Updates No

Accounting Standards Updates Note	6 Months Ended
	Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounting Standards Update	2. Accounting Standards Update In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842) , which is intended to improve financial reporting about leasing transactions. This standard requires a lessee to record on the balance sheet the assets and liabilities for the rights and obligations created by lease terms of more than 12 months. It is effective for annual periods (including interim periods) beginning after December 15, 2018, and early adoption is permitted. The Company is currently evaluating the impact the provisions of ASU 2016-02 will have on its consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation - Stock Compensation (Topic 718) , which is intended to simplify the accounting for the taxes related to stock-based compensation, including adjustments to how excess tax benefits and a company's payments for tax withholdings should be classified. It is effective for annual periods (including interim periods) beginning after December 15, 2016, and early adoption is permitted. The Company is currently evaluating the impact the provisions of ASU 2016-09 will have on its consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which outlines a comprehensive new revenue recognition model designed to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606)-Principal versus Agent Considerations (Reporting Revenue Gross versus Net) , which further clarifies the implementation guidance on principal versus agent considerations contained in ASU 2014-09. In April 2016, the FASB issued ASU No. 2016-10, Revenue from Contracts with Customers (Topic 606)-Identifying Performance Obligations and Licensing , which further clarifies the implementation guidance relating to identifying performance obligations and the licensing implementation guidance. In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers (Topic 606)-Narrow-Scope Improvements and Practical Expedients , which further clarifies guidance on collectability, noncash consideration, presentation of sales tax, practical expedients, and transition. These standards, pursuant to ASU No. 2015-14, Revenue from Contracts with Customers-Deferral of the Effective Date (Topic 606) issued by the FASB in August 2015, will be effective for annual periods (including interim periods) beginning after December 15, 2017. The Company is currently evaluating the impact these new standards will have on its consolidated financial statements.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2016
Acquisitions [Abstract]
Business Combination Disclosure [Text Block]	3. Acquisitions On June 5, 2015 , the Company acquired all of the outstanding shares of the holding company for Creative Circle, LLC ("Creative Circle"). Creative Circle, which is headquartered in Los Angeles, California , was purchased to expand the Company’s technical and creative staffing services . The purchase price consisted of $540.0 million cash, $30.2 million of common stock ( 794,700 shares of the Company’s common stock), and estimated future contingent consideration which was valued at $13.8 million in the purchase price allocation. Acquisition expenses of approximately $5.7 million were expensed in 2015 and are included in selling, general and administrative ("SG&A") expenses. The final value of the contingent consideration was $15.8 million , an increase of $2.0 million from the initial valuation. This increase consisted of (i) accretion of discount, as the initial value was recorded on a discounted basis and (ii) an increase in the obligation due to higher than expected post-acquisition performance of the acquired business. The $15.8 million obligation was paid in the second quarter of 2016, of which $13.8 million was included in cash used in financing activities and $2.0 million in cash used in operating activities. On April 14, 2015 , the Company acquired all of the outstanding shares of LabResource B.V. ("LabResource") headquartered in Amsterdam, Netherlands for $12.7 million . LabResource was purchased to expand the Company's life sciences staffing business in Europe . Acquisition expenses of approximately $0.4 million were expensed in 2015 and are included in SG&A expenses. The results of operations for these acquisitions have been combined with those of the Company from the acquisition date. The summary below (in thousands, except for per share data) presents pro forma unaudited consolidated results of operations for the six months ended June 30, 2015 as if the acquisitions of Creative Circle and LabResource occurred on January 1, 2014. The pro forma financial information gives effect to certain adjustments, including amortization of intangible assets, interest expense on acquisition-related debt, provision for income taxes, and increased number of common shares as a result of the acquisitions. Acquisition-related costs are assumed to have occurred at the beginning of the year prior to acquisition. The pro forma financial information is not necessarily indicative of the operating results that would have occurred if the acquisitions had been consummated as of the date indicated, nor are they necessarily indicative of future operating results. Revenues $ 1,029,314 Income from continuing operations $ 35,095 Net income $ 61,124 Basic earnings per share: Income from continuing operations $ 0.67 Net income $ 1.16 Diluted earnings per share: Income from continuing operations $ 0.66 Net income $ 1.15 Number of shares and share equivalents used to calculate earnings per share: Basic 52,543 Diluted 53,273

Discontinued Operations

Discontinued Operations	6 Months Ended
	Jun. 30, 2016
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	4. Discontinued Operations On February 1, 2015, the Company completed the sale of its Physician Segment for $123.0 million including $6.0 million that was held in escrow and was released in March 2016. The gain on the sale was $25.7 million (net of income taxes of $14.4 million ). The operating results of this segment are presented as discontinued operations in the condensed consolidated statements of operations and comprehensive income for all periods presented. Cash flows from discontinued operations are included in the condensed consolidated statements of cash flows for the six months ended June 30, 2016 and 2015 . The cash flows that are attributable to the Physician Segment are as follows (in thousands): Six Months Ended June 30, 2016 2015 Net cash provided by (used in) operating activities $ 44 $ (1,778 ) Net cash provided by investing activities: Cash received from sale of discontinued operations, net $ 6,000 $ 115,440 Other — (14 ) Total cash provided by investing activities $ 6,000 $ 115,426 There were no significant cash flows attributable to the Physician Segment for the three months ended June 30, 2016 and 2015 . There were no significant operating results from discontinued operations after March 31, 2015. The following is a summary of the operating results of all of the Company's discontinued operations in the six months ended June 30, 2015 (in thousands): Revenues $ 12,068 Costs of services 8,653 Gross profit 3,415 Selling, general and administrative expenses 2,793 Amortization of intangible assets 155 Income before income taxes 467 Provision for income taxes 141 Income from discontinued operations, net of income taxes $ 326

