ASGN (ASGN) 10-K 3 Mar 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Jan. 31, 2014	Jun. 30, 2013
Entity Information [Line Items]	'	'	'
Entity Registrant Name	'ON ASSIGNMENT INC	'	'
Entity Central Index Key	'0000890564	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Document Type	'10-K	'	'
Document Period End Date	31-Dec-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Amendment Flag	'false	'	'
Entity Common Stock, Shares Outstanding	'	54,006,430	'
Entity Public Float	'	'	$1,236,377,419
Entity Well-known Seasoned Issuer	'No	'	'
Entity Voluntary Filers	'No	'	'
Entity Current Reporting Status	'Yes	'	'

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Current Assets:	'		'
Cash and cash equivalents	$37,350		$27,479
Accounts receivable, net of $3,067 and $3,970, respectively	262,224		245,201
Prepaid expenses	8,686		8,839
Deferred income tax assets	17,214		10,147
Workers’ compensation and medical malpractice receivable	21,200		16,442
Other	3,200		4,289
Total current assets	349,874		312,397
Property and equipment, net	38,591		26,862
Goodwill	574,948		496,158
Identifiable intangible assets, net	288,455		263,840
Other	9,326		15,206
Total Assets	1,261,194	[1]	1,114,463	[1]
Current Liabilities:	'		'
Current portion of long-term debt	10,000		10,000
Accounts payable	8,370		6,810
Accrued payroll and contract professional pay	76,556		59,962
Deferred compensation	20		10,000
Workers’ compensation and medical malpractice loss reserves	32,751		26,769
Income taxes payable	13,418		191
Other	27,906		21,437
Total current liabilities	169,021		135,169
Deferred income tax liabilities	49,584		23,009
Long-term debt, net of current portion	389,813		416,588
Other long-term liabilities	12,643		6,974
Total liabilities	621,061		581,740
Commitments and Contingencies	'		'
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, 53,926,525 and 52,960,570 issued and outstanding, respectively	539		530
Paid-in capital	493,279		471,711
Retained earnings	146,199		61,687
Accumulated other comprehensive income (loss)	116		-1,205
Total stockholders’ equity	640,133		532,723
Total Liabilities and Stockholders’ Equity	$1,261,194		$1,114,463
[1]	As of end of the year.

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]	'	'
Allowance for Doubtful Accounts Receivable, Current	$3,067,000	$3,970,000
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)	53,926,525	52,960,570
Common Stock: shares outstanding (in shares)	53,926,525	52,960,570

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]	'	'	'
Revenues	$1,631,997	$1,137,986	$515,584
Cost of services	1,143,591	782,093	337,896
Gross profit	488,406	355,893	177,688
Selling, general and administrative expenses	342,687	256,696	136,709
Amortization of intangible assets	21,751	18,016	2,346
Operating income	123,968	81,181	38,633
Interest expense, net	-15,863	-15,768	-2,936
Write-off of loan costs	-14,958	-813	0
Income before income taxes	93,147	64,600	35,697
Provision for income taxes	38,792	28,141	14,833
Income from continuing operations	54,355	36,459	20,864
Gain on sale of discontinued operations, net of income taxes	30,840	0	0
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	-683	6,194	3,433
Net income	84,512	42,653	24,297
Basic earnings per common share:	'	'	'
Income from continuing operations	$1.02	$0.78	$0.57
Income from discontinued operations	$0.56	$0.13	$0.09
Net income	$1.58	$0.91	$0.66
Diluted earnings per common share:	'	'	'
Income from continuing operations	$1	$0.76	$0.55
Income from discontinued operations	$0.55	$0.13	$0.09
Net income	$1.55	$0.89	$0.64
Number of shares and share equivalents used to calculate earnings per share:	'	'	'
Basic (in shares)	53,481	46,739	36,876
Diluted (in shares)	54,555	47,826	37,758
Reconciliation of net income to comprehensive income:	'	'	'
Net income	84,512	42,653	24,297
Changes in fair value of derivative, net of income tax of $(113), $21 and $227, respectively	193	-21	-380
Foreign currency translation adjustment	1,128	854	-1,662
Comprehensive income	$85,833	$43,486	$22,255

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]	'	'	'
Changes in fair value of derivative, tax	($113)	$21	$227

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
In Thousands, except Share data, unless otherwise specified
Balance at Dec. 31, 2010	$219,487	$365	$224,139	($5,021)	$4
Balance (in shares) at Dec. 31, 2010	'	36,398,811	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'
Exercise of common stock options (in shares)	'	293,893	'	'	'
Exercise of common stock options	1,724	2	1,722	'	'
Employee stock purchase plan (in shares)	'	187,036	'	'	'
Employee stock purchase plan	977	2	975	'	'
Stock repurchase and retirement (in shares)	'	-323,361	'	'	'
Stock repurchase and retirement	-2,230	-3	-1,985	-242	'
Stock-based compensation expense	5,868	'	5,868	'	'
Vesting of restricted stock units and restricted stock awards (in shares)	'	455,871	'	'	'
Vesting of restricted stock units and restricted stock awards	-2,219	4	-2,223	'	'
Tax deficiency from stock-based compensation	881	'	881	'	'
Fair value adjustment of derivatives, net of income tax	-380	'	'	'	-380
Translation adjustments	-1,662	'	'	'	-1,662
Net income (loss)	24,297	'	'	24,297	'
Balance at Dec. 31, 2011	246,743	370	229,377	19,034	-2,038
Balance (in shares) at Dec. 31, 2011	'	37,012,250	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'
Exercise of common stock options (in shares)	'	968,206	'	'	'
Exercise of common stock options	7,041	10	7,031	'	'
Employee stock purchase plan (in shares)	'	154,934	'	'	'
Employee stock purchase plan	1,344	2	1,342	'	'
Stock-based compensation expense	9,558	'	9,558	'	'
Vesting of restricted stock units and restricted stock awards (in shares)	'	520,652	'	'	'
Vesting of restricted stock units and restricted stock awards	-5,535	5	-5,540	'	'
Tax deficiency from stock-based compensation	4,528	'	4,528	'	'
Stock Issued During Period, Shares, Acquisitions	'	14,304,528	'	'	'
Stock Issued During Period, Value, Acquisitions	225,558	143	225,415	'	'
Fair value adjustment of derivatives, net of income tax	-21	'	'	'	-21
Translation adjustments	854	'	'	'	854
Net income (loss)	42,653	'	'	42,653	'
Balance at Dec. 31, 2012	532,723	530	471,711	61,687	-1,205
Balance (in shares) at Dec. 31, 2012	52,960,570	52,960,570	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'
Exercise of common stock options (in shares)	'	393,183	'	'	'
Exercise of common stock options	3,198	3	3,195	'	'
Employee stock purchase plan (in shares)	'	203,200	'	'	'
Employee stock purchase plan	3,856	2	3,854	'	'
Stock-based compensation expense	13,911	'	13,911	'	'
Vesting of restricted stock units and restricted stock awards (in shares)	'	369,572	'	'	'
Vesting of restricted stock units and restricted stock awards	-4,693	4	-4,697	'	'
Tax deficiency from stock-based compensation	5,305	'	5,305	'	'
Fair value adjustment of derivatives, net of income tax	193	'	'	'	193
Translation adjustments	1,128	'	'	'	1,128
Net income (loss)	84,512	'	'	84,512	'
Balance at Dec. 31, 2013	$640,133	$539	$493,279	$146,199	$116
Balance (in shares) at Dec. 31, 2013	53,926,525	53,926,525	'	'	'

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows from Operating Activities:	'	'	'
Net income	$84,512	$42,653	$24,297
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	-30,840	0	0
Depreciation and amortization	29,882	24,702	8,851
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'	'
Provision for deferred income taxes	4,111	4,970	3,748
Stock-based compensation	14,411	9,706	6,927
Write off of Deferred Debt Issuance Cost	14,958	813	0
Gross excess tax benefits from stock-based compensation	-5,308	-4,638	-1,113
Workers’ compensation and medical malpractice provision	5,956	3,594	3,196
Other Noncash Income (Expense)	66	-619	178
Changes in operating assets and liabilities, net of effects of acquisitions:	'	'	'
Accounts receivable	-20,155	-18,604	-25,079
Prepaid expenses and income taxes	6,628	2,166	-2,925
Accounts payable	-1,580	1,987	-1,812
Accrued payroll and contract professional pay	17,554	-28,053	6,400
Deferred compensation	-9,980	312	-303
Other	441	470	1,410
Net cash provided by operating activities	110,524	40,697	23,419
Cash Flows from Investing Activities:	'	'	'
Cash paid for property and equipment	-16,531	-14,354	-8,411
Cash paid for acquisitions, net of cash acquired	-110,700	-347,743	-32,818
Cash received from sale of discontinued operations, net	59,899	'	'
Other	-1,023	-869	109
Net cash used in investing activities	-68,355	-362,966	-41,120
Cash Flows from Financing Activities:	'	'	'
Principal payments of long-term debt	-456,275	-173,163	-20,500
Proceeds from term debt	429,500	513,000	40,500
Proceeds from stock transactions	7,054	8,384	2,701
Payment of employment taxes related to release of restricted stock awards	-7,600	-2,627	-2,214
Gross excess tax benefits from stock-based compensation	5,308	4,638	1,113
Repurchase of common stock	'	'	-2,230
Debt issuance or amendment costs	-6,938	-17,113	-87
Payments of other long-term liabilities	-3,425	-1,198	-1,731
Other	-14	-43	-43
Net cash provided by (used in) financing activities	-32,390	331,878	17,509
Effect of exchange rate changes on cash and cash equivalents	92	131	-478
Net Increase (Decrease) in Cash and Cash Equivalents	9,871	9,740	-670
Cash and Cash Equivalents at Beginning of Year	27,479	17,739	18,409
Cash and Cash Equivalents at End of Year	37,350	27,479	17,739
Supplemental Disclosure of Cash Flow Information	'	'	'
Income taxes	32,350	33,915	16,163
Interest	15,158	14,722	2,659
Non-Cash Investing and Financing Activities:	'	'	'
Equity consideration for acquisition	0	225,558	0
Payable for employment taxes withheld related to release of restricted stock awards	0	2,907	0
Accrued earn-out	7,860	0	10,346
Acquisition of property and equipment through accounts payable	594	369	324
Acquisition accounting	$0	($1,805)	$0

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Summary of Significant Accounting Policie	'
	Summary of Significant Accounting Policies.
	Principles of Consolidation. The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated.
	Use of Estimates. The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Revenue Recognition. Revenues from contract assignments, net of sales adjustments and discounts, are recognized when earned, based on hours worked by the Company’s contract professionals on a weekly basis. Conversion and direct hire fees are recognized when employment candidates begin permanent employment. The Company records a sales allowance against consolidated revenues, which is an estimate based on historical billing adjustment experience. The sales allowance is recorded as a reduction to revenues and an increase to the allowance for billing adjustments. The billing adjustment reserve includes an allowance for fallouts. Fallouts are direct hire and conversion fees that do not complete the contingency period, which is typically 90 days or less. The Company includes reimbursed expenses, in revenues and the associated amounts of reimbursable expenses in cost of services.
	The Company records revenues on a gross basis as a principal or on a net basis as an agent depending on the arrangement. The key indicators as to whether it acts as a principal or an agent are whether the Company (i) has the direct contractual relationships with its customers, (ii) bears the risks and rewards of the transactions, and (iii) has the discretion to select the contract professionals and establish their price.
	Income Taxes. Income taxes are accounted for using the liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that a portion of the deferred tax asset will not be realized.
	The Company makes a comprehensive review of its uncertain tax positions regularly. An uncertain tax position represents the Company’s expected treatment of a tax position taken in a filed return, or planned to be taken in a future tax return or claim that has not been reflected in measuring income tax expense for financial reporting purposes. In general, until these positions are sustained by the taxing authorities or statutes expire for the year that the position was taken, the Company does not recognize the tax benefits resulting from such positions and reports the tax effects as a liability for uncertain tax positions.
	Foreign Currency Translation. The functional currency of the Company’s foreign operations is their local currency, and as such, their assets and liabilities are translated into U.S. dollars at the rate of exchange in effect on the balance sheet date. Revenue and expenses are translated at the average rates of exchange prevailing during each monthly period. The related translation adjustments are recorded as cumulative foreign currency translation adjustments in accumulated other comprehensive income as a separate component of stockholders’ equity. Gains and losses resulting from foreign currency transactions, which are not material, are included in Selling, general and administrative (SG&A) expenses in the Consolidated Statements of Operations and Comprehensive Income.
	Cash and Cash Equivalents. The Company considers all highly liquid investments with a maturity of three months or less on the date of purchase to be cash equivalents.
	Allowance for Doubtful Accounts and Billing Adjustments. The Company estimates an allowance for doubtful accounts and an allowance for billing adjustments related to trade receivables based on an analysis of historical collection and billing adjustment experience. The Company applies bad debt percentages based on experience to the outstanding accounts receivable balances at the end of the period, as well as analyzes specific reserves as needed. Impaired receivables, or portions thereof, are written-off when deemed uncollectible.
	Property and Equipment. Property and equipment are stated at cost. Depreciation and amortization are provided using the straight-line method over the estimated useful lives of the related assets, generally three to five years. Leasehold improvements are amortized over the shorter of the life of the related asset or the remaining term of the lease. Costs associated with customized internal-use software systems that have reached the application development stage and meet recoverability tests are capitalized. Such capitalized costs include external direct costs utilized in developing or obtaining the applications and payroll and payroll-related expenses for employees who are directly associated with the application development.
	Goodwill and Identifiable Intangible Assets. Goodwill and intangible assets with indefinite lives are tested for impairment on an annual basis as of October 31, and for goodwill whenever an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount and for indefinite lived intangibles, if events or changes in circumstances indicate that it is more likely than not that the asset is impaired.
	Intangible assets with indefinite lives consist of trademarks. The Company tests trademarks for impairment on an annual basis, on October 31. In order to test the trademarks for impairment, the Company determines the fair value of the trademarks and compares such amount to its carrying value. The fair value of the trademarks is determined using a projected discounted cash flow analysis based on the relief-from-royalty approach. The principal factors used in the discounted cash flow analysis requiring judgment are projected net sales, discount rate, royalty rate and terminal value assumption. The royalty rate used in the analysis is based on transactions that have occurred in our industry. Intangible assets having finite lives are amortized over their useful lives and are tested for recoverability whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Customer relations are amortized using an accelerated method. Contractor relations and non-compete agreements are amortized using the straight-line method. The Company did not have any impairments of indefinite lived or finite lived intangibles in 2013, 2012, or 2011.
	Goodwill is tested for impairment using a two-step process in which the first step compares the fair value of a reporting unit, which is generally an operating segment or one level below the operating segment level, which is a business and for which discrete financial information is available and reviewed by segment management, to the reporting unit's carrying value. The second step measures the amount of impairment by comparing the implied fair value of the respective reporting unit's goodwill with the carrying value of that goodwill. The goodwill impairment loss is measured by the amount the carrying value of goodwill exceeds the implied fair value of goodwill.
	The Company performed the step one goodwill impairment tests for each reporting unit as of October 31, 2013 as this is the annual impairment test date. Based upon the annual goodwill impairment tests in 2013, 2012 and 2011, there was no goodwill impairment charge.
	Impairment or Disposal of Long-Lived Assets. The Company evaluates long-lived assets, other than goodwill and identifiable intangible assets with indefinite lives, for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. An impairment loss is recognized when the sum of the undiscounted future cash flows is less than the carrying amount of the asset, in which case a write-down is recorded to reduce the related asset to its estimated fair value.
	Workers’ Compensation and Medical Malpractice Loss Reserves. The Company carries retention policies for its workers’ compensation liability and medical malpractice liability exposures. In connection with these programs, the Company pays a base premium plus actual losses incurred, not to exceed certain stop-loss limits. The Company is insured for losses above these limits, both per occurrence and in the aggregate. The workers' compensation and medical malpractice 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 and differences in estimates and actual payments for claims are recognized in the period that the estimates changed or the payments were made.
	The Company has restated certain amounts in the Consolidated Balance Sheet at December 31, 2012. The restatement had no effect on the Consolidated Statements of Operations and Comprehensive Income or Consolidated Statements of Cash Flows, as previously reported. The restatement reclassified $16.4 million of workers compensation and medical malpractice receivables recorded as an offset in the workers’ compensation and medical malpractice loss reserves to workers’ compensation and medical malpractice receivable. The workers' compensation and medical malpractice loss reserves disclosure in Note 8 “Commitments and Contingencies” has been restated to reflect the workers’ compensation and medical malpractice receivables on a gross basis at December 31, 2012. The total assets disclosure in Note 12 “Business Segments” has been restated to reflect the workers’ compensation and medical malpractice receivables on a gross basis for all periods presented.
	Contingencies. The Company records an estimated loss from a loss contingency when information available prior to issuance of its financial statements indicates it is probable that an asset has been impaired or a liability has been incurred at the date of the financial statements, and the amount of the loss can be reasonably estimated. Accounting for contingencies, such as legal settlements, workers’ compensation matters and medical malpractice insurance matters, requires the Company to use judgment.
	Business Combinations. The purchase price of an acquisition is allocated to the underlying assets acquired and liabilities assumed based upon their estimated fair values at the date of acquisition. To the extent the purchase price exceeds the fair value of the net identifiable tangible and intangible assets acquired and liabilities assumed, such excess is allocated to goodwill. The Company determines the estimated fair values after review and consideration of relevant information including discounted cash flows, quoted market prices and estimates made by management. Accordingly, these can be affected by contract performance and other factors over time, which may cause final amounts to differ materially from original estimates. The Company adjusts the preliminary purchase price allocation, as necessary, up to one year after the acquisition closing date if it obtains more information regarding asset valuations and liabilities assumed.
	Goodwill acquired in business combinations is assigned to the reporting unit(s) expected to benefit from the combination as of the acquisition date. Acquisition related costs are recognized separately from the acquisition and are expensed as incurred.
	Stock-Based Compensation. The Company records compensation expense for restricted stock awards and restricted stock units based on the fair market value of the awards on the date of grant. Compensation expense for performance-based awards is measured based on the amount of shares ultimately expected to vest, estimated at each reporting date based on management’s expectations regarding the relevant performance criteria. The Company accounts for stock options granted and Employee Stock Purchase plan ("ESPP") shares based on an estimated fair market value using a Black-Scholes option valuation model. This methodology requires the use of subjective assumptions including expected stock price volatility and the estimated life of each award. The fair value of equity-based compensation awards less the estimated forfeitures is amortized over the vesting period of the award.
	Concentration of Credit Risk. Financial instruments that potentially subject the Company to credit risks consist primarily of cash, cash equivalents and trade receivables. The Company places its cash and cash equivalents in low risk investments with quality credit institutions and limits the amount of credit exposure with any single institution above FDIC insured limits. Concentration of credit risk with respect to accounts receivable is limited because of the large number of geographically dispersed customers, thus spreading the trade credit risk. The Company performs ongoing credit evaluations to identify risks and maintains an allowance to address these risks.
	Derivative Instruments. The Company utilizes derivative financial instruments to manage interest rate risk. The Company does not use derivative financial instruments for trading or speculative purposes, nor does it use leveraged financial instruments.
	Advertising Costs. Advertising costs, which are expensed as incurred, were $5.0 million in 2013, $4.6 million in 2012, and $2.6 million in 2011, and are included in selling, general and adminsitrative ("SG&A") expenses.
	Reclassifications. Certain prior period amounts have been reclassified to conform to the current period financial statement presentation. These changes consisted of reclassifications to separate or combine certain line items in the accompanying consolidated balance sheets, consolidated statements of operations comprehensive income and consolidated statements of cash flows. Additionally, some reclassifications relate to the required presentation of income from discontinued operations during the years ended December 31, 2013, 2012, and 2011. Please refer to Note 4 for further details. All such reclassifications do not affect net income as presented in previous years.