Goodwill and Identifiable Asset

Goodwill and Identifiable Assets	6 Months Ended
	Jun. 30, 2016
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 year ended December 31, 2015 and the six months ended June 30, 2016 are as follows (in thousands): Apex Segment Oxford Segment Total Balance as of December 31, 2014 $ 287,951 $ 224,109 $ 512,060 Creative Circle acquisition 358,029 — 358,029 LabResource acquisition — 6,449 6,449 Translation adjustment (1,363 ) (269 ) (1,632 ) Balance as of December 31, 2015 644,617 230,289 874,906 Translation adjustment (80 ) 93 13 Balance as of June 30, 2016 $ 644,537 $ 230,382 $ 874,919 Acquired intangible assets consisted of the following (in thousands): As of June 30, 2016 As of December 31, 2015 Estimated Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Subject to amortization: Customer relationships 2 - 10 years $ 196,608 $ 86,812 $ 109,796 $ 196,472 $ 74,640 $ 121,832 Contractor relationships 2 - 5 years 69,785 45,692 24,093 69,764 40,124 29,640 Non-compete agreements 2 - 7 years 10,881 4,067 6,814 10,874 3,163 7,711 In-use software 6 years 18,900 8,091 10,809 18,900 6,516 12,384 Favorable contracts 5 years 900 313 587 900 172 728 297,074 144,975 152,099 296,910 124,615 172,295 Not subject to amortization: Trademarks 245,688 — 245,688 245,630 — 245,630 Total $ 542,762 $ 144,975 $ 397,787 $ 542,540 $ 124,615 $ 417,925 Estimated amortization expense is as follows (in thousands): Remainder of 2016 $ 19,472 2017 33,029 2018 28,905 2019 21,998 2020 14,500 Thereafter 34,195 $ 152,099

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Long-Term Debt	6. Long-Term Debt Long-term debt consisted of the following (in thousands): June 30, 2016 December 31, 2015 $150 million revolving credit facility, due June 2020 $ 25,000 $ 50,000 $825 million Term B loan facility, due June 2022 684,000 724,000 709,000 774,000 Unamortized deferred loan costs (17,070 ) (18,492 ) $ 691,930 $ 755,508 On June 5, 2015, the Company entered into a $975.0 million credit facility. The funds were used to repay the old credit facility and to fund the cash portion of the purchase of Creative Circle (see "Note 3. Acquisitions "). The facility consists of (i) an $825.0 million seven-year term B loan facility and (ii) a $150.0 million five-year revolving loan facility. Borrowings under the term B loan bear interest at LIBOR (floor of 75 basis points), plus 3.0 percent and borrowings under the revolving credit facility bear interest at LIBOR (or the bank’s base rate) plus 0.75 to 2.5 percent depending on leverage levels. A commitment fee of 0.25 to 0.40 percent is payable on the undrawn portion of the revolving credit facility. At June 30, 2016 , the weighted average interest rate was 3.7 percent . Under terms of the credit facility, the Company is required to make minimum quarterly payments of $2.1 million and mandatory prepayments, subject to specified exceptions, from excess cash flow and with the proceeds of asset sales, debt issuances and specified other events. Because of the principal payments made through June 30, 2016, no additional minimum quarterly payments are required. The Company's obligations under the credit facility are guaranteed by substantially all of its direct and indirect domestic subsidiaries and are secured by a lien on substantially all of the Company's tangible and intangible property and by a pledge of all of the equity interests in its direct and indirect domestic subsidiaries. The credit facility includes various restrictive covenants including the maximum ratio of consolidated funded debt to consolidated EBITDA ( 4.25 to 1.00 as of June 30, 2016 decreasing to 3.25 to 1.00 on March 31, 2018). 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, 2016 the Company had a ratio of consolidated funded debt to consolidated EBITDA of 2.55 to 1.00. At June 30, 2016 the Company was in compliance with all of its debt covenants and had $121.5 million of borrowing available under the revolving credit facility.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. Commitments and Contingencies The Company has entered into various non-cancelable operating leases, primarily related to its facilities and certain office equipment used in the ordinary course of business. The Company lea ses two properties owned by related parties. Rent expense for these two properties was $0.3 million for the three months ended June 30, 2016 and 2015 . Rent expense for these two properties was $0.6 million for the six months ended June 30, 2016 and 2015 . The Company carries large retention policies for its workers’ compensation liability exposures. The workers' compensation loss reserves are based upon an actuarial report obtained from a third party and determined based on claims filed and claims incurred but not reported. The Company accounts for claims incurred but not yet reported based on estimates derived from historical claims experience and current trends of industry data. Changes in estimates, differences in estimates, and actual payments for claims, are recognized in the period that the estimates changed or the payments were made. The workers' compensation loss reserves were approximately $1.5 million and $1.8 million , net of anticipated insurance and indemnification recoveries of $12.7 million and $13.2 million , at June 30, 2016 and December 31, 2015 , respectively. The Company has unused stand-by letters of credit to secure obligations for workers’ compensation claims with various insurance carriers. The unused stand-by letters of credit at June 30, 2016 and December 31, 2015 were $3.5 million . The Company is subject to contingent consideration agreements entered into in connection with certain of its acquisitions. The contingent consideration liability at June 30, 2016 was $5.8 million ( see "Note 8. Fair Value Measurements "). Certain employees participate in the Company’s Change in Control Severance Plan, or have separate agreements that provide for certain benefits in the event of termination at the Company's convenience or following a change in control, as defined by the plan or agreement. Generally, these benefits are based on the employee’s length of service and position with the Company and include, severance, continuation of health insurance and in certain cases acceleration of vesting of option or stock awards. Legal Proceedings The Company is involved in various legal proceedings, claims and litigation arising in the ordinary course of business. Based on the facts currently available, 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.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	8. Fair Value Measurements The recorded values of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximate their fair value based on their short-term nature. Long-term debt recorded in the Company’s condensed consolidated balance sheet at June 30, 2016 was $691.9 million (net of $17.1 million of unamortized deferred loan costs, see "Note 6. Long-Term Debt "). The f air value of the long-term debt at that same date was $711.0 million as determined using the quoted price technique, based on Level 2 inputs (significant observable inputs other than quoted prices for identical assets in active markets) from the fair value hierarchy, and included the yields of comparable companies with similar credit characteristics . Related to its acquisitions the Company has obligations to pay contingent consideration in cash if certain performance targets are met. The fair value of the contingent consideration is determined using an expected present value technique. Expected cash flows are determined using the probability-weighted average of possible outcomes that would occur should certain financial metrics be reached. There is no market data available to use in valuing the contingent consideration, therefore, the Company develops its own assumptions related to the future financial performance of the businesses to evaluate the fair value of these liabilities. As such, the contingent consideration is classified within Level 3 inputs (unobservable inputs) from the fair value hierarchy. The fair value of the liability for contingent consideration is established at the time of the acquisition and finalized by the end of the measurement period. The fair value i s then remeasured on a recurring basis with c hanges due to the accretion of the present value discount recorded in interest expense, and changes related to new developments in expected performance recorded in SG&A expenses. The following table summarizes the balance of the contingent consideration and changes for the periods presented (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2016 2015 2016 2015 Balance at beginning of period $ (21,594 ) $ (3,000 ) $ (20,981 ) $ (3,000 ) Additions for acquisitions — (13,814 ) — (13,814 ) Payments on contingent consideration 15,751 — 15,751 — Fair value adjustment — (512 ) (613 ) (512 ) Balance at end of period $ (5,843 ) $ (17,326 ) $ (5,843 ) $ (17,326 ) Certain assets and liabilities, such as goodwill, 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 six months ended June 30, 2016 and 2015 , no fair value adjustments were required for non-financial assets or liabilities.

Stockholders' Equity Note

Stockholders' Equity Note	6 Months Ended
	Jun. 30, 2016
Stockholders' Equity Attributable to Parent [Abstract]
Treasury Stock [Text Block]	9. Stockholders' Equity The number of shares issued upon vesting of restricted stock units, exercise of stock options and stock purchases under the Employee Stock Purchase Plan was 243,644 and 563,067 for the three and six months ended June 30, 2016, respectively. On June 10, 2016, the Board of Directors approved a new stock repurchase program, whereby the Company may repurchase up to $150.0 million of its common stock over the next two years. This program supersedes the previous $100.0 million repurchase authorization of which $98.0 million remained unused. During the three months ended June 30, 2016 , the Company repurchased 97,500 shares of its common stock at a cost of $3.6 million . All shares repurchased under this program were retired, which resulted in a reduction of $1.0 million in paid-in capital and a reduction of $2.6 million in retained earnings. The accumulated other comprehensive loss balance at June 30, 2016 and December 31, 2015 , and the activity during the six months ended June 30, 2016 , consists of foreign currency translation adjustments.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Incentive Award Plan and Employee Stock Purchase Plan	10. Stock-based Compensation Stock-based compensation expense, which is included in SG&A expenses, was $6.5 million and $5.2 million for the three months ended June 30, 2016 and 2015 , respectively and $13.5 million and $9.2 million for the six months ended June 30, 2016 and 2015 , respectively.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
Earnings per share	11. Earnings Per Share The following is a reconciliation of the shares used to compute basic and diluted earnings per share (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2016 2015 2016 2015 Weighted average number of common shares outstanding used to compute basic earnings per share 53,422 51,978 53,284 51,749 Dilutive effect of stock-based awards 489 655 499 686 Number of shares used to compute diluted earnings per share 53,911 52,633 53,783 52,435 During the six months ended June 30, 2016 , there were 445,036 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 months ended June 30, 2016 , and the three and six months ended June 30, 2015 the amount of anti-dilutive share equivalents outstanding were insignificant.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	12. Income Taxes For interim reporting periods, the Company estimates its full-year income and the related income tax expense for each jurisdiction in which the Company operates. Changes in the geographical mix, permanent differences or estimated level of annual pre-tax income can impact the Company’s actual effective rate.