Property_and_Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Property and Equipment.	'
	Property and Equipment.
	Property and equipment at December 31, 2013 and 2012 consisted of the following (in thousands):
		2013			2012
	Furniture, fixtures and equipment	$	8,409		$	6,891
	Computers and related equipment	12,155			6,918
	Computer software	37,800			32,871
	Leasehold improvements	6,059			5,417
	Work-in-progress	14,929			9,937
		79,352			62,034
	Less -- accumulated depreciation and amortization	(40,761		)	(35,172		)
		$	38,591		$	26,862
	Depreciation and amortization expense related to property and equipment was $8.0 million in 2013, $6.5 million in 2012 and $5.3 million in 2011, and is included in SG&A expenses.
	The Company has capitalized costs related to its various technology initiatives. The net book value of the property and equipment related to software development was $13.5 million as of December 31, 2013 and $12.1 million as of December 31, 2012, which includes work-in-progress of $10.0 million and $7.5 million, respectively.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Acquisitions	'
	Acquisitions.
	On December 5, 2013, the Company acquired all of the outstanding shares of CyberCoders Holdings, Inc. ("CyberCoders"), a privately-owned provider of permanent placement services headquartered in Irvine, California. The primary reason for the acquisition was to expand the Company's permanent placement services. The purchase price was $98.6 million, comprised of $93.6 million in cash paid at closing and potential future earn-out consideration of $5.0 million (the maximum earn-out opportunity is capped at $11.0 million) based on estimated financial performance of CyberCoders through 2015. Acquisition costs of approximately $1.5 million were expensed in 2013. Goodwill deductible for tax purposes is $10.3 million for this transaction. The results of operations for the acquisition have been combined with those of the Company from the acquisition date. CyberCoders revenues and net income (loss) included in the Statement of Operations for the year ended December 31, 2013 were $3.6 million and $(0.1) million, respectively.
	On December 2, 2013, the Company acquired all of the outstanding partnership interests of Whitaker Medical, LLC, a privately-owned provider of physician staffing services headquartered in Houston, Texas. The primary reason for the acquisition was to expand the Company's Physician staffing services. The purchase price was $21.3 million, comprised of $18.5 million in cash paid at closing and potential future earn-out consideration of $2.8 million (the maximum earn-out opportunity is capped at $5.0 million) based on estimated financial performance of Whitaker through 2015. Acquisition costs of approximately $0.4 million were expensed in 2013. Goodwill is deductible for tax purposes. The results of operations for the acquisition have been combined with those of the Company from the acquisition date. Whitaker revenues and net income (loss) included in the Statement of Operations for the year ended December 31, 2013 were $2.3 million and $(28,000), respectively.
	On May 15, 2012, the Company acquired all of the outstanding shares of Apex Systems, Inc., a privately-owned provider of information technology staffing headquartered in Richmond, Virginia. The primary reason for the acquisition was to expand the Company's information technology staffing services. The purchase price totaled approximately $610.8 million, comprised of $385.0 million paid in cash at closing, $0.3 million paid in the third quarter of 2012 related to the net working capital adjustments, and 14.3 million shares of common stock of the Company issued to the holders of shares of common stock and options to purchase common stock of Apex immediately prior to the effective time of the merger. Acquisition costs related to this transaction totaled approximately $9.8 million and were expensed in 2012. Goodwill and the identifiable intangible assets are deductible for tax purposes. The results of operations of Apex have been combined with those of the Company since the acquisition date.
	On July 31, 2011, the Company acquired all of the outstanding shares of HealthCare Partners, Inc. ("HCP"), a privately-owned provider of physician staffing headquartered in Atlanta, Georgia. The primary reasons for the acquisition were to expand the Physician segment business operations geographic coverage and to leverage the Company’s infrastructure. The purchase price for HCP was approximately $19.1 million comprised of $15.7 million in cash paid at closing and potential future earn-out consideration of $3.4 million (the maximum earn-out opportunity was capped at $3.7 million) based on estimated financial performance of HCP through 2013. Acquisition costs of approximately $57,000 were expensed in 2011. The Company discontinued the use of the HCP tradename during 2012. Goodwill is deductible for tax purposes. The results of operations for the acquisition have been combined with those of the Company since the acquisition date.
	On February 28, 2011, the Company acquired all of the outstanding shares of Warphi N.V. and its subsidiaries (collectively, "Valesta"), a privately-owned provider of specialized clinical research staffing headquartered in Belgium. The primary reasons for the acquisition were to expand the Life Sciences business operations and to leverage the Company’s infrastructure. The purchase price for Valesta totaled $23.7 million, comprised of $16.8 million in cash paid at closing and potential future earn-out consideration of $6.9 million (the maximum earn-out was capped at a Euro value of €5.0 million) based on estimated financial performance of Valesta through 2013. Acquisition costs of approximately $0.4 million were expensed in 2011. Goodwill is not deductible for tax purposes. The results of operations for the acquisition have been combined with those of the Company since the acquisition date.
	Assets and liabilities of the acquired companies were recorded at their estimated fair values at the dates of acquisition. The excess purchase price over the fair value of net tangible assets and identifiable intangible assets acquired has been allocated to goodwill. The fair value assigned to identifiable intangible assets was determined primarily by using a discounted cash flow method.
	The Company's allocation for the purchase price for Apex has been finalized. The Company's allocation for the purchase price of CyberCoders and Whitaker remains incomplete with respect to opening net assets, intangible assets, taxes and contingent consideration. Measurement period adjustments resulting from the finalization of the purchase price allocation will be recorded retrospectively to the acquisition date. The preliminary fair value of contingent consideration is based on the present value of the expected future payments to be made to the sellers of the acquired businesses in accordance with the respective purchase agreements. There are numerous inputs for this valuation, which the Company will finalize during the measurement period. Significant changes are likely and will change the contingent consideration and the amount allocated to goodwill. See Note 13 Fair Value Measurements for further information regarding the fair value of contingent consideration and the level 3 rollforward disclosure.
	The following tables summarize (in thousands) the purchase price allocations for the acquisitions of CyberCoders and Whitaker, which are subject to finalization during the measurement period, and Apex, HCP and Valesta:
		2013 Acquisitions								2012 Acquisition				2011 Acquisitions
		CyberCoders				Whitaker				Apex				HCP				Valesta
	Current assets	$	10,805			$	8,909			$	172,042			$	3,950			$	6,332
	Property and equipment	3,790				272				902				123				299
	Goodwill	70,527				7,452				264,590				14,398				17,911
	Identifiable intangible assets	36,450				9,760				251,555				1,784				5,679
	Other	915				568				494				13				26
	Total assets acquired	$	122,487			$	26,961			$	689,583			$	20,268			$	30,247
	Current liabilities	$	8,022			$	5,083			$	77,905			$	1,070			$	4,774
	Other	15,817				551				850				49				1,814
	Total liabilities assumed	23,839				5,634				78,755				1,119				6,588
	Total purchase price	$	98,648			$	21,327			$	610,828			$	19,149			$	23,659
	The following table summarizes (in thousands) the allocation of the purchase price among the identifiable intangible assets for the acquisitions of CyberCoders and Whitaker, which are subject to finalization during the measurement period, and Apex, HCP and Valesta:
				Identifiable Intangible Asset Value
				2013 Acquisitions								2012 Acquisition				2011 Acquisitions
		Useful life		CyberCoders				Whitaker				Apex				HCP				Valesta
	Contractor relations	2 – 5 years		$	3,900			$	1,800			$	10,589			$	814			$	266
	Customer relations	2 – 10 years		750				5,900				92,147				950				2,395
	Non-compete agreements	2 – 7 years		800				60				2,076				20				440
	In-use software	6 years		18,900				—				—				—				—
	Trademarks	indefinite		12,100				2,000				146,743				—				2,578
				$	36,450			$	9,760			$	251,555			$	1,784			$	5,679
	The summary below (in thousands, except for per share data) presents pro forma unaudited consolidated results of operations for each of the years in the period ended December 31, 2013 as if the acquisitions of HCP and Valesta occurred on January 1, 2010, the acquisition of Apex occurred on January 1, 2011, and the acquisitions of CyberCoders and Whitaker occurred on January 1, 2012. The pro forma financial information gives effect to certain adjustments, including: the amortization of intangible assets and interest expense on acquisition-related debt, changes in the management fees, and increased number of common shares as a result of the acquisition. 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 acquisition had been consummated as of the date indicated, nor are they necessarily indicative of future operating results.
		2013				2012				2011
		(unaudited)
	Revenues	$	1,717,337			$	1,494,542			$	1,234,468
	Income from continuing operations	$	59,598			$	52,538			$	22,676
	Net income	$	89,756			$	58,732			$	26,109
	Basic earnings per share:
	Income from continuing operations	$	1.11			$	1.01			$	0.44
	Net income	$	1.68			$	1.13			$	0.51
	Diluted earnings per share
	Income from continuing operations	$	1.09			$	0.99			$	0.44
	Net income	$	1.65			$	1.1			$	0.5
	Weighted average number of shares outstanding	53,481				52,103				51,180
	Weighted average number of shares and dilutive shares outstanding	54,555				53,190				52,062

Discontinued_Operations_Discon

Discontinued Operations Discontinued Operations	12 Months Ended
	Dec. 31, 2013
Discontinued Operations [Abstract]	'
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	'
	. Discontinued Operations.
	On December 2, 2013, the Company completed the sale of its Allied Healthcare division for $28.7 million in cash and recognized a gain of $16.4 million, net of income taxes of $10.4 million. The Allied Healthcare division, previously included in the Healthcare segment, has been presented as discontinued operations in our Consolidated Statements of Operations for all periods presented.
	On February 12, 2013, the Company completed the sale of the Nurse Travel division for $33.7 million in cash and recognized a gain of $14.4 million, net of income taxes of $9.1 million. The Nurse Travel division, previously included in the Healthcare segment, has been presented as discontinued operations in our Consolidated Statements of Operations for all periods presented.
	The following is a summary of Allied Healthcare's and Nurse Travel's combined operating results for each of the years in the period ended December 31, 2013 (in thousands):
		2013			2012		2011
	Revenues	$	44,569		$	101,719	$	81,697
	Income (loss) before income taxes	$	(967	)	$	10,356	$	5,766
	Provision for income taxes	$	(284	)	$	4,162	$	2,333
	Net income (loss)	$	(683	)	$	6,194	$	3,433

LongTerm_Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	Long-Term Debt.
	Long-term debt consisted of the following (in thousands):
		2013			2012
	Senior Secured Debt
	$125 million revolving credit facility, due May 2018	$	44,500		$	—
	$100 million term A loan facility, due May 2018	92,500			—
	$275 million term B loan facility, due May 2020	262,813			—
	$75 million revolving credit facility	—			—
	$100 million term A loan facility, repaid May 2013	—			92,500
	$365 million term B loan facility, repaid May 2013	—			334,088
		$	399,813		$	426,588
	On May 16, 2013, the Company entered into a new $500.0 million credit facility and repaid all borrowing under the old facility. The new facility consists of (i) a $100.0 million, five-year term A loan facility, (ii) a $275.0 million seven-year term B loan facility and (iii) a $125.0 million, five-year revolving loan facility. Under terms of the new facility, the Company has the ability to increase the loan facilities for up to $100.0 million under certain specified conditions. During 2013, we expensed unamortized capitalized loan costs of $15.0 million related to the old borrowing facility.
	Borrowings under the new facility bear interest at the Company's option, either the Eurodollar rate (LIBOR) or the base rate, plus 1.75% to 2.50% for the term A and revolving loans and LIBOR, with a floor of 1.0%, plus 2.50% for the term B loans. At December 31, 2013, borrowings on the term A loan bore interest at 2.2%, borrowings on the term B loan bore interest at 3.5%, and the revolving loan bore interest of 0.17% base rate plus 2.0%. The weighted average interest rate at December 31, 2013 was 3.0%. The commitment fee on the undrawn portion available under the revolving loan facility ranges from 0.25% to 0.40%.
	During the remainder of this fiscal year, each of the next four years and thereafter, the Company will be required to make payments as follows (in thousands):
	2014		$	10,000
	2015		10,000
	2016		10,000
	2017		10,875
	2018		99,750
	Thereafter		259,188
	Total		$	399,813
	The Company is required to make mandatory prepayments of loans under the new facility, subject to specified exceptions, from excess cash flow and with the proceeds of asset sales, debt issuances and specified other events.
	The Company's obligations under the credit facility are guaranteed by substantially all of its direct and indirect domestic subsidiaries and secured by a lien on substantially all of the Company's tangible and intangible property and by a pledge of (i) all of the equity interests in its direct and indirect domestic subsidiaries and (ii) 65% of the equity interests in its first-tier foreign subsidiaries.
	In addition to other covenants, the maximum ratio of consolidated funded debt to consolidated EBITDA steps down from 4.00:1.00 as of December 31, 2013 to 3.25:1.00 by June 30, 2015. There are limits on the Company's and its subsidiaries' ability to incur liens, incur additional indebtedness, make loans and investments, engage in mergers and acquisitions, engage in asset sales, declare dividends or redeem or repurchase capital stock, alter the business conducted by the Company and its subsidiaries, transact with affiliates, prepay, redeem or purchase subordinated debt and amend or otherwise alter debt agreements.
	At December 31, 2013 and December 31, 2012, the Company was in compliance with all of its debt covenants. At December 31, 2013, the Company had a ratio of funded debt to consolidated EBITDA of 2.20:1.00 and had $77.8 million of borrowing available under the revolving credit facility.

Goodwill_and_Identifiable_Asse

Goodwill and Identifiable Assets	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Identifiable Intangible Assets	'
	Goodwill and Other Identifiable Intangible Assets.
	The changes in the carrying amount of goodwill for the years ended December 31, 2013 and 2012 are as follows (in thousands):
		Apex			Oxford			Life Sciences			Healthcare				Physician				Total
	Balance as of December 31, 2011
	Gross goodwill	$	—		$	149,483		$	27,668		$	122,230			$	51,570			$	350,951
	Accumulated impairment loss	—			—			—			(121,717		)		—				(121,717		)
		—			149,483			27,668			513				51,570				229,234
	Apex Acquisition (see Note 3)	264,590			—			—			—				—				264,590
	Acquisition Accounting	—			—			1,814			—				(9		)		1,805
	Translation adjustment	—			—			529			—				—				529
	Balance as of December 31, 2012
	Gross goodwill	264,590			149,483			30,011			122,230				51,561				617,875
	Accumulated impairment loss	—			—			—			(121,717		)		—				(121,717		)
		264,590			149,483			30,011			513				51,561				496,158
	Whitaker acquisition (see Note 3)	—			—			—			—				7,452				7,452
	CyberCoders acquisition (see Note 3)	—			70,527			—			—				—				70,527
	Divestiture - gross goodwill	—			—			—			(121,717		)		—				(121,717		)
	Divestiture - accumulated impairment loss	—			—			—			121,717				—				121,717
	Transfers	—			513			—			(513		)		—				—
	Translation adjustment	—			—			811			—				—				811
	Balance as of December 31, 2013
	Gross goodwill	264,590			220,523			30,822			—				59,013				574,948
	Accumulated impairment	—			—			—			—				—				—
		$	264,590		$	220,523		$	30,822		$	—			$	59,013			$	574,948
	As of December 31, 2013 and December 31, 2012, the Company had the following acquired intangible assets (in thousands):
				2013										2012
			Estimated Useful Life	Gross Carrying Amount			Accumulated Amortization			Net Carrying Amount				Gross Carrying Amount				Accumulated Amortization				Net Carrying Amount
	Subject to amortization:
	Customer relations		3 months – 10 years	$	110,007		$	41,564		$	68,443			$	103,285			$	23,338			$	79,947
	Contractor relations		2 - 7 years	43,598			30,737			12,861				37,871				27,754				10,117
	Non-compete agreements		2 - 7 years	3,863			1,424			2,439				2,986				1,062				1,924
	In-use software		6 years	18,900			263			18,637				—				—				—
				176,368			73,988			102,380				144,142				52,154				91,988
	Not subject to amortization:
	Trademarks			186,075			—			186,075				171,852				—				171,852
	Goodwill			574,948			—			574,948				496,158				—				496,158
	Total			$	937,391		$	73,988		$	863,403			$	812,152			$	52,154			$	759,998
	Amortization expense for intangible assets with finite lives was $21.8 million in 2013, $18.0 million in 2012 and $2.3 million in 2011. Estimated amortization for the each of the next five fiscal years and thereafter follows (in thousands):
	2014	$	24,509
	2015	21,326
	2016	17,721
	2017	12,888
	2018	10,307
	Thereafter	15,629
		$	102,380
	Goodwill and other intangible assets having an indefinite useful life are not amortized for financial statement purposes. Goodwill and intangible assets with indefinite lives are reviewed for impairment on an annual basis as of October 31 in 2013 and as of December 31, for prior periods, and whenever certain events or changes in circumstances occur. No impairment charge was recorded for any of the reporting units during 2013, 2012 and 2011.