Segment Reporting

Segment Reporting	6 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
Segment Reporting	13. Segment Reporting On Assignment provides services through two operating segments, the Apex Segment and the Oxford Segment, with each addressing different sectors of the professional staffing market with distinct business models attuned to those sectors. Businesses in the Apex Segment predominately serve markets with a large and local talent pool, and provide a full range of skills through a network of local offices where clients most value relationship, speed, reliability and price. The Apex Segment provides a broad spectrum of technical, scientific and creative professionals for temporary, contract-to-hire and permanent placement positions to Fortune 1000 and mid-market clients across the United States. Our businesses in this segment include Apex Systems, Lab Support and Creative Circle. Businesses in the Oxford Segment predominately serve markets with higher-end, specialized skills through a combination of national recruiting centers and local offices where clients most value the unique skill of the candidate and speed of response. The Oxford Segment provides specialized, niche staffing and consulting services in select skill and geographic markets. Our businesses in this segment include Oxford, CyberCoders and Life Sciences Europe. Effective January 1, 2016, there were two changes to the Company's segment configuration: 1) the Apex Segment now includes a small clinical research business which was previously included in the Oxford Segment, and 2) costs associated with personnel located at our Corporate office that have shared services roles and support certain of our businesses, primarily within the Oxford Segment, are now presented in the segments they support whereas previously they were presented within Corporate. For comparability purposes, prior periods have been adjusted to reflect these changes. 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 Company's management does not evaluate, manage or measure performance of segments using asset information, and such information is not readily available. Accordingly, assets by reportable segment are not disclosed. The following tables present revenues, gross profit, operating income and amortization by reportable segment (in thousands): Three Months Ended Three Months Ended June 30, 2016 June 30, 201 5 Apex Oxford Corporate (1) Total Apex Oxford Corporate (1) Total Revenues $ 453,723 $ 154,365 $ — $ 608,088 $ 340,480 $ 144,843 $ — $ 485,323 Gross profit 138,165 63,921 — 202,086 98,274 60,260 — 158,534 Operating income 50,190 13,856 (13,342 ) 50,704 34,265 15,825 (17,380 ) 32,710 Amortization 8,590 1,442 — 10,032 5,384 1,573 — 6,957 Six Months Ended Six Months Ended June 30, 2016 June 30, 201 5 Apex Oxford Corporate (1) Total Apex Oxford Corporate (1) Total Revenues $ 886,878 $ 303,250 $ — $ 1,190,128 $ 636,451 $ 278,917 $ — $ 915,368 Gross profit 264,309 125,559 — 389,868 178,426 115,983 — 294,409 Operating income 90,176 26,616 (28,331 ) 88,461 57,161 28,538 (27,918 ) 57,781 Amortization 17,180 2,996 — 20,176 8,906 2,920 — 11,826 (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 by type (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2016 % 2015 % 2016 % 2015 % Revenues: Assignment $ 574,323 94.4 % $ 456,592 94.1 % $ 1,123,875 94.4 % $ 862,733 94.2 % Permanent placement 33,765 5.6 % 28,731 5.9 % 66,253 5.6 % 52,635 5.8 % $ 608,088 100.0 % $ 485,323 100.0 % $ 1,190,128 100.0 % $ 915,368 100.0 % The Company operates internationally, with operations mainly in the United States, Europe, and Canada. The following table presents revenues by geographic location (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2016 % 2015 % 2016 % 2015 % Revenues: Domestic $ 578,165 95.1 % $ 462,989 95.4 % $ 1,132,603 95.2 % $ 873,745 95.5 % Foreign 29,923 4.9 % 22,334 4.6 % 57,525 4.8 % 41,623 4.5 % $ 608,088 100.0 % $ 485,323 100.0 % $ 1,190,128 100.0 % $ 915,368 100.0 %

Subsequent Events Note

Subsequent Events Note	6 Months Ended
	Jun. 30, 2016
Subsequent Events [Abstract]
Subsequent Events [Text Block]	14. Subsequent Events On August 5, 2016, the Company’s $975.0 million credit facility was amended whereby the interest rate for the term B loan was reduced by 25 basis points.

Acquisitions Acquisitions (Tabl

Acquisitions Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2015
Acquisitions Pro Forma Information [Abstract]
Business Acquisition, Pro Forma Information [Table Text Block]	The summary below (in thousands, except for per share data) presents pro forma unaudited consolidated results of operations for the six months ended June 30, 2015 as if the acquisitions of Creative Circle and LabResource occurred on January 1, 2014. The pro forma financial information gives effect to certain adjustments, including amortization of intangible assets, interest expense on acquisition-related debt, provision for income taxes, and increased number of common shares as a result of the acquisitions. Acquisition-related costs are assumed to have occurred at the beginning of the year prior to acquisition. The pro forma financial information is not necessarily indicative of the operating results that would have occurred if the acquisitions had been consummated as of the date indicated, nor are they necessarily indicative of future operating results. Revenues $ 1,029,314 Income from continuing operations $ 35,095 Net income $ 61,124 Basic earnings per share: Income from continuing operations $ 0.67 Net income $ 1.16 Diluted earnings per share: Income from continuing operations $ 0.66 Net income $ 1.15 Number of shares and share equivalents used to calculate earnings per share: Basic 52,543 Diluted 53,273

Discontinued Operations (Tables

Discontinued Operations (Tables)	6 Months Ended
	Jun. 30, 2016
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	The cash flows that are attributable to the Physician Segment are as follows (in thousands): Six Months Ended June 30, 2016 2015 Net cash provided by (used in) operating activities $ 44 $ (1,778 ) Net cash provided by investing activities: Cash received from sale of discontinued operations, net $ 6,000 $ 115,440 Other — (14 ) Total cash provided by investing activities $ 6,000 $ 115,426 There were no significant cash flows attributable to the Physician Segment for the three months ended June 30, 2016 and 2015 . There were no significant operating results from discontinued operations after March 31, 2015. The following is a summary of the operating results of all of the Company's discontinued operations in the six months ended June 30, 2015 (in thousands): Revenues $ 12,068 Costs of services 8,653 Gross profit 3,415 Selling, general and administrative expenses 2,793 Amortization of intangible assets 155 Income before income taxes 467 Provision for income taxes 141 Income from discontinued operations, net of income taxes $ 326

Goodwill and Identifiable Ass22

Goodwill and Identifiable Assets (Tables)	6 Months Ended
	Jun. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The changes in the carrying amount of goodwill for the year ended December 31, 2015 and the six months ended June 30, 2016 are as follows (in thousands): Apex Segment Oxford Segment Total Balance as of December 31, 2014 $ 287,951 $ 224,109 $ 512,060 Creative Circle acquisition 358,029 — 358,029 LabResource acquisition — 6,449 6,449 Translation adjustment (1,363 ) (269 ) (1,632 ) Balance as of December 31, 2015 644,617 230,289 874,906 Translation adjustment (80 ) 93 13 Balance as of June 30, 2016 $ 644,537 $ 230,382 $ 874,919
Schedule of Acquired Intangible Assets	Acquired intangible assets consisted of the following (in thousands): As of June 30, 2016 As of December 31, 2015 Estimated Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Subject to amortization: Customer relationships 2 - 10 years $ 196,608 $ 86,812 $ 109,796 $ 196,472 $ 74,640 $ 121,832 Contractor relationships 2 - 5 years 69,785 45,692 24,093 69,764 40,124 29,640 Non-compete agreements 2 - 7 years 10,881 4,067 6,814 10,874 3,163 7,711 In-use software 6 years 18,900 8,091 10,809 18,900 6,516 12,384 Favorable contracts 5 years 900 313 587 900 172 728 297,074 144,975 152,099 296,910 124,615 172,295 Not subject to amortization: Trademarks 245,688 — 245,688 245,630 — 245,630 Total $ 542,762 $ 144,975 $ 397,787 $ 542,540 $ 124,615 $ 417,925
Schedule of Estimated Future Amortization Expense	Estimated amortization expense is as follows (in thousands): Remainder of 2016 $ 19,472 2017 33,029 2018 28,905 2019 21,998 2020 14,500 Thereafter 34,195 $ 152,099

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt consisted of the following (in thousands): June 30, 2016 December 31, 2015 $150 million revolving credit facility, due June 2020 $ 25,000 $ 50,000 $825 million Term B loan facility, due June 2022 684,000 724,000 709,000 774,000 Unamortized deferred loan costs (17,070 ) (18,492 ) $ 691,930 $ 755,508

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Schedule of Reconciliations of Liabilities Measured and Carried at Fair Value on Recurring Basis, with Significant Unobservable Inputs	The following table summarizes the balance of the contingent consideration and changes for the periods presented (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2016 2015 2016 2015 Balance at beginning of period $ (21,594 ) $ (3,000 ) $ (20,981 ) $ (3,000 ) Additions for acquisitions — (13,814 ) — (13,814 ) Payments on contingent consideration 15,751 — 15,751 — Fair value adjustment — (512 ) (613 ) (512 ) Balance at end of period $ (5,843 ) $ (17,326 ) $ (5,843 ) $ (17,326 )

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2016
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 thousands): Three Months Ended Six Months Ended June 30, June 30, 2016 2015 2016 2015 Weighted average number of common shares outstanding used to compute basic earnings per share 53,422 51,978 53,284 51,749 Dilutive effect of stock-based awards 489 655 499 686 Number of shares used to compute diluted earnings per share 53,911 52,633 53,783 52,435

Segment Reporting (Tables)

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2016
Segment Reporting Information [Line Items]
Schedule of Segment Reporting Information, by Segment	Three Months Ended Three Months Ended June 30, 2016 June 30, 201 5 Apex Oxford Corporate (1) Total Apex Oxford Corporate (1) Total Revenues $ 453,723 $ 154,365 $ — $ 608,088 $ 340,480 $ 144,843 $ — $ 485,323 Gross profit 138,165 63,921 — 202,086 98,274 60,260 — 158,534 Operating income 50,190 13,856 (13,342 ) 50,704 34,265 15,825 (17,380 ) 32,710 Amortization 8,590 1,442 — 10,032 5,384 1,573 — 6,957 Six Months Ended Six Months Ended June 30, 2016 June 30, 201 5 Apex Oxford Corporate (1) Total Apex Oxford Corporate (1) Total Revenues $ 886,878 $ 303,250 $ — $ 1,190,128 $ 636,451 $ 278,917 $ — $ 915,368 Gross profit 264,309 125,559 — 389,868 178,426 115,983 — 294,409 Operating income 90,176 26,616 (28,331 ) 88,461 57,161 28,538 (27,918 ) 57,781 Amortization 17,180 2,996 — 20,176 8,906 2,920 — 11,826 (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.
Revenue by Type [Table Text Block]	The following table presents revenues by type (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2016 % 2015 % 2016 % 2015 % Revenues: Assignment $ 574,323 94.4 % $ 456,592 94.1 % $ 1,123,875 94.4 % $ 862,733 94.2 % Permanent placement 33,765 5.6 % 28,731 5.9 % 66,253 5.6 % 52,635 5.8 % $ 608,088 100.0 % $ 485,323 100.0 % $ 1,190,128 100.0 % $ 915,368 100.0 %
Schedule of Revenue by Geographical Areas	The Company operates internationally, with operations mainly in the United States, Europe, and Canada. The following table presents revenues by geographic location (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2016 % 2015 % 2016 % 2015 % Revenues: Domestic $ 578,165 95.1 % $ 462,989 95.4 % $ 1,132,603 95.2 % $ 873,745 95.5 % Foreign 29,923 4.9 % 22,334 4.6 % 57,525 4.8 % 41,623 4.5 % $ 608,088 100.0 % $ 485,323 100.0 % $ 1,190,128 100.0 % $ 915,368 100.0 %