401k_Retirement_Savings_Plan_D

401(k) Retirement Savings Plan, Deferred Compensation Plan and Change in Control Severance Plan	12 Months Ended
	Dec. 31, 2013
Compensation Related Costs [Abstract]	'
Deferred Compensation Plans	'
	401(k) Retirement Savings Plan, Deferred Compensation Plan and Change in Control Severance Plan.
	Under the Company’s 401(k) Retirement Savings Plan, which covers eligible employees of On Assignment and its wholly-owned subsidiaries, Assignment Ready Inc., On Assignment Staffing Services, Inc., VISTA, and Oxford, eligible employees may elect to have a portion of their salary deferred and contributed to the plans. The amount of salary deferred, up to certain limits set by the IRS, is not subject to federal and state income tax at the time of deferral, but together with any earnings on deferred amounts, is subject to taxation upon distribution. The plan covers all eligible employees and permits matching or other discretionary contributions at the Company’s discretion. Eligible employees may enroll once they complete three months of service prior to the next quarterly offering. Apex sponsors a 401(k) plan for the benefit of all eligible Apex employees. Employees are eligible to participate after 12 months of service, 1,000 hours of work, and attaining the age of 18. Under the terms of the plan, employees are entitled to contribute a portion of their total compensation, within limitations established by the Internal Revenue Code. The Company pledged to make contributions to the 401(k) plans of $6.0 million in 2013 and made contributions of $3.7 million and $1.1 million in 2012 and 2011, respectively.
	Effective January 1, 1998, the Company implemented the On Assignment, Inc. Deferred Compensation Plan. On September 4, 2008, effective as of January 1, 2008, the Company amended the On Assignment Deferred Compensation Plan and adopted a new plan, called the On Assignment Deferred Compensation Plan – Effective January 1, 2008, applicable to deferrals made on or after January 1, 2005 (referred to herein as the 2008 Deferred Compensation Plan). On April 20, 2011, the Company’s Board of Directors authorized and directed the termination of the 1998 Deferred Compensation Plan and the 2008 Deferred Compensation Plan, effective May 2, 2011.
	The Company terminated its deferred compensation plans in 2012. As a result of the termination, the Company received $1.5 million related to the cash surrender value of the life insurance proceeds, which were maintained as a funding source to the deferred compensation plans, and in June 2012, distributed $1.2 million to plan participants according to the terms of the plans.
	As a result of the merger with Apex, the Company assumed a long-term incentive program, which began in 2010, that provides for a total award of up to $10.0 million to eligible employees, based on the attainment by Apex of stipulated revenues and EBITDA goals during a three-year performance period. The Company determined that it was probable that the revenue and EBITDA goals for Apex would be reached in 2012 and the Company accrued approximately $7.9 million at May 15, 2012 (the effective date of the acquisition), and $10.0 million at December 31, 2012, which is included in deferred compensation in the Consolidated Balance Sheet. The deferred compensation balance was $20,000 at December 31, 2013.
	The Company adopted the On Assignment, Inc. Change in Control Severance Plan (the "CIC Plan") to provide severance benefits for certain officers and other employees who are terminated following an acquisition of the Company. This CIC Plan was adopted as of February 12, 2004 and amended and restated on June 21, 2013. Under the CIC Plan, eligible participants who are involuntarily terminated within 18 months after a change in control, as defined in the CIC Plan will be entitled to (i) a payment equal to a portion or multiple of the employee's annual salary plus the employee's target bonus, payable in a lump sum, and (ii) a lump sum payment representing the cost of continuation of health and welfare benefits, under the Consolidated Omnibus Budget Reconciliation Act of 1985 ("COBRA"). Severance pay under the CIC Plan varies depending on the eligible employee's length of service and position with the Company.
	The Company entered into an Amended and Restated Executive Change of Control Agreement with the Chief Executive Officer on December 11, 2008, primarily for the purpose of causing his previous agreement to meet the requirements of Code Section 409A. This agreement supersedes the CIC Plan and provides, in the event of an involuntary termination occurring within six months and ten days following a change of control of the Company, that the Chief Executive Officer is entitled to the benefits including three times his salary and target bonus payments, continuation of health and welfare benefits and car allowance for up to 18 months, and payment for outplacement services. Additionally, under the arrangements, immediately prior to a change of control, all outstanding Company stock options, restricted stock and stock units held by the Chief Executive Officer will become fully vested (and, in the case of options, remain exercisable for an extended period), subject to any express limitations contained in the Chief Executive Officer's employment agreement. In addition, the agreement entitles the Chief Executive Officer to tax gross-up payments in the event that any payments are subject to “golden parachute” excise taxes under IRS Code Section 280G.
	The Company entered into an Executive Change of Control Agreement with the Chief Financial Officer on September 1, 2012. This agreement supersedes the CIC Plan and provides, in the event of an involuntary termination occurring within six months and ten days following a change of control of the Company, for benefits including salary and bonus payments, car allowance, healthcare coverage, cash payment equal to premiums for life insurance and disability insurance, and payment for outplacement services. Immediately prior to a change of control, all outstanding Company stock options, restricted stock and restricted stock units held by the officer will become fully vested (and, in the case of options, remain exercisable for an extended period). The agreement provides the Chief Financial Officer with a best pay cap reduction for any excess parachute payments under Code Section 280G unless he would receive a greater after-tax benefit without the reduction and after paying the related excise tax.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies.
	The Company leases its facilities and certain office equipment under operating leases, which expire at various dates through 2023. Certain leases contain rent escalations and/or renewal options. Rent expense for all significant leases is recognized on a straight-line basis. The balance of the deferred rent liability reflected in other current liabilities in the accompanying Consolidated Balance Sheets was $0.4 million and 0.3 million at December 31, 2013 and 2012 respectively and the balance reflected in other long-term liabilities was $3.6 million and $3.8 million, at December 31, 2013 and 2012 respectively.
	The following is a summary of specified contractual cash obligation payments by the Company, including discontinued operations, as of December 31, 2013 (in thousands):
		Operating Leases		Related Party Leases		Total
	2014	$	15,685	$	1,299	$	16,984
	2015	13,863		1,168		15,031
	2016	11,236		694		11,930
	2017	7,523		175		7,698
	2018	5,351		—		5,351
	Thereafter	8,699		—		8,699
	Total	$	62,357	$	3,336	$	65,693
	Rent expense totaled $16.6 million for 2013, $12.8 million for 2012, and $7.2 million for 2011, and is included in SG&A expenses.
	As discussed in Note 1, the Company carries large retention policies for its workers’ compensation liability and its medical malpractice exposures. The workers' compensation and medical malpractice 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 and medical malpractice loss reserves were approximately $32.8 million and $26.8 million at December 31, 2013 and 2012, respectively. Additionally, the Company has unused stand-by letters of credit outstanding to secure obligations for workers’ compensation claims with various insurance carriers. The unused stand-by letters of credit at December 31, 2013 and December 31, 2012 were $2.7 million and $2.8 million, respectively.
	The Company is subject to earn-out obligations entered into in connection with certain of its acquisitions. If the acquired businesses meet predetermined financial targets, the Company is obligated to make additional cash payments in accordance with the terms of such earn-out obligations. As of December 31, 2013, the Company has potential future earn-out obligations of approximately $16.0 million through 2015.
	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. As a result of the Apex acquisition, the Company leases two properties owned by related parties.
	At December 31, 2013 and 2012, the Company has an income tax reserve in other long-term liabilities related to uncertain tax positions of $1.6 million and $0.4 million, respectively. Income tax reserves are not set forth in the table above. The Company is unable to make reasonably reliable estimates of the period of cash settlement since the statute of limitations might expire without examination by the respective tax authority.
	Legal Proceedings
	The Company is involved in various legal proceedings, claims and litigation arising in the ordinary course of business. The Company has accrued approximately $2.1 million for a settlement, inclusive of all plaintiffs’ costs and legal expenses, to resolve an alleged class action dispute regarding the payment of certain of our nurses when we owned a Nurse Travel division from 2008 to 2013. 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 consolidated financial statements, other than described above.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes.
	The provision (benefit) for income taxes consists of the following (in thousands):
		Year Ended December 31,
		2013			2012			2011
	Current:
	Federal	$	28,142		$	17,083		$	7,723
	State	5,266			2,742			1,223
	Foreign	1,223			2,645			1,465
		34,631			22,470			10,411
	Deferred:
	Federal & State	4,245			6,235			4,354
	Foreign	(84		)	(564		)	68
		4,161			5,671			4,422
		$	38,792		$	28,141		$	14,833
	Income from continuing operations before income taxes consists of the following (in thousands):
		Year Ended December 31,
		2013			2012			2011
	United States	$	88,637		$	61,828		$	31,639
	Foreign	4,510			2,772			4,058
		$	93,147		$	64,600		$	35,697
	The components of deferred tax assets (liabilities) are as follows (in thousands):
		December 31,			December 31,
		2013			2012
	Deferred income tax assets (liabilities):
	Current:
	Allowance for doubtful accounts	$	1,578		$	1,150
	Employee related accruals	6,663			3,419
	State taxes	611			1,064
	Workers’ compensation and medical malpractice loss reserves	4,767			4,683
	Other	3,595			(169		)
		17,214			10,147
	Non-current:
	Intangibles	(49,122		)	(23,662		)
	Depreciation expense	(6,147		)	(4,449		)
	Stock-based compensation	3,761			2,852
	Net operating loss carryforwards	1,612			1,191
	Other	1,822			1,975
		(48,074		)	(22,093		)
	Valuation allowance	(1,511		)	(916		)
	Total net deferred income tax liability	$	(32,371	)	$	(12,862	)
	The reconciliation between the amount computed by applying the U.S. federal statutory tax rate of 35.0 percent to income before income taxes and the income tax provision is as follows (in thousands):
		Year Ended December 31,
		2013			2012			2011
	Income tax provision at the statutory rate	$	32,602		$	22,610		$	12,494
	State income taxes, net of federal benefit	4,039			2,555			1,283
	Disallowed meals and entertainment expenses	1,592			1,681			1,020
	Other	559			1,295			36
		$	38,792		$	28,141		$	14,833
	As of December 31, 2013, the Company had no federal net operating losses, state net operating losses of approximately $6.9 million and foreign net operating losses of approximately $6.0 million. The state net operating losses can be carried forward up to 20 years and begin expiring in 2014. The foreign net operating losses in the United Kingdom can be carried forward indefinitely and the net operating losses in Spain can be carried forward up to 18 years beginning from the first period of profits. The Company has recorded a valuation allowance of approximately $1.5 million and $0.9 million at December 31, 2013 and December 31, 2012, respectively, related to net operating loss carryforwards.
	Basis differences in investments in foreign subsidiaries primarily related to undistributed earnings amounted to approximately $17.8 million at December 31, 2013. Those earnings are considered to be indefinitely reinvested; accordingly, no provision for U.S. federal and state income taxes has been provided thereon. Upon repatriation of those earnings, in the form of dividends or otherwise, the Company would be subject to both U.S. income taxes (subject to an adjustment for foreign tax credits) and withholding taxes payable to the various foreign countries. Determination of the amount of unrecognized deferred U.S. income tax liability is not practicable due to the complexities associated with its hypothetical calculation; however, unrecognized foreign tax credit carryforwards would be available to reduce some portion of the US liability.
	The Company had gross deferred tax assets of $27.9 million and $17.7 million, and gross deferred tax liabilities of $58.8 million and $30.5 million, at December 31, 2013 and 2012, respectively. Management has determined the gross deferred tax assets are realizable.
	At December 31, 2013, 2012 and 2011, there were $1.3 million, $0.3 million and $0.2 million of unrecognized tax benefits that if recognized would affect the annual effective tax rate. The gross unrecognized tax benefit is carried in other long-term liabilities. The Company recognizes interest and penalties related to uncertain tax positions in income tax expense. The amount of interest and penalties recognized in the financial statements is not significant.
	The following is a reconciliation of the total amounts of unrecognized tax benefits (in thousands):
		Year Ended December 31,
		2013			2012			2011
	Unrecognized Tax Benefit beginning of year	$	376		$	251		$	358
	Gross increases - tax positions in prior year	1,240			159			—
	Gross decreases - tax positions in prior year	(177		)	(34		)	—
	Lapse of the statute of limitations	—			—			(107		)
	Unrecognized Tax Benefit end of year	$	1,439		$	376		$	251
	The Company believes that there will be no significant increases or decreases to unrecognized tax benefits within the next 12 months. The Company is subject to taxation in the United States and various states and foreign jurisdictions. For U.S. federal income tax, the Company remains subject to examination for 2010 and subsequent years. For major U.S. states, with few exceptions, the Company remains subject to examination for 2009 and subsequent years. Generally, for the foreign countries, the Company remains subject to examination for 2008 and subsequent years.

Earnings_per_share

Earnings per share	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Earnings per share	'
	Earnings per Share.
	Basic earnings per share are computed based upon the weighted average number of shares outstanding and diluted earnings per share are computed based upon the weighted average number of shares and dilutive share equivalents (consisting of incentive stock options, non-qualified stock options, restricted stock units, restricted stock awards and employee stock purchase plan contributions) outstanding during the periods using the treasury stock method.
	The following is a reconciliation of the shares used to compute basic and diluted earnings per share (in thousands):
		Year Ended December 31,
		2013	2012	2011
	Weighted average number of common shares	53,481	46,739	36,876
	Dilutive effect of stock-based awards	1,074	1,087	882
	Number of shares used to compute diluted earnings per share	54,555	47,826	37,758
	The following table presents the weighted average share equivalents outstanding during each period that were excluded from the computation of diluted earnings per share because the exercise price for these options was greater than the average market price of the Company’s shares of common stock during the respective periods. Also excluded from the computation of diluted earnings per share were other share equivalents that became anti-dilutive when applying the treasury stock method.
		Year Ended December 31,
		2013	2012	2011
	Anti-dilutive common share equivalents outstanding	7	83	1,039

Stockbased_Compensation_Incent

Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan	'
	Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan.
	The Company believes that stock-based compensation better aligns the interests of its employees and directors with those of its stockholders versus exclusively providing cash-based compensation. Stock-based compensation provides incentives to retain and motivate executive officers and key employees responsible for driving Company performance and maintaining important relationships that contribute to the growth of the Company.
	Compensation expense charged to operations related to stock-based compensation, which totaled $14.1 million, $9.5 million, and $6.8 million for each of the years ended December 31, 2013, 2012 and 2011, respectively, is included in the Consolidated Statements of Operations and Comprehensive Income in SG&A expenses. The Company has recognized an income tax benefit of $5.1 million, $3.5 million, and $2.5 million for the years ended December 31, 2013, 2012 and 2011, respectively in the consolidated statements of operations for stock-based compensation arrangements.
	Effective June 3, 2010, stockholders of the Company approved the adoption of the On Assignment, Inc. 2010 Incentive Award Plan, as amended and restated in June 2013 (the "2010 Plan"), which replaced the Company’s Restated 1987 Stock Option Plan (the "1987 Plan"). The 2010 Plan permits the grant of stock options, including incentive stock options, nonqualified stock options, restricted stock awards, dividend equivalent rights, stock payments, deferred stock, restricted stock units ("RSUs"), performance shares and other incentive awards, stock appreciation rights and cash awards to its employees, directors and consultants. The 2010 Plan allows for stock option awards to be granted with an exercise price equal to the closing market price of the Company’s stock at the date of grant. Stock option awards generally vest over four years of continuous service with the Company and generally have ten-year contractual terms. RSUs generally vest over a three or four year continuous service period, though individual award vesting terms vary within these parameters. Certain stock option awards and RSUs provide for accelerated vesting in the event of a change in control (see Note 7). Options or awards that are canceled or forfeited are added back to the pool of shares available for issuance under the 2010 Plan. As of December 31, 2013, there were 3,726,322 shares available for issuance under the 2010 Plan.
	Effective May 15, 2012 (amended and restated as of December 13, 2012), the Board of Directors adopted the 2012 Employment Inducement Incentive Award Plan ("2012 Inducement Award Plan"). The 2012 Inducement Award Plan includes terms similar to the 2010 Plan and allows for grants of stock to employees as employment inducement awards pursuant to NYSE rules.
	The fair value of each option award is estimated on the date of grant using a Black-Scholes option valuation model that incorporates assumptions disclosed in the table below. Expected volatility is based on historical volatility of the underlying stock for a period consistent with the expected lives of the stock options as the Company believes this is a reasonable representation of future volatility. Additionally, the Company analyzes historical stock option exercise behavior and vesting patterns for RSUs in order to estimate employee turnover rates (i.e. forfeiture rates). The forfeiture rate, set by management, is used to estimate the number of options and awards that will eventually vest and the associated impact on stock-based compensation expense. The expected life, or term, of options granted is derived from historical exercise behavior and represents the period of time that stock option awards are expected to be outstanding. The Company has selected a risk-free rate based on the implied yield available on U.S. Treasury Securities with a maturity equivalent to the options’ expected term. For RSUs, the Company records compensation expense based on the fair market value of the awards on the grant date.
	The preceding paragraphs describe the general terms of most stock-based incentive awards granted by the Company. However, the Company has granted a discrete set of stock-based awards to its Chief Executive Officer ("CEO") and other corporate officers that differ from those generally stated terms. The impact of these awards is reflected in the detailed disclosures below. All awards are subject to the officer’s continued employment through such vesting dates, however, the vesting of certain awards will accelerate upon the occurrence of a change in control of the Company and/or upon certain qualifying terminations of employment.
	CEO Awards
	On March 4, 2013, the CEO was awarded 143,182 RSUs with a grant date fair market value of $3.2 million. The award vests in three equal annual increments on January 4, 2014, January 4, 2015 and January 4, 2016, contingent upon the Company achieving certain performance objectives based on Adjusted EBITDA (earnings before interest, taxes, depreciation, and amortization of identifiable intangible assets, but excluding gains, losses or expenses associated with unusual items such as equity-based compensation expense, impairment charges and acquisition related costs) during 2013 and approved by the Compensation Committee.
	The Company granted discrete stock-based awards to its CEO as follows: (i) a market-based award in 2010 with a grant date fair market value of $0.5 million. The award was expensed over a service period of 2.6 years and the number of shares were determined by dividing $0.5 million by the closing price of the Company stock on February 1, 2013, contingent upon the achievement of defined market targets, which were met, (ii) a performance based award on March 8, 2011, which had a grant date fair market value of $1.0 million and was expensed over a service period of 9.9 months, the financial performance objectives were met by the Company during the 12-month period ending December 31, 2011, and 24,654 shares vested on December 31, 2012, and 16,772 shares vested on February 1, 2014, (iii) a performance based award on March 23, 2012, which had a grant date fair market value of $1.5 million and was expensed over a service period of 9.3 months, the performance objectives were met by the Company during the 12-month period ending December 31, 2012 and 24,654 shares vested on December 31, 2012, 16,772 shares vested on February 1, 2014 and the remaining number of shares will be determined by dividing $0.5 million by the closing price of the Company’s stock on February 1, 2015, and (iv) a performance-based award on March 4, 2013, which had a grant date fair market value of $1.0 million and was expensed over a service period of 10.1 months, the performance objectives were met by the Company during the 12-month period ending December 31, 2013, with 16,233 shares vesting on February 1, 2014 and the remaining number of shares will be determined by dividing $0.5 million by the closing price of the Company’s stock on February 1, 2015. The Company classifies these awards as liability awards until the number of shares is determined. The liability of $2.5 million related to these awards is included in other accrued expenses and other long-term liabilities in the accompanying Consolidated Balance Sheets as of December 31, 2013.
	On December 31, 2012, the CEO was awarded 39,448 RSUs with a grant date fair market value of $0.8 million, contingent upon the Company meeting certain financial performance objectives based on adjusted EBITDA approved by the Compensation Committee over the 12-month period ending December 31, 2013 and continued employment through January 1, 2014.
	On March 5, 2012, the CEO was awarded 45,372 performance-based RSUs with a grant date fair market value of $0.6 million, of which 22,686 shares vested on December 31, 2012 and 22,686 shares vested on January 4, 2014.
	On March 8, 2011, the CEO was awarded 58,754 performance-based RSUs with a grant date fair market value of $0.6 million, of which 29,377 shares vested on January 1, 2012 and 29,377 shares vested on December 31, 2012.
	On March 17, 2010, the CEO was granted 67,568 performance-based RSUs, with a grant-date fair value of $0.5 million, of which 33,784 shares vested on February 1, 2011 and 33,784 shares vested on February 1, 2012.
	On November 4, 2009, the Company entered into an employment agreement with the CEO that provided for three annual stock award grants with grant-date values of $0.8 million each, based on performance objectives for 2010 through 2012 that vested on February 1, 2011, January 1, 2012, and December 31, 2012, respectively.
	The grant-date fair value of the awards are expensed over the vesting term, based on an estimate of the percentage achievement of the applicable performance targets. All awards were subject to the CEO’s continued employment through applicable vesting dates. All awards may vest on an accelerated basis in part or in full upon the occurrence of certain events.
	Other Executive Officer Awards
	The Company records stock-based compensation expense over the vesting period of the awards based on the probability that the performance objectives will be met and that the executives will maintain their employment through the respective vesting dates.
	On March 4, 2013 the Company granted performance-based RSUs to certain other executive officers with an aggregate grant-date fair value of $1.0 million, which vested on January 2, 2014, as certain performance objectives were obtained and certified by the Compensation Committee.
	On June 1, 2013, the Company granted performance-based RSUs to certain executive officers. The aggregate grant-date fair value of these grants was $0.1 million, which vested on January 2, 2014, as certain performance objectives were obtained and certified by the Compensation Committee. On June 21, 2013, the Company granted performance-based RSUs to certain executive officers with an aggregate grant-date fair value of $0.3 million, which will vest on May 31, 2014, subject to continued employment, attaining certain performance objectives and certification by the Compensation Committee.
	On March 5, 2012, the Company granted performance-based RSUs to certain executive officers with an aggregate grant-date fair value of $0.8 million, which vested on December 31, 2012, as certain performance objectives were attained and certified by the Compensation Committee.
	On May 15, 2012, the Company granted performance-based RSUs to certain executive officers in conjunction with the acquisition of Apex. The aggregate grant-date fair value of these grants was $0.2 million, a portion of which vested on May 31, 2013, based on the percentage achievement of certain performance objectives and certified by the Compensation Committee.
	On March 8, 2011, the Company granted performance-based RSUs to certain executive officers with an aggregate grant-date fair value of $0.7 million, which vested on January 3, 2012, as certain performance objectives were attained and certified by the Compensation Committee.
	Stock Options
	The following table displays the weighted average assumptions that have been applied to estimate the fair value of stock option awards on the date of grant. During 2013, the Company did not grant any stock option awards.
			Year Ended December 31,
			2012			2011
	Dividend yield		—			—
	Risk-free interest rate		1.19	%		0.92	%
	Expected volatility		64.15	%		75.67	%
	Expected lives		7.3 years			3.6 years
	The following summarizes pricing and term information for options outstanding as of December 31, 2013:
									Options Outstanding							Options Exercisable
									Number Outstanding at		Weighted Average Remaining Contractual Life (years)		Weighted Average Exercise Price			Number Exercisable at	Weighted Average Exercise Price
	Range of Exercise Prices								31-Dec-13							31-Dec-13
	$	4.44			─		$	8.26	255,250		4.8			$	6.62	214,351		$	6.34
	8.38				─		11.39		272,121		5.1			10.9		196,831		11.08
	11.56				─		12.9		213,724		3.1			12.39		213,724		12.39
	13.31				─		13.58		43,850		3.3			13.32		43,006		13.31
	16.51				─		16.51		75,000		8.7			16.51		23,437		16.51
	$	4.44			─		$	16.51	859,945		4.8			$	10.61	691,349		$	10.34
	The following table is a summary of stock option activity under the Plan as of December 31, 2013 and changes for the year then ended:
			Incentive Stock Options		Non- Qualified Stock Options		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual			Aggregate Intrinsic Value
									Term (Years)
	Outstanding at January 1, 2013		129,423		1,156,937		$	9.83		5.6		$	13,442,000
	Exercised		-59,806		-333,377		$	8.13
	Canceled		-201		-33,031		$	9.65
	Outstanding at December 31, 2013		69,416		790,529		$	10.61		4.8		$	20,903,000
	Vested and Expected to Vest at December 31, 2013		69,416		772,942		$	10.56		4.7		$	20,521,000
	Exercisable at December 31, 2013		69,386		621,963		$	10.34		4		$	16,995,000
	There were no non-employee director stock options outstanding during the year ended December 31, 2013.
	The weighted-average grant-date fair value of options granted during the years ended December 31, 2012 and 2011 was $10.34, and $5.04 per option, respectively. The total intrinsic value of options exercised during the years ended December 31, 2013, 2012 and 2011 was $7.6 million, $9.7 million, and $1.3 million.
	As of December 31, 2013 there was unrecognized compensation expense of $0.9 million related to unvested stock options based on options that are expected to vest. The unrecognized compensation expense is expected to be recognized over a weighted-average period of 1.97 years.
	Restricted Stock Units and Restricted Stock Awards
	A summary of the status of the Company’s unvested RSUs as of December 31, 2013 and changes during the year then ended are presented below:
			Restricted Stock Units / Awards			Weighted Average Grant-Date Fair Value Per Unit / Award
	Unvested RSUs outstanding at January 1, 2013		1,390,834				$	14.31
	Granted		621,262				26.77
	Market value share count adjustment for liability awards		(55,664	)			34.92
	Vested		(538,525	)			14.76
	Forfeited		(50,669	)			15.75
	Unvested RSUs outstanding at December 31, 2013		1,367,238				$	18.9
	Unvested and expected to vest RSUs outstanding at December 31, 2013		1,201,190				$	19.12
The number of shares vested in the table above includes 168,954 shares surrendered by the employees to the Company for payment of minimum tax withholding obligations. Shares of stock withheld for purposes of satisfying minimum tax withholding obligations are again available for issuance under the Plan.
The table above includes 59,942 performance-based RSU grants to certain Apex employees on May 15, 2013. The awards vest, if the performance objective is attained, in 12 equal installments beginning on April 1, 2014 and on each quarterly anniversary thereafter, subject to continued employment through each vesting date.
Additionally, the table above includes 26,064 RSUs that were awarded to non-employee directors on August 1, 2013, of which 13,032 shares vested immediately upon issuance and the remaining shares will vest on August 1, 2014. The weighted average grant-date fair value of these awards was $30.69. There was unrecognized compensation expense of $212,391 as of December 31, 2013 related to these RSUs that will be recorded over the remaining term of seven months.
The weighted-average grant-date fair value of RSUs granted during the years ended December 31, 2013, 2012 and 2011 was $26.17, $16.01 and $9.18 per award, respectively. The total intrinsic value of RSUs vested during the years ended December 31, 2013, 2012 and 2011 was $15.0 million, $13.7 million and $6.4 million, respectively.
As of December 31, 2013, there was unrecognized compensation expense of $15.5 million related to unvested RSUs based on awards that are expected to vest. The unrecognized compensation expense is expected to be recognized over a weighted-average period of 2.0 years.
Employee Stock Purchase Plan
Effective June 3, 2010, the date of stockholder approval of the On Assignment 2010 Employee Stock Purchase Plan (the ESPP), the Company reinstated the employee stock purchase program for issuance of up to 3,500,000 shares of common stock with the first offering periods. The ESPP allows eligible employees to purchase common stock of the Company, through payroll deductions, at 85 percent of the lower of the market price on the first day or the last day of semi-annual purchase periods. The ESPP is intended to qualify as an “employee stock purchase plan” under IRS Code Section 423. Eligible employees may contribute up to a certain percentage set by the plan administrator of their eligible earnings toward the purchase of the stock (subject to certain IRS limitations).
In accordance with the ESPP, shares of common stock are transferred to participating employees at the conclusion of each six month enrollment period, which now end on the last business day of the month in March and September each year. The Company issued 203,200, 154,934, and 187,036 shares of common stock in 2013, 2012, and 2011 respectively, under the ESPP.
Compensation expense of shares purchased under the ESPP is measured based on a Black-Scholes option-pricing model. The model accounts for the discount from market value and applies an expected life in line with each six month purchase period. The weighted average fair value of stock purchased under the ESPP was $7.16, $3.53, and $2.10 for the years ended December 31, 2013, 2012, and 2011, respectively. The stock-based compensation expense related to the ESPP was $1.2 million in 2013, $0.8 million in 2012 and $0.4 million in 2011.

Business_Segments

Business Segments	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Business Segments	'
	Business Segments.
	The Company has four reportable segments: Apex, Oxford, Life Sciences, and Physician.
	The Apex segment provides mission-critical IT operations professionals for contract, contract-to-hire and permanent placement positions to Fortune 1000 and mid-market clients across the United States, and offers consulting services for other select project-based needs. Apex provides staffing and services support for companies from all major industries, including financial services, business services, consumer and industrials, technology, healthcare, government services, and communications.
	The Oxford segment provides high-end contract and direct placement services of information technology and engineering professionals with expertise in specialized information technology; software and hardware engineering; and mechanical, electrical, validation and telecommunications engineering fields.
	The Life Sciences segment provides contract, contract-to-permanent and direct placement services of laboratory and scientific professionals to the biotechnology, pharmaceutical, food and beverage, medical device, personal care, chemical and environmental industries. These contract staffing specialties include chemists, clinical research associates, clinical lab assistants, engineers, biologists, biochemists, microbiologists, molecular biologists, food scientists, regulatory affairs specialists, lab assistants and other skilled scientific professionals.
	The Physician segment provides contract and direct placement physicians to healthcare organizations. The Physician segment works with nearly all medical specialties, placing locum tenens physicians in hospitals, community-based practices, and federal, state and local facilities.
	During 2013, the Company sold its Nurse Travel line of business and most of the Allied Healthcare line of business. See Note 4 Discontinued Operations for further information. As a result of these sales, the Healthcare segment no longer exists and Health Information Management ("HIM"), formerly included in the Healthcare Segment, is included in the Oxford Segment and unallocated corporate expenses are separately disclosed in order to align with the revised internal reporting package reviewed by the Chief Operating Decision Maker. All prior periods have been restated to conform to this presentation.
	The Company’s management evaluates the performance of each segment primarily based on revenues, gross profit and operating income. The information in the following table is derived directly from the segments’ internal financial reporting used for corporate management purposes.
	The following table represents revenues, gross profit, operating income, amortization and total assets by reportable segment (in thousands):
		Year ended December 31, 2013
		Apex			Oxford			Life Sciences				Physician		Corporate			Total
	Revenues	$	942,463		$	412,189		$	171,518			$	105,827	$	—		$	1,631,997
	Gross Profit	258,150			143,334			56,308				30,614		—			488,406
	Operating income	76,971			58,990			28,354				8,852		(49,199		)	123,968
	Amortization	19,524			965			429				742		91			21,751
	Total assets (1)	656,733			365,118			128,824				110,519		—			1,261,194
		Year ended December 31, 2012
		Apex			Oxford			Life Sciences				Physician		Corporate			Total
	Revenues	$	508,743		$	363,765		$	162,799			$	102,679	$	—		$	1,137,986
	Gross Profit	140,669			127,895			55,874				31,455		—			355,893
	Operating income	36,416			56,289			25,632				9,998		(47,154		)	81,181
	Amortization	15,665			437			807				817		290			18,016
	Total assets (1)	642,594			235,099			150,696			(2)	86,074		—			1,114,463
		Year ended December 31, 2011
		Apex			Oxford			Life Sciences				Physician		Corporate			Total
	Revenues	$	—		$	279,643		$	155,324			$	80,617	$	—		$	515,584
	Gross Profit	—			99,187			52,643				25,858		—			177,688
	Operating income	—			37,676			24,883				6,699		(30,625		)	38,633
	Amortization	—			821			901				415		209			2,346
	Total assets (1)	—			221,690			119,563			(2)	86,014		—			427,267
	______
	(1) As of end of the year.
	(2) Life Sciences total assets as of December 31, 2012 and 2011 include assets related to the Healthcare segment, which were sold and included in discontinued operations in 2013. Historically, the Company has not reported Life Science and Healthcare segments' total assets separately as the operations were largely centralized.
	The Company operates internationally, with operations in the United States, Europe, Canada, China, Australia, and New Zealand. The following table represents revenues by geographic location (in thousands):
			Year Ended December 31,
			2013			2012			2011
	Revenues:
	Domestic		$	1,552,322		$	1,060,217		$	447,453
	Foreign		79,675			77,769			68,131
			$	1,631,997		$	1,137,986		$	515,584
	The following table represents long-lived assets by geographic location (in thousands):
			December 31,
			2013			2012			2011
	Long-lived Assets:
	Domestic		$	45,061		$	40,062		$	19,078
	Foreign		2,856			2,006			1,033
			$	47,917		$	42,068		$	20,111

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	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 Consolidated Balance Sheets at December 31, 2013 was $399.8 million. The fair value of the long-term debt was determined using the quoted price technique, based on Level 2 inputs including the yields of comparable companies with similar credit characteristics, was $400.2 million.
	The Company has obligations, to be paid in cash, to the former owners of CyberCoders and Whitaker, if certain future financial goals are met. The fair value of this 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 developed 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.
	In connection with estimating the fair value of the contingent consideration, the Company develops various scenarios (base case, downside case, and upside case) and weights each according to the probability of occurrence. The probabilities range from 10 percent to 60 percent, with the most significant weighting given to the base case at 60% for Whitaker and 50% for CyberCoders. These scenarios are developed based on the expected financial performance of the acquired companies, with revenue growth rates being a primary input to the calculation. These revenue growth rates range from 2.0 percent to 15.0 percent for Whitaker, and from 9.6 percent to 25.0 percent. An increase or decrease in the probability of achievement of any of these scenarios could result in a significant increase or decrease to the estimated fair value.
	The fair value is reviewed on a quarterly basis based on most recent financial performance of the most recent fiscal quarter. An analysis is performed at the end of each fiscal quarter to compare actual results to forecasted financial performance. If performance has deviated from projected levels, the valuation is updated for the latest information available.
	The significant assumptions that may materially affect the fair value are developed in conjunction with the guidance of the division presidents, division vice presidents, and chief financial officer to ensure that the most accurate and latest financial projections are used and compared with the most recent financial results in the fair value measurement.
	The liabilities for the contingent consideration were established at the time of the acquisition and are evaluated at each reporting period. The current liability is included in the Consolidated Balance Sheets in other and the non-current portion is included in other long-term liabilities. Fair value adjustments are included in the Consolidated Statements of Operations and Comprehensive Income in S&GA expenses.
	The assets and liabilities measured at fair value on a recurring basis are as follows (in thousands):
		As of December 31, 2013
		Fair Value Measurements Using									Total
		Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs
		(Level 1)			(Level 2)			(Level 3)
	Contingent consideration to be paid in cash for the acquisitions	$	—		$	—		$	(8,527	)	$	(8,527	)
		As of December 31, 2012
		Fair Value Measurements Using									Total
		Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs
		(Level 1)			(Level 2)			(Level 3)
	Contingent consideration to be paid in cash for the acquisitions	$	—		$	—		$	(7,577	)	$	(7,577	)
	Reconciliations of liabilities measured and carried at fair value on a recurring basis with the use of significant unobservable inputs (Level 3) are as follows (in thousands):
		Year Ended December 31,
		2013			2012
	Contingent consideration for acquisitions --
	Balance at beginning of year	$	(7,577	)	$	(9,856	)
	Additions for acquisitions	(7,860		)	—
	Payments on contingent consideration	3,425			1,198
	Settlements of contingent consideration	—			—
	Fair value adjustments	3,584			1,215
	Foreign currency translation adjustment	(99		)	(134		)
	Balance at end of year	$	(8,527	)	$	(7,577	)
	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 2013 and 2012, no fair value adjustments were required for non-financial assets or liabilities.

Unaudited_Quarterly_Financial_

Unaudited Quarterly Financial Results	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Unaudited Quarterly Result	'
	Unaudited Quarterly Results.
	The following tables present unaudited quarterly financial information during the years ended December 31, 2013 and 2012. In the opinion of the Company’s management, the quarterly information contains all adjustments, consisting only of normal recurring accruals, necessary for a fair presentation thereof. The operating results for any quarter are not necessarily indicative of the results for any future periods. Nurse Travel and Allied Healthcare are presented as discontinued operations for all periods presented, see Note 4 for further information regarding the divestitures.
	Subsequent to the issuance of the Company's annual report on Form 10-K for the year ended December 31, 2012 ("2012 Form 10-K"), and the consolidated financial statements included in Exhibit 99.1 of the Form 8-K filed on June 13, 2013 ("Form 8-K"), the Company identified an immaterial error in Note 16, "Unaudited Quarterly Results," of the 2012 Form 10-K and Note 17, "Unaudited Quarterly Results," of the Form 8-K. The error related to the retrospective quarterly presentation of income from continuing operations, net income and the respective per share amounts, upon finalization of the valuation of identifiable intangible assets and amortization methods for Apex, and the related tax impact. The Company considers this an immaterial misstatement and has retrospectively restated income from continuing operations, net income and the respective per share amounts for each of the quarters in the year ended December 31, 2012 in the table below. Income from continuing operations have been restated to reflect the resulting additional amortization expense of $1.6 million ($1.0 million, net of taxes), and $3.4 million ($1.9 million, net of taxes) for the quarters ended June 30, 2012, and September 30, 2012, respectively and a reduction of amortization expense of $5.0 million ($2.9 million, net of taxes) for the quarter ended December 31, 2012.
	This error had no effect on the Company's consolidated balance sheet as of December 31, 2012, the consolidated statement of operations and comprehensive income or the consolidated statement of cash flows for the year ended December 31, 2012.
	Subsequent to the issuance of the Company's quarterly report on Form 10-Q for the second quarter of 2012, the Company identified an immaterial classification error of $0.5 million related to certain vendor fees paid by Apex Systems, Inc., which we acquired in May 2012 (see Note 3 - Acquisitions). Such fees should have been recorded as revenues, rather than in costs of services. The Company considers this an immaterial reclassification and has presented the revenues and cost of services for the year ended December 31, 2012 reflecting the reclassification in the pro forma revenues in Note 3 - Acquisitions, and revenues in the table below. This reclassification has no effect on the Company's consolidated balance sheets or consolidated statement of cash flows.
		2013
		Dec. 31,		Sep. 30,		June 30,		Mar. 31,
		(in thousands, except per share data)
	Revenues	$	423,598	$	421,491	$	407,864	$	379,044
	Gross profit	$	129,753	$	127,210	$	121,332	$	110,111
	Income from continuing operations	$	17,425	$	19,471	$	7,243	$	10,216
	Income from discontinued operations, net of income taxes	14,985		679		96		14,397
	Net income	$	32,410	$	20,150	$	7,339	$	24,613
	Basic earnings per common share:
	Income from continuing operations	$	0.32	$	0.36	$	0.14	$	0.19
	Income from discontinued operations	0.28		0.02		—		0.27
	Net income	$	0.6	$	0.38	$	0.14	$	0.46
	Diluted earnings per common share:
	Income from continuing operations	$	0.32	$	0.36	$	0.13	$	0.19
	Income from discontinued operations	0.27		0.01		0.01		0.27
	Net income	$	0.59	$	0.37	$	0.14	$	0.46
		2012
		Dec. 31,		Sep. 30,		June 30,		Mar. 31,
		(in thousands, except per share data)
	Revenues	$	369,441	$	363,882	$	256,386	$	148,277
	Gross profit	$	112,054	$	112,213	$	81,509	$	50,117
	Income from continuing operations	$	12,004	$	14,078	$	5,586	$	4,791
	Income from discontinued operations, net of income taxes	2,201		1,425		1,976		592
	Net income	$	14,205	$	15,503	$	7,562	$	5,383
	Basic earnings per common share:
	Income from continuing operations	$	0.23	$	0.27	$	0.12	$	0.13
	Income from discontinued operations	0.04		0.03		0.05		0.01
	Net income	$	0.27	$	0.3	$	0.17	$	0.14
	Diluted earnings per common share:
	Income from continuing operations	$	0.22	$	0.26	$	0.12	$	0.13
	Income from discontinued operations	0.04		0.03		0.04		0.01
	Net income	$	0.26	$	0.29	$	0.16	$	0.14