Acquisitions Acquisitions Costs

Acquisitions Acquisitions Costs, by Acquisition (Details) - USD ($) $ in Thousands	Jun. 05, 2015	Apr. 14, 2015	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Business Acquisition [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Payments			$ 0	$ 15,751	$ 0
Other Payments to Acquire Businesses				1,937	0
Payments of Merger Related Costs, Financing Activities				13,814	$ 0
Creative Circle [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Jun. 5, 2015
Business Acquisition, Name of Acquired Entity	Creative Circle, LLC
Business Acquisition, Description of Acquired Entity	is headquartered in Los Angeles, California
Business Combination, Reason for Business Combination	was purchased to expand the Company’s technical and creative staffing services
Payments to Acquire Businesses, Gross	$ 540,000
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned	30,200
Stock Issued During Period, Shares, Acquisitions					794,700
Business Acquisition Contingent Consideration At Fair Value Accrued Earn-Out	$ 13,800
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Payments				15,751
Other Payments to Acquire Businesses				2,000
Payments of Merger Related Costs, Financing Activities				$ 13,800
Business Combination, Acquisition Related Costs					$ 5,700
LabResource [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition		Apr. 14, 2015
Business Acquisition, Name of Acquired Entity		LabResource B.V.
Business Acquisition, Description of Acquired Entity		headquartered in Amsterdam, Netherlands
Business Combination, Reason for Business Combination		expand the Company's life sciences staffing business in Europe
Payments to Acquire Businesses, Gross		$ 12,700
Business Combination, Acquisition Related Costs					$ 400

Acquisitions Business Acquisiti

Acquisitions Business Acquisition, Pro Forma Information (Details) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2015USD ($)$ / sharesshares
Business Combinations [Abstract]
Revenues | $	$ 1,029,314
Income from continuing operations | $	35,095
Net income | $	$ 61,124
Income from continuing operations	$ 0.67
Net income	1.16
Income from continuing operations	0.66
Net income	$ 1.15
Basic | shares	52,543
Diluted | shares	53,273

Discontinued Operations (Detail

Discontinued Operations (Details) - USD ($) $ in Thousands	Feb. 02, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Divestiture of Businesses	$ 123,000
Gain (Loss) on Disposition of Business		$ 0	$ 0	$ 0	$ 25,703
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation					14,400
Cash Provided by (Used in) Operating Activities, Discontinued Operations				44	(1,778)
Cash received from sale of discontinued operations, net				6,000	115,440
Other Cash Provided by (Used in) Investing Activities, Discontinued Operations				0	(14)
Cash Provided by (Used in) Investing Activities, Discontinued Operations				6,000	115,426
Disposal Group, Including Discontinued Operation, Revenue					12,068
Disposal Group Including Discontinued Operations Cost of Services					8,653
Disposal Group, Including Discontinued Operation, Gross Profit (Loss)					3,415
Disposal Group, Including Discontinued Operation, General and Administrative Expense					2,793
Disposal Group Including Discontinued Operations Amortization of Intangible Assets					155
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax					467
Discontinued Operation, Tax Effect of Discontinued Operation					141
Income (loss) from discontinued operations, net of income taxes		$ (9)	$ (83)	$ 44	$ 326

Goodwill and Identifiable Ass30

Goodwill and Identifiable Assets (Goodwill) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Roll Forward]
Gross goodwill	$ 874,919	$ 874,906	$ 512,060
Goodwill	874,919	874,906
Translation adjustment	13	(1,632)
Apex
Goodwill [Roll Forward]
Gross goodwill	644,537	644,617	287,951
Translation adjustment	(80)	(1,363)
Oxford
Goodwill [Roll Forward]
Gross goodwill	230,382	230,289	$ 224,109
Translation adjustment	$ 93	(269)
Creative Circle [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period		358,029
Creative Circle [Member] | Apex
Goodwill [Roll Forward]
Goodwill, Acquired During Period		358,029
Creative Circle [Member] | Oxford
Goodwill [Roll Forward]
Goodwill, Acquired During Period		0
LabResource [Member]
Goodwill [Roll Forward]
Goodwill, Acquired During Period		6,449
LabResource [Member] | Apex
Goodwill [Roll Forward]
Goodwill, Acquired During Period		0
LabResource [Member] | Oxford
Goodwill [Roll Forward]
Goodwill, Acquired During Period		$ 6,449