Schedule_II_Valuation_and_Qual

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2013
Valuation and Qualifying Accounts [Abstract]	'
Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]	'
	Description	Balance at beginning of year		Provisions		Deductions from reserves		Balance at end of year
	Year ended December 31, 2013
	Allowance for doubtful accounts and billing adjustments	$	3,970	1,787		(2,690	)	$	3,067
	Workers’ compensation and medical malpractice loss reserves	$	26,769	5,956		26		$	32,751
	Year ended December 31, 2012
	Allowance for doubtful accounts and billing adjustments	$	2,777	(166	)	1,359		$	3,970
	Workers’ compensation and medical malpractice loss reserves	$	27,003	3,594		(3,828	)	$	26,769
	Year ended December 31, 2011
	Allowance for doubtful accounts and billing adjustments	$	2,175	1,127		(525	)	$	2,777
	Workers’ compensation and medical malpractice loss reserves	$	28,244	2,339		(3,580	)	$	27,003

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Acquisition [Policy Text Block]	'
	Assets and liabilities of the acquired companies were recorded at their estimated fair values at the dates of acquisition. The excess purchase price over the fair value of net tangible assets and identifiable intangible assets acquired has been allocated to goodwill. The fair value assigned to identifiable intangible assets was determined primarily by using a discounted cash flow method.
Principles of Consolidation	'
	Principles of Consolidation. The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated.
Use of Estimates	'
	Use of Estimates. The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Revenue Recognition	'
	Revenue Recognition. Revenues from contract assignments, net of sales adjustments and discounts, are recognized when earned, based on hours worked by the Company’s contract professionals on a weekly basis. Conversion and direct hire fees are recognized when employment candidates begin permanent employment. The Company records a sales allowance against consolidated revenues, which is an estimate based on historical billing adjustment experience. The sales allowance is recorded as a reduction to revenues and an increase to the allowance for billing adjustments. The billing adjustment reserve includes an allowance for fallouts. Fallouts are direct hire and conversion fees that do not complete the contingency period, which is typically 90 days or less. The Company includes reimbursed expenses, in revenues and the associated amounts of reimbursable expenses in cost of services.
	The Company records revenues on a gross basis as a principal or on a net basis as an agent depending on the arrangement. The key indicators as to whether it acts as a principal or an agent are whether the Company (i) has the direct contractual relationships with its customers, (ii) bears the risks and rewards of the transactions, and (iii) has the discretion to select the contract professionals and establish their price.
Income Tax	'
	Income Taxes. Income taxes are accounted for using the liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that a portion of the deferred tax asset will not be realized.
	The Company makes a comprehensive review of its uncertain tax positions regularly. An uncertain tax position represents the Company’s expected treatment of a tax position taken in a filed return, or planned to be taken in a future tax return or claim that has not been reflected in measuring income tax expense for financial reporting purposes. In general, until these positions are sustained by the taxing authorities or statutes expire for the year that the position was taken, the Company does not recognize the tax benefits resulting from such positions and reports the tax effects as a liability for uncertain tax positions.
Foreign Currency Transactions	'
	Foreign Currency Translation. The functional currency of the Company’s foreign operations is their local currency, and as such, their assets and liabilities are translated into U.S. dollars at the rate of exchange in effect on the balance sheet date. Revenue and expenses are translated at the average rates of exchange prevailing during each monthly period. The related translation adjustments are recorded as cumulative foreign currency translation adjustments in accumulated other comprehensive income as a separate component of stockholders’ equity. Gains and losses resulting from foreign currency transactions, which are not material, are included in Selling, general and administrative (SG&A) expenses in the Consolidated Statements of Operations and Comprehensive Income.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents. The Company considers all highly liquid investments with a maturity of three months or less on the date of purchase to be cash equivalents.
Allowance for Doubtful Accounts and Billing Adjustments	'
	Allowance for Doubtful Accounts and Billing Adjustments. The Company estimates an allowance for doubtful accounts and an allowance for billing adjustments related to trade receivables based on an analysis of historical collection and billing adjustment experience. The Company applies bad debt percentages based on experience to the outstanding accounts receivable balances at the end of the period, as well as analyzes specific reserves as needed. Impaired receivables, or portions thereof, are written-off when deemed uncollectible.
Property and Equipment	'
	Property and Equipment. Property and equipment are stated at cost. Depreciation and amortization are provided using the straight-line method over the estimated useful lives of the related assets, generally three to five years. Leasehold improvements are amortized over the shorter of the life of the related asset or the remaining term of the lease. Costs associated with customized internal-use software systems that have reached the application development stage and meet recoverability tests are capitalized. Such capitalized costs include external direct costs utilized in developing or obtaining the applications and payroll and payroll-related expenses for employees who are directly associated with the application development.
Goodwill and Identifiable Intangible Assets	'
	Goodwill and Identifiable Intangible Assets. Goodwill and intangible assets with indefinite lives are tested for impairment on an annual basis as of October 31, and for goodwill whenever an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount and for indefinite lived intangibles, if events or changes in circumstances indicate that it is more likely than not that the asset is impaired.
	Intangible assets with indefinite lives consist of trademarks. The Company tests trademarks for impairment on an annual basis, on October 31. In order to test the trademarks for impairment, the Company determines the fair value of the trademarks and compares such amount to its carrying value. The fair value of the trademarks is determined using a projected discounted cash flow analysis based on the relief-from-royalty approach. The principal factors used in the discounted cash flow analysis requiring judgment are projected net sales, discount rate, royalty rate and terminal value assumption. The royalty rate used in the analysis is based on transactions that have occurred in our industry. Intangible assets having finite lives are amortized over their useful lives and are tested for recoverability whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Customer relations are amortized using an accelerated method. Contractor relations and non-compete agreements are amortized using the straight-line method. The Company did not have any impairments of indefinite lived or finite lived intangibles in 2013, 2012, or 2011.
	Goodwill is tested for impairment using a two-step process in which the first step compares the fair value of a reporting unit, which is generally an operating segment or one level below the operating segment level, which is a business and for which discrete financial information is available and reviewed by segment management, to the reporting unit's carrying value. The second step measures the amount of impairment by comparing the implied fair value of the respective reporting unit's goodwill with the carrying value of that goodwill. The goodwill impairment loss is measured by the amount the carrying value of goodwill exceeds the implied fair value of goodwill.
Impairment or Disposal of Long-Lived Assets	'
	Impairment or Disposal of Long-Lived Assets. The Company evaluates long-lived assets, other than goodwill and identifiable intangible assets with indefinite lives, for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. An impairment loss is recognized when the sum of the undiscounted future cash flows is less than the carrying amount of the asset, in which case a write-down is recorded to reduce the related asset to its estimated fair value.
Workers’ Compensation and Medical Malpractice Loss Reserves	'
	Workers’ Compensation and Medical Malpractice Loss Reserves. The Company carries retention policies for its workers’ compensation liability and medical malpractice liability exposures. In connection with these programs, the Company pays a base premium plus actual losses incurred, not to exceed certain stop-loss limits. The Company is insured for losses above these limits, both per occurrence and in the aggregate. The workers' compensation and medical malpractice 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 and differences in estimates and actual payments for claims are recognized in the period that the estimates changed or the payments were made
Contingencies	'
	Contingencies. The Company records an estimated loss from a loss contingency when information available prior to issuance of its financial statements indicates it is probable that an asset has been impaired or a liability has been incurred at the date of the financial statements, and the amount of the loss can be reasonably estimated. Accounting for contingencies, such as legal settlements, workers’ compensation matters and medical malpractice insurance matters, requires the Company to use judgment.
Business Combinations	'
	Business Combinations. The purchase price of an acquisition is allocated to the underlying assets acquired and liabilities assumed based upon their estimated fair values at the date of acquisition. To the extent the purchase price exceeds the fair value of the net identifiable tangible and intangible assets acquired and liabilities assumed, such excess is allocated to goodwill. The Company determines the estimated fair values after review and consideration of relevant information including discounted cash flows, quoted market prices and estimates made by management. Accordingly, these can be affected by contract performance and other factors over time, which may cause final amounts to differ materially from original estimates. The Company adjusts the preliminary purchase price allocation, as necessary, up to one year after the acquisition closing date if it obtains more information regarding asset valuations and liabilities assumed.
	Goodwill acquired in business combinations is assigned to the reporting unit(s) expected to benefit from the combination as of the acquisition date. Acquisition related costs are recognized separately from the acquisition and are expensed as incurred.
Stock-based Compensation	'
	Stock-Based Compensation. The Company records compensation expense for restricted stock awards and restricted stock units based on the fair market value of the awards on the date of grant. Compensation expense for performance-based awards is measured based on the amount of shares ultimately expected to vest, estimated at each reporting date based on management’s expectations regarding the relevant performance criteria. The Company accounts for stock options granted and Employee Stock Purchase plan ("ESPP") shares based on an estimated fair market value using a Black-Scholes option valuation model. This methodology requires the use of subjective assumptions including expected stock price volatility and the estimated life of each award. The fair value of equity-based compensation awards less the estimated forfeitures is amortized over the vesting period of the award.
Concentration of Credit Risk	'
	Concentration of Credit Risk. Financial instruments that potentially subject the Company to credit risks consist primarily of cash, cash equivalents and trade receivables. The Company places its cash and cash equivalents in low risk investments with quality credit institutions and limits the amount of credit exposure with any single institution above FDIC insured limits. Concentration of credit risk with respect to accounts receivable is limited because of the large number of geographically dispersed customers, thus spreading the trade credit risk. The Company performs ongoing credit evaluations to identify risks and maintains an allowance to address these risks.
Fair Value of Financial Instruments	'
	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 Consolidated Balance Sheets at December 31, 2013 was $399.8 million. The fair value of the long-term debt was determined using the quoted price technique, based on Level 2 inputs including the yields of comparable companies with similar credit characteristics, was $400.2 million.
Derivatives Instruments	'
	Derivative Instruments. The Company utilizes derivative financial instruments to manage interest rate risk. The Company does not use derivative financial instruments for trading or speculative purposes, nor does it use leveraged financial instruments.
Advertising Costs	'
	Advertising Costs. Advertising costs, which are expensed as incurred, were $5.0 million in 2013, $4.6 million in 2012, and $2.6 million in 2011, and are included in selling, general and adminsitrative ("SG&A") expenses.

Acquisitions_Business_Combinat

Acquisitions Business Combinations (Policies)	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Acquisition [Policy Text Block]	'
	Assets and liabilities of the acquired companies were recorded at their estimated fair values at the dates of acquisition. The excess purchase price over the fair value of net tangible assets and identifiable intangible assets acquired has been allocated to goodwill. The fair value assigned to identifiable intangible assets was determined primarily by using a discounted cash flow method.

Fair_Value_Measurements_Fair_V

Fair Value Measurements Fair Value of Financial Instruments Policy (Policies)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments, Policy [Policy Text Block]	'
	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 Consolidated Balance Sheets at December 31, 2013 was $399.8 million. The fair value of the long-term debt was determined using the quoted price technique, based on Level 2 inputs including the yields of comparable companies with similar credit characteristics, was $400.2 million.

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2013
Property, Plant and Equipment [Abstract]	'
Schedule of Property and Equipment	'
	Property and equipment at December 31, 2013 and 2012 consisted of the following (in thousands):
		2013			2012
	Furniture, fixtures and equipment	$	8,409		$	6,891
	Computers and related equipment	12,155			6,918
	Computer software	37,800			32,871
	Leasehold improvements	6,059			5,417
	Work-in-progress	14,929			9,937
		79,352			62,034
	Less -- accumulated depreciation and amortization	(40,761		)	(35,172		)
		$	38,591		$	26,862

Acquisitions_Tables

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Schedule of Purchase Price Allocation	'
	The following tables summarize (in thousands) the purchase price allocations for the acquisitions of CyberCoders and Whitaker, which are subject to finalization during the measurement period, and Apex, HCP and Valesta:
		2013 Acquisitions								2012 Acquisition				2011 Acquisitions
		CyberCoders				Whitaker				Apex				HCP				Valesta
	Current assets	$	10,805			$	8,909			$	172,042			$	3,950			$	6,332
	Property and equipment	3,790				272				902				123				299
	Goodwill	70,527				7,452				264,590				14,398				17,911
	Identifiable intangible assets	36,450				9,760				251,555				1,784				5,679
	Other	915				568				494				13				26
	Total assets acquired	$	122,487			$	26,961			$	689,583			$	20,268			$	30,247
	Current liabilities	$	8,022			$	5,083			$	77,905			$	1,070			$	4,774
	Other	15,817				551				850				49				1,814
	Total liabilities assumed	23,839				5,634				78,755				1,119				6,588
	Total purchase price	$	98,648			$	21,327			$	610,828			$	19,149			$	23,659
Schedule of Intangible Assets Acquired as Part of Business Combinations	'
	The following table summarizes (in thousands) the allocation of the purchase price among the identifiable intangible assets for the acquisitions of CyberCoders and Whitaker, which are subject to finalization during the measurement period, and Apex, HCP and Valesta:
				Identifiable Intangible Asset Value
				2013 Acquisitions								2012 Acquisition				2011 Acquisitions
		Useful life		CyberCoders				Whitaker				Apex				HCP				Valesta
	Contractor relations	2 – 5 years		$	3,900			$	1,800			$	10,589			$	814			$	266
	Customer relations	2 – 10 years		750				5,900				92,147				950				2,395
	Non-compete agreements	2 – 7 years		800				60				2,076				20				440
	In-use software	6 years		18,900				—				—				—				—
	Trademarks	indefinite		12,100				2,000				146,743				—				2,578
				$	36,450			$	9,760			$	251,555			$	1,784			$	5,679
Schedule of Pro Forma Consolidated Results of Operations	'
	The pro forma financial information is not necessarily indicative of the operating results that would have occurred if the acquisition had been consummated as of the date indicated, nor are they necessarily indicative of future operating results.
		2013				2012				2011
		(unaudited)
	Revenues	$	1,717,337			$	1,494,542			$	1,234,468
	Income from continuing operations	$	59,598			$	52,538			$	22,676
	Net income	$	89,756			$	58,732			$	26,109
	Basic earnings per share:
	Income from continuing operations	$	1.11			$	1.01			$	0.44
	Net income	$	1.68			$	1.13			$	0.51
	Diluted earnings per share
	Income from continuing operations	$	1.09			$	0.99			$	0.44
	Net income	$	1.65			$	1.1			$	0.5
	Weighted average number of shares outstanding	53,481				52,103				51,180
	Weighted average number of shares and dilutive shares outstanding	54,555				53,190				52,062

Discontinued_Operations_Discon1

Discontinued Operations Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2013
Discontinued Operations [Abstract]	'
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	'
	. Discontinued Operations.
	On December 2, 2013, the Company completed the sale of its Allied Healthcare division for $28.7 million in cash and recognized a gain of $16.4 million, net of income taxes of $10.4 million. The Allied Healthcare division, previously included in the Healthcare segment, has been presented as discontinued operations in our Consolidated Statements of Operations for all periods presented.
	On February 12, 2013, the Company completed the sale of the Nurse Travel division for $33.7 million in cash and recognized a gain of $14.4 million, net of income taxes of $9.1 million. The Nurse Travel division, previously included in the Healthcare segment, has been presented as discontinued operations in our Consolidated Statements of Operations for all periods presented.
	The following is a summary of Allied Healthcare's and Nurse Travel's combined operating results for each of the years in the period ended December 31, 2013 (in thousands):
		2013			2012		2011
	Revenues	$	44,569		$	101,719	$	81,697
	Income (loss) before income taxes	$	(967	)	$	10,356	$	5,766
	Provision for income taxes	$	(284	)	$	4,162	$	2,333
	Net income (loss)	$	(683	)	$	6,194	$	3,433
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	'
	The following is a summary of Allied Healthcare's and Nurse Travel's combined operating results for each of the years in the period ended December 31, 2013 (in thousands):
		2013			2012		2011
	Revenues	$	44,569		$	101,719	$	81,697
	Income (loss) before income taxes	$	(967	)	$	10,356	$	5,766
	Provision for income taxes	$	(284	)	$	4,162	$	2,333
	Net income (loss)	$	(683	)	$	6,194	$	3,433

LongTerm_Debt_Tables

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Disclosure [Abstract]	'
Contractual Obligation, Fiscal Year Maturity Schedule [Table Text Block]	'
	During the remainder of this fiscal year, each of the next four years and thereafter, the Company will be required to make payments as follows (in thousands):
	2014		$	10,000
	2015		10,000
	2016		10,000
	2017		10,875
	2018		99,750
	Thereafter		259,188
	Total		$	399,813
	The following is a summary of specified contractual cash obligation payments by the Company, including discontinued operations, as of December 31, 2013 (in thousands):
			Operating Leases			Related Party Leases		Total
	2014		$	15,685		$	1,299	$	16,984
	2015		13,863			1,168		15,031
	2016		11,236			694		11,930
	2017		7,523			175		7,698
	2018		5,351			—		5,351
	Thereafter		8,699			—		8,699
	Total		$	62,357		$	3,336	$	65,693
Schedule of Long-term Debt	'
	Long-term debt consisted of the following (in thousands):
		2013			2012
	Senior Secured Debt
	$125 million revolving credit facility, due May 2018	$	44,500		$	—
	$100 million term A loan facility, due May 2018	92,500			—
	$275 million term B loan facility, due May 2020	262,813			—
	$75 million revolving credit facility	—			—
	$100 million term A loan facility, repaid May 2013	—			92,500
	$365 million term B loan facility, repaid May 2013	—			334,088
		$	399,813		$	426,588

Goodwill_and_Identifiable_Asse1

Goodwill and Identifiable Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Schedule of Goodwill	'
	The changes in the carrying amount of goodwill for the years ended December 31, 2013 and 2012 are as follows (in thousands):
		Apex			Oxford			Life Sciences			Healthcare				Physician				Total
	Balance as of December 31, 2011
	Gross goodwill	$	—		$	149,483		$	27,668		$	122,230			$	51,570			$	350,951
	Accumulated impairment loss	—			—			—			(121,717		)		—				(121,717		)
		—			149,483			27,668			513				51,570				229,234
	Apex Acquisition (see Note 3)	264,590			—			—			—				—				264,590
	Acquisition Accounting	—			—			1,814			—				(9		)		1,805
	Translation adjustment	—			—			529			—				—				529
	Balance as of December 31, 2012
	Gross goodwill	264,590			149,483			30,011			122,230				51,561				617,875
	Accumulated impairment loss	—			—			—			(121,717		)		—				(121,717		)
		264,590			149,483			30,011			513				51,561				496,158
	Whitaker acquisition (see Note 3)	—			—			—			—				7,452				7,452
	CyberCoders acquisition (see Note 3)	—			70,527			—			—				—				70,527
	Divestiture - gross goodwill	—			—			—			(121,717		)		—				(121,717		)
	Divestiture - accumulated impairment loss	—			—			—			121,717				—				121,717
	Transfers	—			513			—			(513		)		—				—
	Translation adjustment	—			—			811			—				—				811
	Balance as of December 31, 2013
	Gross goodwill	264,590			220,523			30,822			—				59,013				574,948
	Accumulated impairment	—			—			—			—				—				—
		$	264,590		$	220,523		$	30,822		$	—			$	59,013			$	574,948
Schedule of Acquired Intangible Assets	'
	As of December 31, 2013 and December 31, 2012, the Company had the following acquired intangible assets (in thousands):
				2013										2012
			Estimated Useful Life	Gross Carrying Amount			Accumulated Amortization			Net Carrying Amount				Gross Carrying Amount				Accumulated Amortization				Net Carrying Amount
	Subject to amortization:
	Customer relations		3 months – 10 years	$	110,007		$	41,564		$	68,443			$	103,285			$	23,338			$	79,947
	Contractor relations		2 - 7 years	43,598			30,737			12,861				37,871				27,754				10,117
	Non-compete agreements		2 - 7 years	3,863			1,424			2,439				2,986				1,062				1,924
	In-use software		6 years	18,900			263			18,637				—				—				—
				176,368			73,988			102,380				144,142				52,154				91,988
	Not subject to amortization:
	Trademarks			186,075			—			186,075				171,852				—				171,852
	Goodwill			574,948			—			574,948				496,158				—				496,158
	Total			$	937,391		$	73,988		$	863,403			$	812,152			$	52,154			$	759,998
Schedule of Estimated Future Amortization Expense	'
	Estimated amortization for the each of the next five fiscal years and thereafter follows (in thousands):
	2014	$	24,509
	2015	21,326
	2016	17,721
	2017	12,888
	2018	10,307
	Thereafter	15,629
		$	102,380

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Schedule of Contractual Cash Obligation Payments	'
	During the remainder of this fiscal year, each of the next four years and thereafter, the Company will be required to make payments as follows (in thousands):
	2014	$	10,000
	2015	10,000
	2016	10,000
	2017	10,875
	2018	99,750
	Thereafter	259,188
	Total	$	399,813
	The following is a summary of specified contractual cash obligation payments by the Company, including discontinued operations, as of December 31, 2013 (in thousands):
		Operating Leases		Related Party Leases		Total
	2014	$	15,685	$	1,299	$	16,984
	2015	13,863		1,168		15,031
	2016	11,236		694		11,930
	2017	7,523		175		7,698
	2018	5,351		—		5,351
	Thereafter	8,699		—		8,699
	Total	$	62,357	$	3,336	$	65,693

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Schedule of Components of Income Taxes	'
	The provision (benefit) for income taxes consists of the following (in thousands):
		Year Ended December 31,
		2013			2012			2011
	Current:
	Federal	$	28,142		$	17,083		$	7,723
	State	5,266			2,742			1,223
	Foreign	1,223			2,645			1,465
		34,631			22,470			10,411
	Deferred:
	Federal & State	4,245			6,235			4,354
	Foreign	(84		)	(564		)	68
		4,161			5,671			4,422
		$	38,792		$	28,141		$	14,833
Income (Loss) before Income Tax Provision	'
	Income from continuing operations before income taxes consists of the following (in thousands):
		Year Ended December 31,
		2013			2012			2011
	United States	$	88,637		$	61,828		$	31,639
	Foreign	4,510			2,772			4,058
		$	93,147		$	64,600		$	35,697
Schedule of Deferred Tax Assets and Liabilities	'
	The components of deferred tax assets (liabilities) are as follows (in thousands):
		December 31,			December 31,
		2013			2012
	Deferred income tax assets (liabilities):
	Current:
	Allowance for doubtful accounts	$	1,578		$	1,150
	Employee related accruals	6,663			3,419
	State taxes	611			1,064
	Workers’ compensation and medical malpractice loss reserves	4,767			4,683
	Other	3,595			(169		)
		17,214			10,147
	Non-current:
	Intangibles	(49,122		)	(23,662		)
	Depreciation expense	(6,147		)	(4,449		)
	Stock-based compensation	3,761			2,852
	Net operating loss carryforwards	1,612			1,191
	Other	1,822			1,975
		(48,074		)	(22,093		)
	Valuation allowance	(1,511		)	(916		)
	Total net deferred income tax liability	$	(32,371	)	$	(12,862	)
Schedule of Effective Income Tax Rate Reconciliation	'
	The reconciliation between the amount computed by applying the U.S. federal statutory tax rate of 35.0 percent to income before income taxes and the income tax provision is as follows (in thousands):
		Year Ended December 31,
		2013			2012			2011
	Income tax provision at the statutory rate	$	32,602		$	22,610		$	12,494
	State income taxes, net of federal benefit	4,039			2,555			1,283
	Disallowed meals and entertainment expenses	1,592			1,681			1,020
	Other	559			1,295			36
		$	38,792		$	28,141		$	14,833
Schedule of Unrecognized Tax Benefits Roll Forward	'
	The following is a reconciliation of the total amounts of unrecognized tax benefits (in thousands):
		Year Ended December 31,
		2013			2012			2011
	Unrecognized Tax Benefit beginning of year	$	376		$	251		$	358
	Gross increases - tax positions in prior year	1,240			159			—
	Gross decreases - tax positions in prior year	(177		)	(34		)	—
	Lapse of the statute of limitations	—			—			(107		)
	Unrecognized Tax Benefit end of year	$	1,439		$	376		$	251

Earnings_per_share_Tables

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2013
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):
		Year Ended December 31,
		2013	2012	2011
	Weighted average number of common shares	53,481	46,739	36,876
	Dilutive effect of stock-based awards	1,074	1,087	882
	Number of shares used to compute diluted earnings per share	54,555	47,826	37,758
Schedule of Weighted Average Share Equivalents Outstanding Excluded from Computation of Diluted Earnings per Share	'
	Also excluded from the computation of diluted earnings per share were other share equivalents that became anti-dilutive when applying the treasury stock method.
		Year Ended December 31,
		2013	2012	2011
	Anti-dilutive common share equivalents outstanding	7	83	1,039

Stockbased_Compensation_Incent1

Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	'
	The following table displays the weighted average assumptions that have been applied to estimate the fair value of stock option awards on the date of grant. During 2013, the Company did not grant any stock option awards.
			Year Ended December 31,
			2012			2011
	Dividend yield		—			—
	Risk-free interest rate		1.19	%		0.92	%
	Expected volatility		64.15	%		75.67	%
	Expected lives		7.3 years			3.6 years
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]	'
	The following summarizes pricing and term information for options outstanding as of December 31, 2013:
									Options Outstanding							Options Exercisable
									Number Outstanding at		Weighted Average Remaining Contractual Life (years)		Weighted Average Exercise Price			Number Exercisable at	Weighted Average Exercise Price
	Range of Exercise Prices								31-Dec-13							31-Dec-13
	$	4.44			─		$	8.26	255,250		4.8			$	6.62	214,351		$	6.34
	8.38				─		11.39		272,121		5.1			10.9		196,831		11.08
	11.56				─		12.9		213,724		3.1			12.39		213,724		12.39
	13.31				─		13.58		43,850		3.3			13.32		43,006		13.31
	16.51				─		16.51		75,000		8.7			16.51		23,437		16.51
	$	4.44			─		$	16.51	859,945		4.8			$	10.61	691,349		$	10.34
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]	'
	The following table is a summary of stock option activity under the Plan as of December 31, 2013 and changes for the year then ended:
			Incentive Stock Options		Non- Qualified Stock Options		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual			Aggregate Intrinsic Value
									Term (Years)
	Outstanding at January 1, 2013		129,423		1,156,937		$	9.83		5.6		$	13,442,000
	Exercised		-59,806		-333,377		$	8.13
	Canceled		-201		-33,031		$	9.65
	Outstanding at December 31, 2013		69,416		790,529		$	10.61		4.8		$	20,903,000
	Vested and Expected to Vest at December 31, 2013		69,416		772,942		$	10.56		4.7		$	20,521,000
	Exercisable at December 31, 2013		69,386		621,963		$	10.34		4		$	16,995,000
Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]	'
	Restricted Stock Units and Restricted Stock Awards
	A summary of the status of the Company’s unvested RSUs as of December 31, 2013 and changes during the year then ended are presented below:
			Restricted Stock Units / Awards			Weighted Average Grant-Date Fair Value Per Unit / Award
	Unvested RSUs outstanding at January 1, 2013		1,390,834				$	14.31
	Granted		621,262				26.77
	Market value share count adjustment for liability awards		(55,664	)			34.92
	Vested		(538,525	)			14.76
	Forfeited		(50,669	)			15.75
	Unvested RSUs outstanding at December 31, 2013		1,367,238				$	18.9
	Unvested and expected to vest RSUs outstanding at December 31, 2013		1,201,190				$	19.12

Business_Segments_Tables

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Schedule of Segment Reporting Information, by Segment	'
	The following table represents revenues, gross profit, operating income, amortization and total assets by reportable segment (in thousands):
		Year ended December 31, 2013
		Apex			Oxford			Life Sciences				Physician		Corporate			Total
	Revenues	$	942,463		$	412,189		$	171,518			$	105,827	$	—		$	1,631,997
	Gross Profit	258,150			143,334			56,308				30,614		—			488,406
	Operating income	76,971			58,990			28,354				8,852		(49,199		)	123,968
	Amortization	19,524			965			429				742		91			21,751
	Total assets (1)	656,733			365,118			128,824				110,519		—			1,261,194
		Year ended December 31, 2012
		Apex			Oxford			Life Sciences				Physician		Corporate			Total
	Revenues	$	508,743		$	363,765		$	162,799			$	102,679	$	—		$	1,137,986
	Gross Profit	140,669			127,895			55,874				31,455		—			355,893
	Operating income	36,416			56,289			25,632				9,998		(47,154		)	81,181
	Amortization	15,665			437			807				817		290			18,016
	Total assets (1)	642,594			235,099			150,696			(2)	86,074		—			1,114,463
		Year ended December 31, 2011
		Apex			Oxford			Life Sciences				Physician		Corporate			Total
	Revenues	$	—		$	279,643		$	155,324			$	80,617	$	—		$	515,584
	Gross Profit	—			99,187			52,643				25,858		—			177,688
	Operating income	—			37,676			24,883				6,699		(30,625		)	38,633
	Amortization	—			821			901				415		209			2,346
	Total assets (1)	—			221,690			119,563			(2)	86,014		—			427,267
	______
	(1) As of end of the year.
	(2) Life Sciences total assets as of December 31, 2012 and 2011 include assets related to the Healthcare segment, which were sold and included in discontinued operations in 2013. Historically, the Company has not reported Life Science and Healthcare segments' total assets separately as the operations were largely centralized.
Schedule of Revenue by Geographical Areas	'The Company operates internationally, with operations in the United States, Europe, Canada, China, Australia, and New Zealand. The following table represents revenues by geographic location (in thousands):  Year Ended December 31,  2013 2012 2011Revenues:      Domestic $1,552,322 $1,060,217 $447,453Foreign 79,675 77,769 68,131  $1,631,997 $1,137,986 $515,584
Long Lived Assets By Geographic Location Domestic And Foreign	'
	The following table represents long-lived assets by geographic location (in thousands):
			December 31,
			2013			2012			2011
	Long-lived Assets:
	Domestic		$	45,061		$	40,062		$	19,078
	Foreign		2,856			2,006			1,033
			$	47,917		$	42,068		$	20,111

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	'
	The assets and liabilities measured at fair value on a recurring basis are as follows (in thousands):
		As of December 31, 2013
		Fair Value Measurements Using									Total
		Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs
		(Level 1)			(Level 2)			(Level 3)
	Contingent consideration to be paid in cash for the acquisitions	$	—		$	—		$	(8,527	)	$	(8,527	)
		As of December 31, 2012
		Fair Value Measurements Using									Total
		Quoted Prices in Active Markets for Identical Assets			Significant Other Observable Inputs			Significant Unobservable Inputs
		(Level 1)			(Level 2)			(Level 3)
	Contingent consideration to be paid in cash for the acquisitions	$	—		$	—		$	(7,577	)	$	(7,577	)
Schedule of Reconciliations of Liabilities Measured and Carried at Fair Value on Recurring Basis, with Significant Unobservable Inputs	'
	Reconciliations of liabilities measured and carried at fair value on a recurring basis with the use of significant unobservable inputs (Level 3) are as follows (in thousands):
		Year Ended December 31,
		2013			2012
	Contingent consideration for acquisitions --
	Balance at beginning of year	$	(7,577	)	$	(9,856	)
	Additions for acquisitions	(7,860		)	—
	Payments on contingent consideration	3,425			1,198
	Settlements of contingent consideration	—			—
	Fair value adjustments	3,584			1,215
	Foreign currency translation adjustment	(99		)	(134		)
	Balance at end of year	$	(8,527	)	$	(7,577	)

Unaudited_Quarterly_Financial_1

Unaudited Quarterly Financial Results (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Unaudited Quarterly Financial Information	'
		2013
		Dec. 31,		Sep. 30,		June 30,		Mar. 31,
		(in thousands, except per share data)
	Revenues	$	423,598	$	421,491	$	407,864	$	379,044
	Gross profit	$	129,753	$	127,210	$	121,332	$	110,111
	Income from continuing operations	$	17,425	$	19,471	$	7,243	$	10,216
	Income from discontinued operations, net of income taxes	14,985		679		96		14,397
	Net income	$	32,410	$	20,150	$	7,339	$	24,613
	Basic earnings per common share:
	Income from continuing operations	$	0.32	$	0.36	$	0.14	$	0.19
	Income from discontinued operations	0.28		0.02		—		0.27
	Net income	$	0.6	$	0.38	$	0.14	$	0.46
	Diluted earnings per common share:
	Income from continuing operations	$	0.32	$	0.36	$	0.13	$	0.19
	Income from discontinued operations	0.27		0.01		0.01		0.27
	Net income	$	0.59	$	0.37	$	0.14	$	0.46
		2012
		Dec. 31,		Sep. 30,		June 30,		Mar. 31,
		(in thousands, except per share data)
	Revenues	$	369,441	$	363,882	$	256,386	$	148,277
	Gross profit	$	112,054	$	112,213	$	81,509	$	50,117
	Income from continuing operations	$	12,004	$	14,078	$	5,586	$	4,791
	Income from discontinued operations, net of income taxes	2,201		1,425		1,976		592
	Net income	$	14,205	$	15,503	$	7,562	$	5,383
	Basic earnings per common share:
	Income from continuing operations	$	0.23	$	0.27	$	0.12	$	0.13
	Income from discontinued operations	0.04		0.03		0.05		0.01
	Net income	$	0.27	$	0.3	$	0.17	$	0.14
	Diluted earnings per common share:
	Income from continuing operations	$	0.22	$	0.26	$	0.12	$	0.13
	Income from discontinued operations	0.04		0.03		0.04		0.01
	Net income	$	0.26	$	0.29	$	0.16	$	0.14

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'
Workers’ compensation and medical malpractice receivable	$21,200,000	$16,442,000	'
Goodwill	574,948,000	496,158,000	229,234,000
Long-term Debt	399,813,000	'	'
Advertising costs	5,000,000	4,600,000	2,600,000
Document Fiscal Year Focus	'2013	'	'
Fair Value, Inputs, Level 2	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'
Long-term debt, fair value	$400,200,000	'	'

Summary_of_Significant_Account3

Summary of Significant Accounting Policies Workers compensation and medical malpractice reclassification (Details) (USD $)	0 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2012
Accounting Changes and Error Corrections [Abstract]	'
Prior Period Reclassification Adjustment	$16,400

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]	'	'
Document Fiscal Year Focus	'2013	'
Property and equipment	$79,352	$62,034
Less -- accumulated depreciation and amortization	40,761	35,172
Total	38,591	26,862
Furniture, fixtures and equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment	8,409	6,891
Computer and related equipment [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment	12,155	6,918
Software [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment	37,800	32,871
Leasehold improvements [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment	6,059	5,417
Work-in-progress [Member]	'	'
Property, Plant and Equipment [Line Items]	'	'
Property and equipment	$14,929	$9,937

Property_and_Equipment_Narrati

Property and Equipment (Narratives) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]	'	'	'
Net book value	$38,591,000	$26,862,000	'
Depreciation	8,000,000	6,500,000	5,300,000
Document Fiscal Year Focus	'2013	'	'
Software Development	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Net book value	13,500,000	12,100,000	'
Software Development Work-in-Progress	'	'	'
Property, Plant and Equipment [Line Items]	'	'	'
Net book value	$10,000,000	$7,500,000	'

Acquisitions_Schedule_of_Purch

Acquisitions (Schedule of Purchase Price Allocation) (Details)

12 Months Ended

1 Months Ended

12 Months Ended

1 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 05, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 02, 2013

15-May-12

Dec. 31, 2012

Sep. 30, 2012

Jul. 31, 2011

Dec. 31, 2011

Feb. 28, 2011

Feb. 28, 2011

Dec. 31, 2011

Dec. 05, 2013

Dec. 02, 2013

15-May-12

Jul. 31, 2011

Feb. 28, 2011

Dec. 05, 2013

Dec. 02, 2013

15-May-12

Jul. 31, 2011

Feb. 28, 2011

Dec. 05, 2013

Dec. 02, 2013

15-May-12

Jul. 31, 2011

Feb. 28, 2011

Dec. 05, 2013

Dec. 05, 2013

Dec. 02, 2013

15-May-12

Jul. 31, 2011

Feb. 28, 2011

USD ($)

USD ($)

CyberCoders [Member]

CyberCoders [Member]

CyberCoders [Member]

Whitaker [Member]

Whitaker [Member]

Whitaker [Member]

Apex Systems

Apex Systems

Apex Systems

HCP

HCP

Valesta

Valesta

Valesta

Contractor Relations [Member]

Contractor Relations [Member]

Contractor Relations [Member]

Contractor Relations [Member]

Contractor Relations [Member]

Customer Relationships [Member]

Customer Relationships [Member]

Customer Relationships [Member]

Customer Relationships [Member]

Customer Relationships [Member]

Noncompete Agreements [Member]

Noncompete Agreements [Member]

Noncompete Agreements [Member]

Noncompete Agreements [Member]

Noncompete Agreements [Member]

Software [Member]

Trademarks [Member]

Trademarks [Member]

Trademarks [Member]

Trademarks [Member]

Trademarks [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

EUR (€)

USD ($)

CyberCoders [Member]

Whitaker [Member]

Apex Systems

HCP

Valesta

CyberCoders [Member]

Whitaker [Member]

Apex Systems

HCP

Valesta

CyberCoders [Member]

Whitaker [Member]

Apex Systems

HCP

Valesta

CyberCoders [Member]

CyberCoders [Member]

Whitaker [Member]

Apex Systems

HCP

Valesta

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquired Finite-lived Intangible Asset, Amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$3,900,000

$1,800,000

$10,589,000

$814,000

$266,000

$750,000

$5,900,000

$92,147,000

$950,000

$2,395,000

$800,000

$60,000

$2,076,000

$20,000

$440,000

$18,900,000

'

'

'

'

'

Acquired Indefinite-lived Intangible Asset, Amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12,100,000

2,000,000

146,743,000

0

2,578,000

Business Acquisition, Effective Date of Acquisition

'

'

5-Dec-13

'

'

2-Dec-13

'

'

15-May-12

'

'

31-Jul-11

'

28-Feb-11

28-Feb-11

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Name of Acquired Entity

'

'

'CyberCoders Holdings, Inc

'

'

'Whitaker Medical, LLC

'

'

'Apex Systems, Inc.

'

'

'HealthCare Partners, Inc. ("HCP")

'

'Warphi N.V. and its subsidiaries (collectively, "Valesta")

'Warphi N.V. and its subsidiaries (collectively, "Valesta")

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Description of Acquired Entity

'

'

' a privately-owned provider of permanent placement services headquartered in Irvine, California.