Goodwill and Identifiable Ass31

Goodwill and Identifiable Assets (Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Intangible Assets [Line Items]
Amortization of intangible assets	$ 10,032	$ 6,957	$ 20,176	$ 11,826
Intangible assets subject to amortization:
Gross Carrying Amount	297,074		297,074		$ 296,910
Accumulated Amortization	144,975		144,975		124,615
Net Carrying Amount	152,099		152,099		172,295
Intangible assets not subject to amortization:
Trademarks, Carrying Amount	245,688		245,688		245,630
Goodwill, Carrying Amount	874,919		874,919		874,906
Intangible Assets, Gross (Excluding Goodwill)	542,762		542,762		542,540
Total
Identifiable intangible assets, net	397,787		397,787		417,925
Customer relations
Intangible assets subject to amortization:
Gross Carrying Amount	196,608		196,608		196,472
Accumulated Amortization	86,812		86,812		74,640
Net Carrying Amount	109,796		$ 109,796		121,832
Customer relations | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			2 years
Customer relations | Maximum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			10 years
Contractor Relations [Member]
Intangible assets subject to amortization:
Gross Carrying Amount	69,785		$ 69,785		69,764
Accumulated Amortization	45,692		45,692		40,124
Net Carrying Amount	24,093		$ 24,093		29,640
Contractor Relations [Member] | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			2 years
Contractor Relations [Member] | Maximum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			5 years
Non-compete agreements
Intangible assets subject to amortization:
Gross Carrying Amount	10,881		$ 10,881		10,874
Accumulated Amortization	4,067		4,067		3,163
Net Carrying Amount	6,814		$ 6,814		7,711
Non-compete agreements | Minimum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			2 years
Non-compete agreements | Maximum [Member]
Intangible Assets [Line Items]
Estimated Useful Life			7 years
Computer Software, Intangible Asset [Member]
Intangible Assets [Line Items]
Estimated Useful Life			6 years
Intangible assets subject to amortization:
Gross Carrying Amount	18,900		$ 18,900		18,900
Accumulated Amortization	8,091		8,091		6,516
Net Carrying Amount	10,809		$ 10,809		12,384
Contract-Based Intangible Assets [Member]
Intangible Assets [Line Items]
Estimated Useful Life			5 years
Intangible assets subject to amortization:
Gross Carrying Amount	900		$ 900		900
Accumulated Amortization	313		313		172
Net Carrying Amount	$ 587		$ 587		$ 728

Goodwill and Identifiable Ass32

Goodwill and Identifiable Assets (Future Amortization Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 10,032	$ 6,957	$ 20,176	$ 11,826
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2,016	19,472		19,472
2,017	33,029		33,029
2,018	28,905		28,905
2,019	21,998		21,998
2,020	14,500		14,500
Thereafter	34,195		34,195
Net Carrying Amount	$ 152,099		$ 152,099		$ 172,295

Long-Term Debt Long-Term Debt S

Long-Term Debt Long-Term Debt Schedule (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Secured Debt	$ 709,000	$ 774,000
Unamortized Debt Issuance Expense	(17,070)	(18,500)
Long-term Debt	691,930	755,508
$150 Million Revolving Credit Facility, Due June 2020 [Member]
Debt Instrument [Line Items]
Secured Debt	25,000	50,000
$825 Million Term B Loan Facility, due June 2022 [Member]
Debt Instrument [Line Items]
Secured Debt	$ 684,000	$ 724,000

Long-Term Debt Long-term Debt T

Long-Term Debt Long-term Debt Text (Details) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
	Jun. 15, 2015Rate	Jun. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Dec. 31, 2015USD ($)	Jun. 05, 2015USD ($)
Debt Instrument [Line Items]
Long-term Debt		$ 691,930	$ 691,930	$ 755,508
Unamortized Debt Issuance Expense		$ 17,070	$ 17,070	$ 18,500
Debt, Weighted Average Interest Rate		3.70%	3.70%
Contractual Quarterly Payments		$ 2,100	$ 2,100
Leverage Ratio		2.55
$825 Million Term B Loan Facility, due June 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount					$ 825,000
$150 Million Revolving Credit Facility, Due June 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount					$ 150,000
Maximum [Member]
Debt Instrument [Line Items]
Leverage Ratio in Latest Year of Debt Term		3.25	3.25
Leverage Ratio			4.25
Notes Payable to Banks [Member] | Minimum [Member] | $150 Million Revolving Credit Facility, Due June 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate | Rate	0.75%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | Rate	0.25%
Notes Payable to Banks [Member] | Maximum [Member] | $150 Million Revolving Credit Facility, Due June 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate | Rate	2.50%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage | Rate	0.40%
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 | Rate	3.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity		$ 121,500	$ 121,500

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016USD ($)property	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)property	Jun. 30, 2015USD ($)	Dec. 31, 2015USD ($)
Other Commitments [Line Items]
Number of Leased Properties Owned by Related Parties | property	2		2
Costs and Expenses, Related Party	$ 300	$ 300	$ 600	$ 600
Self Insurance Reserve	1,500		1,500		$ 1,800
Estimated Insurance Recoveries	12,652		12,652		13,238
Letters of Credit Outstanding, Amount	$ 3,500		$ 3,500		$ 3,500