'

'

'a privately-owned provider of physician staffing services headquartered in Houston, Texas.

'

'

'a privately-owned provider of information technology staffing headquartered in Richmond, Virginia.

'

'

'a privately-owned provider of physician staffing headquartered in Atlanta, Georgia

'

'a privately-owned provider of specialized clinical research staffing headquartered in Belgium

'a privately-owned provider of specialized clinical research staffing headquartered in Belgium

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Reason for Business Combination

'

'

'The primary reason for the acquisition was to expand the Company's permanent placement services.

'

'

'The primary reason for the acquisition was to expand the Company's Physician staffing services.

'

'

'The primary reason for the acquisition was to expand the Company's information technology staffing services.

'

'

'The primary reasons for the acquisition were to expand the Physician segment business operations geographic coverage and to leverage the Company’s infrastructure.

'

'The primary reasons for the acquisition were to expand the Life Sciences business operations and to leverage the Company’s infrastructure

'The primary reasons for the acquisition were to expand the Life Sciences business operations and to leverage the Company’s infrastructure

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Consideration Transferred

'

'

'

'

98,600,000

'

'

21,300,000

610,800,000

'

'

19,100,000

'

23,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Current assets

'

'

'

'

10,805,000

'

'

8,909,000

172,042,000

'

'

3,950,000

'

6,332,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property and equipment

'

'

'

'

3,790,000

'

'

272,000

902,000

'

'

123,000

'

299,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill, Acquired During Period

264,590,000

'

'

70,527,000

'

'

7,452,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill

'

'

'

'

70,527,000

'

'

7,452,000

264,590,000

'

'

14,398,000

'

17,911,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Identifiable intangible assets

'

'

'

'

36,450,000

'

'

9,760,000

251,555,000

'

'

1,784,000

'

5,679,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other

'

'

'

'

915,000

'

'

568,000

494,000

'

'

13,000

'

26,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total assets acquired

'

'

'

'

122,487,000

'

'

26,961,000

689,583,000

'

'

20,268,000

'

30,247,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Current liabilities

'

'

'

'

8,022,000

'

'

5,083,000

77,905,000

'

'

1,070,000

'

4,774,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Other

'

'

'

'

15,817,000

'

'

551,000

850,000

'

'

49,000

'

1,814,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total liabilities assumed

'

'

'

'

23,839,000

'

'

5,634,000

78,755,000

'

'

1,119,000

'

6,588,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total purchase price

'

'

'

'

98,648,000

'

'

21,327,000

610,828,000

'

'

19,149,000

'

23,659,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Cost of Acquired Entity, Cash Paid

'

'

'

'

93,600,000

'

'

18,500,000

385,000,000

'

300,000

15,700,000

'

16,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Contingent Consideration, at Fair Value

'

'

'

'

5,000,000

'

'

2,800,000

'

'

'

3,400,000

'

6,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Contingent Consideration, Potential Cash Payment

'

16,000,000

'

'

11,000,000

'

'

5,000,000

'

'

'

3,700,000

'

'

5,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Acquisition Related Costs

'

'

'

1,500,000

'

'

400,000

'

'

9,800,000

'

'

57,000

'

'

400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition, Purchase Price Allocation, Goodwill, Expected Tax Deductible Amount

'

'

'

'

10,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual

'

'

3,600,000

'

'

2,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual

'

'

($100,000)

'

'

($28,000)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquisitions_Schedule_of_Intan

Acquisitions (Schedule of Intangible Assets Acquired as Part of Business Combination) (Details) (USD $)

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 05, 2013

Dec. 05, 2013

Dec. 05, 2013

Dec. 05, 2013

Dec. 05, 2013

Dec. 05, 2013

Dec. 02, 2013

Dec. 02, 2013

Dec. 02, 2013

Dec. 02, 2013

Dec. 02, 2013

15-May-12

15-May-12

15-May-12

15-May-12

15-May-12

Jul. 31, 2011

Jul. 31, 2011

Jul. 31, 2011

Jul. 31, 2011

Jul. 31, 2011

Feb. 28, 2011

Feb. 28, 2011

Feb. 28, 2011

Feb. 28, 2011

Feb. 28, 2011

Contractor relations

Contractor relations

Customer Relationships [Member]

Customer Relationships [Member]

Non-compete agreements

Non-compete agreements

Software [Member]

CyberCoders [Member]

CyberCoders [Member]

CyberCoders [Member]

CyberCoders [Member]

CyberCoders [Member]

CyberCoders [Member]

Whitaker [Member]

Whitaker [Member]

Whitaker [Member]

Whitaker [Member]

Whitaker [Member]

Apex Systems

Apex Systems

Apex Systems

Apex Systems

Apex Systems

HCP

HCP

HCP

HCP

HCP

Valesta

Valesta

Valesta

Valesta

Valesta

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Trademarks [Member]

Contractor relations

Customer Relationships [Member]

Non-compete agreements

Software [Member]

Trademarks [Member]

Contractor relations

Customer Relationships [Member]

Non-compete agreements

Trademarks [Member]

Contractor relations

Customer Relationships [Member]

Non-compete agreements

Trademarks [Member]

Contractor relations

Customer Relationships [Member]

Non-compete agreements

Trademarks [Member]

Contractor relations

Customer Relationships [Member]

Non-compete agreements

Acquired Intangible Assets [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Finite lived, Intangible asset value

'

'

'

'

'

'

'

'

'

$3,900

$750

$800

$18,900

'

'

$1,800

$5,900

$60

'

'

$10,589

$92,147

$2,076

'

'

$814

$950

$20

'

'

$266

$2,395

$440

Useful life

'5 years

'2 years

'10 years

'2 years

'7 years

'2 years

'6 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquired Indefinite-lived Intangible Asset, Amount

'

'

'

'

'

'

'

'

12,100

'

'

'

'

'

2,000

'

'

'

'

146,743

'

'

'

'

0

'

'

'

'

2,578

'

'

'

Total intangible assets acquired

'

'

'

'

'

'

'

$36,450

'

'

'

'

'

$9,760

'

'

'

'

$251,555

'

'

'

'

$1,784

'

'

'

'

$5,679

'

'

'

'

Acquisitions_Acquisitions_Cost

Acquisitions (Acquisitions Costs, by Acquisition) (Details)

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 05, 2013

15-May-12

Dec. 31, 2012

Sep. 30, 2012

Jul. 31, 2011

Dec. 31, 2011

Feb. 28, 2011

Feb. 28, 2011

Dec. 31, 2011

Share data in Millions, unless otherwise specified

USD ($)

CyberCoders [Member]

CyberCoders [Member]

CyberCoders [Member]

Apex Systems

Apex Systems

Apex Systems

HCP

HCP

Valesta

Valesta

Valesta

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

EUR (€)

USD ($)

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Effective Date of Acquisition

'

5-Dec-13

'

'

15-May-12

'

'

31-Jul-11

'

28-Feb-11

28-Feb-11

'

Name of Acquired Entity

'

'CyberCoders Holdings, Inc

'

'

'Apex Systems, Inc.

'

'

'HealthCare Partners, Inc. ("HCP")

'

'Warphi N.V. and its subsidiaries (collectively, "Valesta")

'Warphi N.V. and its subsidiaries (collectively, "Valesta")

'

Description of Acquired Entity

'

' a privately-owned provider of permanent placement services headquartered in Irvine, California.

'

'

'a privately-owned provider of information technology staffing headquartered in Richmond, Virginia.

'

'

'a privately-owned provider of physician staffing headquartered in Atlanta, Georgia

'

'a privately-owned provider of specialized clinical research staffing headquartered in Belgium

'a privately-owned provider of specialized clinical research staffing headquartered in Belgium

'

Reason for Business Combination

'

'The primary reason for the acquisition was to expand the Company's permanent placement services.

'

'

'The primary reason for the acquisition was to expand the Company's information technology staffing services.

'

'

'The primary reasons for the acquisition were to expand the Physician segment business operations geographic coverage and to leverage the Company’s infrastructure.

'

'The primary reasons for the acquisition were to expand the Life Sciences business operations and to leverage the Company’s infrastructure

'The primary reasons for the acquisition were to expand the Life Sciences business operations and to leverage the Company’s infrastructure

'

Purchase price

'

'

'

$98,600,000

$610,800,000

'

'

$19,100,000

'

$23,700,000

'

'

Cost of acquired entity, cash paid

'

'

'

93,600,000

385,000,000

'

300,000

15,700,000

'

16,800,000

'

'

Shares of Company's common stock issued (in shares)

'

'

'

'

14.3

'

'

'

'

'

'

'

Business Combination, Acquisition Related Costs

'

'

1,500,000

'

'

9,800,000

'

'

57,000

'

'

400,000

Revenues of acquiree included in statement of operations

'

3,600,000

'

'

'

'

'

'

'

'

'

'

Net loss of acquiree included in statement of operations

'

-100,000

'

'

'

'

'

'

'

'

'

'

Potential future earn-out consideration

'

'

'

5,000,000

'

'

'

3,400,000

'

6,900,000

'

'

Maximum earn-out capped

$16,000,000

'

'

$11,000,000

'

'

'

$3,700,000

'

'

€ 5,000,000

'

Acquisitions_Business_Acquisit

Acquisitions (Business Acquisition, Pro Forma Information) (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Business Acquisition, Pro Forma Information [Abstract]	'	'	'
Revenues	$1,717,337	$1,494,542	$1,234,468
Operating income	59,598	52,538	22,676
Net income	$89,756	$58,732	$26,109
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Basic	$1.11	$1.01	$0.44
Basic earnings per share (in dollars per share)	$1.68	$1.13	$0.51
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Changes in Accounting and Extraordinary Items, Net of Tax, Per Share, Diluted	$1.09	$0.99	$0.44
Diluted earnings per share (in dollars per share)	$1.65	$1.10	$0.50
Weighted average number of shares outstanding	53,481	52,103	51,180
Weighted average number of shares and dilutive shares outstanding	54,555	53,190	52,062

Discontinued_Operations_Discon2

Discontinued Operations Discontinued Operations (Details) (USD $)

0 Months Ended

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 02, 2013

Feb. 12, 2013

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Discontinued Operations and Disposal Groups [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from Divestiture of Businesses

$28,700

$33,700

'

'

'

'

'

'

'

'

$59,899

'

'

Gain on sale of discontinued operations, net of income taxes

16,400

14,400

'

'

'

'

'

'

'

'

30,840

0

0

Disposal Group, Including Discontinued Operation, Revenue

'

'

'

'

'

'

'

'

'

'

44,569

101,719

81,697

Disposal Group, Including Discontinued Operation, Operating Income (Loss)

'

'

'

'

'

'

'

'

'

'

-967

10,356

5,766

Discontinued Operation, Tax Effect of Discontinued Operation

10,400

9,100

'

'

'

'

'

'

'

'

-284

4,162

2,333

Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent

'

'

$14,985

$679

$96

$14,397

$2,201

$1,425

$1,976

$592

($683)

$6,194

$3,433

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)

0 Months Ended

12 Months Ended

0 Months Ended

0 Months Ended

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

16-May-13

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2012

16-May-13

16-May-13

16-May-13

Dec. 31, 2013

16-May-13

Dec. 31, 2013

Sep. 30, 2013

16-May-13

Dec. 31, 2013

Dec. 31, 2013

16-May-13

16-May-13

16-May-13

Dec. 31, 2013

Dec. 31, 2013

Maximum [Member]

Term A Loans, Term B Loans and Revolving Loans [Member]

Term Loan Facility

Term Loan Facility

Term Loan Facility

Term Loan Facility

Term Loan Facility

Term Loan Facility

Term Loan Facility

Term Loan Facility

Term Loan Facility

Term Loan Facility

Term Loan Facility

Revolving Credit Facility

Revolving Credit Facility

Revolving Credit Facility

Revolving Credit Facility

Revolving Credit Facility

Revolving Credit Facility

Revolving Credit Facility

$100 million term A loan facility, due May 2017

$100 million term A loan facility, due May 2017

$365 million term B loan facility, due May 2019

Revolving Loans and Term A Loans

Revolving Loans and Term A Loans

Term A Loans, Term B Loans and Revolving Loans [Member]

Term-A Loan Facility due May 2018 [Member]

Term-A Loan Facility due May 2018 [Member]

Term-B Loan Facility due May 2020 [Member]

Term-B Loan Facility due May 2020 [Member]

Term-B Loan Facility due May 2020 [Member]

Revolving Credit Facility due May 2018 [Member]

Revolving Credit Facility due May 2018 [Member]

Revolving Credit Facility due May 2018 [Member]

Revolving Credit Facility due May 2018 [Member]

Revolving Credit Facility due May 2018 [Member]

Revolving Credit Facility due May 2018 [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Base Rate [Member]

Spread [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months

$10,000,000

$10,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Document Period End Date

'

31-Dec-13

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Senior Secured Debt

399,813,000

399,813,000

426,588,000

'

'

'

'

92,500,000

334,088,000

'

'

'

92,500,000

'

262,813,000

'

'

'

44,500,000

'

'

'

'

'

Face amount of term loan

'

'

'

'

'

'

'

'

'

'

'

'

'

100,000,000

'

'

275,000,000

'

'

'

'

'

'

'

Line of credit facility, maximum borrowing capacity

'

'

'

'

'

500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

125,000,000

'

'

'

'

Increase to borrowing capacity available under credit facility

'

'

'

'

'

'

'

'

'

'

'

100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Write off of Deferred Debt Issuance Cost

'

14,958,000

813,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Basis spread on variable rate borrowings

'

'

'

'

'

'

'

'

'

2.50%

1.75%

'

'

'

'

'

2.50%

'

'

'

'

'

'

'

Debt Instrument, Interest Rate, Stated Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.00%

'

'

'

'

'

'

'

Revolving credit facility, unused portion, commitment fee percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.40%

0.25%

'

'

Pledged equity interest in foreign subsidiaries

65.00%

65.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Leverage Ratio in Latest Year of Debt Term

'

'

'

'

3.25

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate at year end

'

'

'

'

'

'

2.20%

'

'

'

'

'

'

'

'

3.50%

'

'

'

'

'

'

0.17%

2.00%

Weighted average interest rate

3.00%

3.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Leverage ratio

2.2

'

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Letters of credit outstanding, amount

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

77,800,000

'

'

'

'

'

'

Long-term Debt, Maturities, Repayments of Principal in Year Two

10,000,000

10,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Maturities, Repayments of Principal in Year Three

10,000,000

10,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Maturities, Repayments of Principal in Year Four

10,875,000

10,875,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Maturities, Repayments of Principal in Year Five

99,750,000

99,750,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt, Maturities, Repayments of Principal after Year Five

259,188,000

259,188,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term Debt

$399,813,000

$399,813,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill_and_Identifiable_Asse2

Goodwill and Identifiable Assets (Goodwill) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill [Roll Forward]	'	'	'
Gross goodwill	$617,875	$350,951	'
Accumulated impairment loss	-121,717	-121,717	'
Goodwill	496,158	229,234	'
Goodwill, Acquired During Period	'	264,590	'
Acquisition accounting	0	1,805	0
Goodwill, Written off Related to Sale of Business Unit	-121,717	'	'
Write-off of accum impairment loss related to sale of business unit	121,717	'	'
Translation adjustment	811	529	'
Gross goodwill	574,948	617,875	350,951
Accumulated impairment loss	0	-121,717	-121,717
Goodwill	574,948	496,158	229,234
Goodwill	574,948	496,158	229,234
Whitaker [Member]	'	'	'
Goodwill [Roll Forward]	'	'	'
Goodwill, Acquired During Period	7,452	'	'
CyberCoders [Member]	'	'	'
Goodwill [Roll Forward]	'	'	'
Goodwill, Acquired During Period	70,527	'	'
Apex	'	'	'
Goodwill [Roll Forward]	'	'	'
Gross goodwill	264,590	0	'
Accumulated impairment loss	0	0	'
Goodwill	264,590	0	'
Goodwill, Acquired During Period	'	264,590	'
Translation adjustment	0	0	'
Gross goodwill	264,590	264,590	'
Accumulated impairment loss	0	0	'
Goodwill	264,590	264,590	'
Goodwill	264,590	264,590	'
Oxford	'	'	'
Goodwill [Roll Forward]	'	'	'
Gross goodwill	149,483	149,483	'
Accumulated impairment loss	0	0	'
Goodwill	149,483	149,483	'
Goodwill, Other Changes	513	'	'
Translation adjustment	0	0	'
Gross goodwill	220,523	149,483	'
Accumulated impairment loss	0	0	'
Goodwill	220,523	149,483	'
Goodwill	220,523	149,483	'
Oxford | CyberCoders [Member]	'	'	'
Goodwill [Roll Forward]	'	'	'
Goodwill, Acquired During Period	70,527	'	'
Life Sciences	'	'	'
Goodwill [Roll Forward]	'	'	'
Gross goodwill	30,011	27,668	'
Accumulated impairment loss	0	0	'
Goodwill	30,011	27,668	'
Goodwill, Acquired During Period	'	0	'
Acquisition accounting	'	1,814	'
Translation adjustment	811	529	'
Gross goodwill	30,822	30,011	'
Accumulated impairment loss	0	0	'
Goodwill	30,822	30,011	'
Goodwill	30,822	30,011	'
Healthcare	'	'	'
Goodwill [Roll Forward]	'	'	'
Gross goodwill	122,230	122,230	'
Accumulated impairment loss	-121,717	-121,717	'
Goodwill	513	513	'
Goodwill, Written off Related to Sale of Business Unit	-121,717	'	'
Write-off of accum impairment loss related to sale of business unit	121,717	'	'
Goodwill, Other Changes	-513	'	'
Translation adjustment	0	0	'
Gross goodwill	0	122,230	'
Accumulated impairment loss	0	-121,717	'
Goodwill	0	513	'
Goodwill	0	513	'
Physician	'	'	'
Goodwill [Roll Forward]	'	'	'
Gross goodwill	51,561	51,570	'
Accumulated impairment loss	0	0	'
Goodwill	51,561	51,570	'
Translation adjustment	0	0	'
Gross goodwill	59,013	51,561	'
Accumulated impairment loss	0	0	'
Goodwill	59,013	51,561	'
Goodwill	59,013	51,561	'
Physician | HCP	'	'	'
Goodwill [Roll Forward]	'	'	'
Acquisition accounting	'	-9	'
Physician | Whitaker [Member]	'	'	'
Goodwill [Roll Forward]	'	'	'
Goodwill, Acquired During Period	$7,452	'	'