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Inputs, Liabilities, Quantitative Information) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Fair Value Inputs, Liabilities, Quantitative Information
Long-term Debt	$ 691,930	$ 755,508
Unamortized Debt Issuance Expense	17,070	$ 18,500
Level 2 Inputs
Fair Value Inputs, Liabilities, Quantitative Information
Long-term debt, fair value	711,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Liabilities, Quantitative Information
Obligations, Fair Value Disclosure	$ (5,800)

Fair Value Measurements (Liabil

Fair Value Measurements (Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Contingent consideration for acquisitions
Balance at beginning of period	$ (21,594)	$ (3,000)	$ (20,981)	$ (3,000)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases	0	(13,814)	0	(13,814)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Payments		0	15,751	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	0	512	613	512
Balance at end of period	$ (5,843)	$ (17,326)	$ (5,843)	$ (17,326)

Stockholders' Equity Share repu

Stockholders' Equity Share repurchase and retirement (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2016	Jun. 13, 2016	Jan. 16, 2015
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Value	$ 3.6
Stock Repurchase Program, Authorized Amount		$ 150	$ 100
Stock Repurchase Program, Remaining Authorized Repurchase Amount			$ 98
Stock Repurchased During Period, Shares	97,500
Additional Paid-in Capital [Member]
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Value	$ 1
Retained Earnings [Member]
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Value	$ 2.6

Stockholders' Equity Shares iss

Stockholders' Equity Shares issued for RSU's, Options and ESPP (Details) - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016
Shares Issued for RSU's, Options and ESPP [Abstract]
Stock Issued During Period, Shares, New Issues	243,644	563,067

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Deferred Compensation Arrangement with Individual, Share-based Payments
Allocated Share-based Compensation Expense	$ 6.5	$ 5.2	$ 13.5	$ 9.2

Earnings Per Share (Details)

Earnings Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			445,036
Weighted Average Number of Shares Outstanding Reconciliation
Weighted average number of common shares outstanding used to compute basic earnings per share	53,422,000	51,978,000	53,284,000	51,749,000
Dilutive effect of stock-based awards	489,000	655,000	499,000	686,000
Number of shares used to compute diluted earnings per share	53,911,000	52,633,000	53,783,000	52,435,000

Segment Reporting (Segment Repo

Segment Reporting (Segment Reporting Information) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2016USD ($)segment	Jun. 30, 2015USD ($)
Revenues:
Revenues	$ 608,088	$ 485,323	$ 1,190,128	$ 915,368
Revenue as Percentage of Consolidated Revenue	100.00%	100.00%	100.00%	100.00%
Gross Profit:
Total Gross Profit	$ 202,086	$ 158,534	$ 389,868	$ 294,409
Operating Income (Loss):
Total Operating Income	50,704	32,710	88,461	57,781
Amortization of Intangible Assets	10,032	6,957	$ 20,176	11,826
Reportable segments (in number of segments) | segment			2
Apex
Revenues:
Revenues	453,723	340,480	$ 886,878	636,451
Gross Profit:
Total Gross Profit	138,165	98,274	264,309	178,426
Operating Income (Loss):
Total Operating Income	50,190	34,265	90,176	57,161
Amortization of Intangible Assets	8,590	5,384	17,180	8,906
Oxford
Revenues:
Revenues	154,365	144,843	303,250	278,917
Gross Profit:
Total Gross Profit	63,921	60,260	125,559	115,983
Operating Income (Loss):
Total Operating Income	13,856	15,825	26,616	28,538
Amortization of Intangible Assets	1,442	1,573	2,996	2,920
Corporate Segment [Member]
Operating Income (Loss):
Total Operating Income	(13,342)	(17,380)	(28,331)	(27,918)
Amortization of Intangible Assets	0	0	0	0
Assignment [Member]
Revenues:
Revenues	$ 574,323	$ 456,592	$ 1,123,875	$ 862,733
Revenue as Percentage of Consolidated Revenue	94.40%	94.10%	94.40%	94.20%
PermanentPlacement [Member]
Revenues:
Revenues	$ 33,765	$ 28,731	$ 66,253	$ 52,635
Revenue as Percentage of Consolidated Revenue	5.60%	5.90%	5.60%	5.80%

Segment Reporting (Revenue by G

Segment Reporting (Revenue by Geographical Areas) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenues from External Customers [Line Items]
Revenues	$ 608,088	$ 485,323	$ 1,190,128	$ 915,368
Revenue as Percentage of Consolidated Revenue	100.00%	100.00%	100.00%	100.00%
Domestic [Member]
Revenues from External Customers [Line Items]
Revenues	$ 578,165	$ 462,989	$ 1,132,603	$ 873,745
Revenue as Percentage of Consolidated Revenue	95.10%	95.40%	95.20%	95.50%
Foreign [Member]
Revenues from External Customers [Line Items]
Revenues	$ 29,923	$ 22,334	$ 57,525	$ 41,623
Revenue as Percentage of Consolidated Revenue	4.90%	4.60%	4.80%	4.50%

Subsequent Events (Details)

Subsequent Events (Details) - $825 Million Term B Loan Facility and $150 Million Revolving Credit Facility [Member] - USD ($) $ in Millions	Aug. 05, 2016	Jun. 05, 2015
Subsequent Event [Line Items]
Debt Instrument, Face Amount		$ 975
Notes Payable to Banks [Member]
Subsequent Event [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.25%