Goodwill_and_Identifiable_Asse3

Goodwill and Identifiable Assets (Acquired Intangible Assets) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Intangible Assets [Line Items]	'	'	'
Amortization of intangible assets	$21,751	$18,016	$2,346
Intangible assets subject to amortization:	'	'	'
Gross Carrying Amount	176,368	144,142	'
Accumulated Amortization	73,988	52,154	'
Net Carrying Amount	102,380	91,988	'
Intangible assets not subject to amortization:	'	'	'
Trademarks, Carrying Amount	186,075	171,852	'
Goodwill	574,948	496,158	229,234
Total	'	'	'
Gross Carrying Amount	937,391	812,152	'
Net Carrying Amount	863,403	759,998	'
Customer Relationships [Member]	'	'	'
Intangible assets subject to amortization:	'	'	'
Gross Carrying Amount	110,007	103,285	'
Accumulated Amortization	41,564	23,338	'
Net Carrying Amount	68,443	79,947	'
Customer Relationships [Member] | Minimum [Member]	'	'	'
Intangible Assets [Line Items]	'	'	'
Estimated Useful Life	'3 months	'	'
Customer Relationships [Member] | Maximum [Member]	'	'	'
Intangible Assets [Line Items]	'	'	'
Estimated Useful Life	'10 years	'	'
Contractor Relations [Member]	'	'	'
Intangible assets subject to amortization:	'	'	'
Gross Carrying Amount	43,598	37,871	'
Accumulated Amortization	30,737	27,754	'
Net Carrying Amount	12,861	10,117	'
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	'7 years	'	'
Software [Member]	'	'	'
Intangible assets subject to amortization:	'	'	'
Gross Carrying Amount	18,900	'	'
Accumulated Amortization	263	'	'
Net Carrying Amount	18,637	'	'
Noncompete Agreements [Member]	'	'	'
Intangible assets subject to amortization:	'	'	'
Gross Carrying Amount	3,863	2,986	'
Accumulated Amortization	1,424	1,062	'
Net Carrying Amount	$2,439	$1,924	'
Noncompete Agreements [Member] | Minimum [Member]	'	'	'
Intangible Assets [Line Items]	'	'	'
Estimated Useful Life	'2 years	'	'
Noncompete Agreements [Member] | Maximum [Member]	'	'	'
Intangible Assets [Line Items]	'	'	'
Estimated Useful Life	'7 years	'	'

Goodwill_and_Identifiable_Asse4

Goodwill and Identifiable Assets (Future Amortization Expense) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'
Amortization of intangible assets	$21,751	$18,016	$2,346
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]	'	'	'
2013	24,509	'	'
2014	21,326	'	'
2015	17,721	'	'
2016	12,888	'	'
2017	10,307	'	'
Thereafter	15,629	'	'
Net Carrying Amount	$102,380	$91,988	'

401k_Retirement_Savings_Plan_D1

401(k) Retirement Savings Plan, Deferred Compensation Plan and Change in Control Severance Plan (Details) (USD $)	12 Months Ended					12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2012	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	15-May-12
					Chief Executive Officer [Member]	2008 Amended and Restated CIC Agreement [Member]	Apex Systems	Apex Systems	Apex Systems	Apex Systems
						Chief Executive Officer [Member]		Long-term incentive program	Long-term incentive program	Long-term incentive program
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]	'	'	'	'	'	'	'	'	'	'
Minimum service period for employee eligibility	'3 months	'	'	'	'	'	'12 months	'	'	'
Minimum hours of work	'	'	'	'	'	'	'1000 hours	'	'	'
Minimum age	'	'	'	'	'	'	'18 years	'	'	'
Employer contributions to 401(k) plans	$6,000,000	$3,700,000	$1,100,000	'	'	'	'	'	'	'
Document Fiscal Year Focus	'2013	'	'	'	'	'	'	'	'	'
Proceeds from cash surrender value of life insurance policies	'	1,500,000	'	'	'	'	'	'	'	'
Distributions to deferred compensation plan participants	'	'	'	1,200,000	'	'	'	'	'	'
Long-term incentive program, maximum award	'	'	'	'	'	'	'	'	'	10,000,000
Long-term incentive plan accrual	'	'	'	'	2,500,000	'	'	20,000	10,000,000	7,900,000
Deferred compensation	$20,000	$10,000,000	'	'	'	'	'	'	'	'
Executive Change of Control Agreement, Involuntary Termination Period	'18 months	'	'	'	'	'6 months 10 days	'	'	'	'

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Long-term Debt	'	'	'
2013	$10,000,000	'	'
2014	10,000,000	'	'
2015	10,000,000	'	'
2016	10,875,000	'	'
2017	99,750,000	'	'
Thereafter	259,188,000	'	'
Total	399,813,000	'	'
Operating Leases	'	'	'
2013	15,685,000	'	'
2014	13,863,000	'	'
2015	11,236,000	'	'
2016	7,523,000	'	'
2017	5,351,000	'	'
Thereafter	8,699,000	'	'
Total	62,357,000	'	'
Related Party	'	'	'
2013	1,299,000	'	'
2014	1,168,000	'	'
2015	694,000	'	'
2016	175,000	'	'
2017	0	'	'
Thereafter	0	'	'
Total	3,336,000	'	'
Total	'	'	'
2013	16,984,000	'	'
2014	15,031,000	'	'
2015	11,930,000	'	'
2016	7,698,000	'	'
2017	5,351,000	'	'
Thereafter	8,699,000	'	'
Total	65,693,000	'	'
Deferred rent liability, current	400,000	300,000	'
Deferred rent liability, noncurrent	3,600,000	3,800,000	'
Rent expense	16,600,000	12,800,000	7,200,000
Workers' compensation and medical malpractice liability, current	32,751,000	26,769,000	'
Letters of credit outstanding	2,700,000	2,800,000	'
Business Acquisition, Contingent Consideration, Potential Cash Payment	16,000,000	'	'
Income tax reserve in other long-term liabilities	1,600,000	400,000	'
Other Liabilities, Current	27,906,000	21,437,000	'
Pending Litigation [Member]	'	'	'
Total	'	'	'
Other Liabilities, Current	$2,100,000	'	'
Apex Systems	'	'	'
Total	'	'	'
Number of leased properties owned by related parties (in number of properties)	2	'	'

Commitments_and_Contingencies_2

Commitments and Contingencies Legal Proceedings (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Loss Contingencies [Line Items]	'	'
Other Liabilities, Current	$27,906	$21,437
Pending Litigation [Member]	'	'
Loss Contingencies [Line Items]	'	'
Other Liabilities, Current	$2,100	'

NarrativesDetails

(Narratives)(Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]	'	'	'	'
U.S. federal statutory tax rate	35.00%	35.00%	35.00%	'
Operating Loss Carryforwards [Line Items]	'	'	'	'
Valuation allowance	$1,500,000	$900,000	'	'
Accumulated net earning	146,199,000	61,687,000	'	'
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	1,300,000	300,000	200,000	'
Gross deferred tax assets	27,900,000	17,700,000	'	'
Gross deferred tax liabilities	58,800,000	30,500,000	'	'
Uncertain tax positions	1,439,000	376,000	251,000	358,000
Internal Revenue Service (IRS) [Member]	'	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'	'
Operating loss carryforwards	0	'	'	'
State	'	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'	'
Operating loss carryforwards	6,900,000	'	'	'
Foreign Tax Authority [Member]	'	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'	'
Operating loss carryforwards	6,000,000	'	'	'
Accumulated net earning	$17,800,000	'	'	'

Income_Taxes_Income_Tax_Compon

Income Taxes (Income Tax Components) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current:	'	'	'
Federal	$28,142	$17,083	$7,723
State	5,266	2,742	1,223
Foreign	1,223	2,645	1,465
Total Current	34,631	22,470	10,411
Deferred:	'	'	'
Federal	4,245	6,235	4,354
Foreign	-84	-564	68
Total Deferred	4,161	5,671	4,422
Total	$38,792	$28,141	$14,833

Income_Taxes_Income_Before_Tax

Income Taxes (Income Before Tax) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
United States	$88,637	$61,828	$31,639
Foreign	4,510	2,772	4,058
Income before income taxes	$93,147	$64,600	$35,697

Income_Taxes_Deferred_Tax_Asse

Income Taxes (Deferred Tax Assets And Liabilities) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]	'	'
Allowance for doubtful accounts	$1,578	$1,150
Employee related accruals	6,663	3,419
State taxes	611	1,064
Workers’ compensation and medical malpractice loss reserves	4,767	4,683
Other	3,595	-169
Current	17,214	10,147
Intangibles	-49,122	-23,662
Depreciation expense	-6,147	-4,449
Stock-based compensation	3,761	2,852
Net operating loss carryforwards	1,612	1,191
Other	1,822	1,975
Deferred Tax Liabilities, Gross, Noncurrent	-48,074	-22,093
Valuation allowance	-1,511	-916
Total deferred income tax assets (liabilities)	($32,371)	($12,862)

Income_Taxes_Tax_Rate_Reconcil

Income Taxes (Tax Rate Reconciliation) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]	'	'	'
Income tax provision at the statutory rate	$32,602	$22,610	$12,494
State income taxes, net of federal benefit	4,039	2,555	1,283
Permanent difference – non deductible items	1,592	1,681	1,020
Other	559	1,295	36
Total	$38,792	$28,141	$14,833

Income_Taxes_Unrecognized_Tax_

Income Taxes (Unrecognized Tax Benefit) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]	'	'	'
Unrecognized Tax Benefit beginning of year	$376	$251	$358
Gross Decreases - tax positions in prior year	-177	-34	0
Reductions for tax positions as a result of a lapse of the applicable statute of limitations	0	0	-107
Gross increases - tax positions in prior year	1,240	159	0
Unrecognized Tax Benefit end of year	$1,439	$376	$251

Earnings_per_share_Details

Earnings per share (Details)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Weighted Average Number of Shares Outstanding Reconciliation	'	'	'
Weighted average number of common shares outstanding used to compute basic earnings per share	53,481	46,739	36,876
Dilutive effect of stock-based awards	1,074	1,087	882
Number of shares used to compute diluted earnings per share	54,555	47,826	37,758
Antidilutive Securities Excluded from Computation of Earnings Per Share	'	'	'
Anti-dilutive common share equivalents outstanding	7	83	1,039

Stockbased_Compensation_Incent2

Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan (Details) (USD $)

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

0 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

12 Months Ended

Mar. 04, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Jun. 03, 2010

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

15-May-13

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Nov. 04, 2009

Jun. 03, 2010

Mar. 04, 2013

Dec. 31, 2012

Feb. 01, 2012

Feb. 01, 2011

Mar. 17, 2010

Jun. 01, 2013

Mar. 04, 2013

Jun. 21, 2013

Mar. 05, 2012

Mar. 08, 2011

15-May-12

Dec. 31, 2013

Aug. 01, 2013

Dec. 31, 2013

Feb. 02, 2014

Dec. 31, 2012

Dec. 31, 2012

Mar. 08, 2011

Dec. 31, 2012

Jan. 02, 2012

Mar. 08, 2011

Feb. 02, 2014

Dec. 31, 2012

Dec. 31, 2013

Mar. 23, 2012

Jan. 04, 2014

Dec. 31, 2012

Mar. 05, 2012

Feb. 02, 2014

Dec. 31, 2013

Mar. 04, 2013

Dec. 31, 2013

Dec. 31, 2013

2010 Incentive Award Plan [Member]

2010 Employee Stock Purchase Plan (ESPP)

2010 Employee Stock Purchase Plan (ESPP)

2010 Employee Stock Purchase Plan (ESPP)

2010 Employee Stock Purchase Plan (ESPP)

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Restricted Stock Units and Awards [Member]

Restricted Stock Units and Awards [Member]

Restricted Stock Units and Awards [Member]

Performance Based Award

RSU and RSA Excluding Directors [Member]

RSU and RSA Excluding Directors [Member]

RSU and RSA Excluding Directors [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Other Executive Officers

Other Executive Officers

Other Executive Officers

Other Executive Officers

Other Executive Officers

Other Executive Officers

Director [Member]

Director [Member]

Director [Member]

2011 Award Date [Member]

2011 Award Date [Member]

2011 Award Date [Member]

2011 Award Date [Member]

2011 Award Date [Member]

2011 Award Date [Member]

2011 Award Date [Member]

2012 Award Date [Member]

2012 Award Date [Member]

2012 Award Date [Member]

2012 Award Date [Member]

2012 Award Date [Member]

2012 Award Date [Member]

2012 Award Date [Member]

2013 Award Date [Member] [Domain]

2013 Award Date [Member] [Domain]

2013 Award Date [Member] [Domain]

Minimum [Member]

Maximum [Member]

2010 Incentive Award Plan [Member]

installment

grant

Market Based Award

Performance Based Award

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Performance Based Award

Performance Based Award

Performance Shares 2012 [Member]

Vested December 31, 2012 [Member]

Vested on January 3, 2012 [Member]

Apex Systems

Stock Options [Member]

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Chief Executive Officer [Member]

Restricted Stock Units and Awards [Member]

Restricted Stock Units and Awards [Member]

installment

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Vesting on May 31, 2013 [Member]

Performance Based Award

Performance Based Award

Performance Based Award

Performance Based Award

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Performance Based Award

Performance Based Award

Performance Based Award

Performance Based Award

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Restricted Stock Units (RSUs)

Performance Based Award

Performance Based Award

Performance Based Award

2010 Incentive Award Plan [Member]

2010 Incentive Award Plan [Member]

Restricted Stock Units (RSUs)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Compensation expense charged to operations related to stock-based compensation

'

$14,100,000

$9,500,000

$6,800,000

'

'

$1,200,000

$800,000

$400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Income tax benefit for stock-based compensation arrangements

'

5,100,000

3,500,000

2,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares to be issued

'

'

'

'

'

3,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares available for issuance

'

'

'

'

3,726,322

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vesting period

'

'

'

'

'

'

'

'

'

'

'

'

'4 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'4 years

Contractual term

'

'

'

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Grant date fair value

3,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

800,000

500,000

'

800,000

'

'

500,000

100,000

1,000,000

300,000

800,000

700,000

200,000

'

'

'

'

'

'

1,000,000

'

'

600,000

'

'

500,000

1,500,000

'

'

600,000

'

500,000

1,000,000

'

'

Share-based award expense, service period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2 years 7 months 6 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'9 months 27 days

'

'

'

'

'

'

'9 months 9 days

'

'

'

'

'

'10 months 3 days

'

'

'

Share-based awards, number of annual stock awards

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liability for share-based awards

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based awards, grants in period

143,182

'

'

'

'

'

'

'

'

'

'

'

'

621,262

'

'

59,942

'

'

'

'

'

'

'

39,448

'

'

67,568

'

'

'

'

'

'

'

26,064

'

'

'

'

'

'

'

58,754

'

'

'

'

'

'

45,372

'

'

'

'

'

Shares vested

'

'

'

'

'

'

'

'

'

'

'

'

'

538,525

'

'

'

'

'

'

'

'

'

'

'

33,784

33,784

'

'

'

'

'

'

'

'

13,032

'

16,772

24,654

'

'

29,377

29,377

'

16,772

24,654

'

'

22,686

22,686

'

16,233

'

'

'

'

Granted, weighted average grant date fair value

'

'

'

'

'

'

'

'

'

'

'

'

'

$26.77

'

'

'

$26.17

$16.01

$9.18

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$30.69

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based awards, number of equal vesting components

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

12

'

'

'

'

'

'

3

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares surrendered by the employees to the Company for payment of minimum tax withholding obligations

'

'

'

'

'

'

'

'

'

'

'

'

'

168,954

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based awards expense, service period

'

'

'

'

'

'

'

'

'

'1 year 11 months 19 days

'

'

'

'2 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'7 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options outstanding (in shares)

'

859,945

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted-average grant-date fair value of options granted

'

'

'

'

'

'

$7.16

$3.53

$2.10

'

$10.34

$5.04

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total intrinsic value of options exercised

'

'

'

'

'

'

'

'

'

7,600,000

9,700,000

1,300,000

'

15,000,000

13,700,000

6,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecognized compensation expense

'

'

'

'

'

'

'

'

'

$900,000

'

'

'

$15,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$212,391

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase price of common stock, percent

'

'

'

'

'

85.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Employee stock purchase plan (in shares)

'

'

'

'

'

'

203,200

154,934

187,036

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Document Fiscal Year Focus

'

'2013

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

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'

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'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Stockbased_Compensation_Incent3

Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan (Assumptions) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
		Stock Options [Member]	Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Document Fiscal Year Focus	'2013	'	'
Dividend yield	'	0.00%	0.00%
Risk-free interest rate	'	1.19%	0.92%
Expected volatility	'	64.15%	75.67%
Expected lives	'	'7 years 3 months 18 days	'3 years 7 months 6 days

Stockbased_Compensation_Incent4

Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan (Range of Prices) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Exercise price, low end of the range (in dollars per share)	$4.44	'
Exercise price, high end of the range (in dollars per share)	$16.51	'
Options outstanding (in shares)	859,945	'
Options outstanding - weighted average remaining contractual life (years)	'4 years 9 months 18 days	'5 years 7 months 6 days
Options outstanding - weighted average exercise price (in dollars per share)	$10.61	$9.83
Options exercisable - at the end of period (in shares)	691,349	'
Options exercisable - weighted average exercise price (in dollars per share)	$10.34	'
$2.82 - 6.68	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Exercise price, low end of the range (in dollars per share)	$4.44	'
Exercise price, high end of the range (in dollars per share)	$8.26	'
Options outstanding (in shares)	255,250	'
Options outstanding - weighted average remaining contractual life (years)	'4 years 9 months 18 days	'
Options outstanding - weighted average exercise price (in dollars per share)	$6.62	'
Options exercisable - at the end of period (in shares)	214,351	'
Options exercisable - weighted average exercise price (in dollars per share)	$6.34	'
$6.86 - 10.20	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Exercise price, low end of the range (in dollars per share)	$8.38	'
Exercise price, high end of the range (in dollars per share)	$11.39	'
Options outstanding (in shares)	272,121	'
Options outstanding - weighted average remaining contractual life (years)	'5 years 1 month 6 days	'
Options outstanding - weighted average exercise price (in dollars per share)	$10.90	'
Options exercisable - at the end of period (in shares)	196,831	'
Options exercisable - weighted average exercise price (in dollars per share)	$11.08	'
$10.46 - 11.39	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Exercise price, low end of the range (in dollars per share)	$11.56	'
Exercise price, high end of the range (in dollars per share)	$12.90	'
Options outstanding (in shares)	213,724	'
Options outstanding - weighted average remaining contractual life (years)	'3 years 1 month 6 days	'
Options outstanding - weighted average exercise price (in dollars per share)	$12.39	'
Options exercisable - at the end of period (in shares)	213,724	'
Options exercisable - weighted average exercise price (in dollars per share)	$12.39	'
$11.56 - 12.90	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Exercise price, low end of the range (in dollars per share)	$13.31	'
Exercise price, high end of the range (in dollars per share)	$13.58	'
Options outstanding (in shares)	43,850	'
Options outstanding - weighted average remaining contractual life (years)	'3 years 3 months 18 days	'
Options outstanding - weighted average exercise price (in dollars per share)	$13.32	'
Options exercisable - at the end of period (in shares)	43,006	'
Options exercisable - weighted average exercise price (in dollars per share)	$13.31	'
$12.91 - 16.51	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Exercise price, low end of the range (in dollars per share)	$16.51	'
Exercise price, high end of the range (in dollars per share)	$16.51	'
Options outstanding (in shares)	75,000	'
Options outstanding - weighted average remaining contractual life (years)	'8 years 8 months 12 days	'
Options outstanding - weighted average exercise price (in dollars per share)	$16.51	'
Options exercisable - at the end of period (in shares)	23,437	'
Options exercisable - weighted average exercise price (in dollars per share)	$16.51	'

Stockbased_Compensation_Incent5

Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan (Stock Options Activity) (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Outstanding Stock Options Activity [Roll Forward]	'	'
Outstanding at December 31, 2012 (in shares)	859,945	'
Exercisable at December 31, 2012 (in shares)	691,349	'
Options Outstanding, Weighted Average Exercise Price [Roll Forward]	'	'
Outstanding - weighted average exercise price per share at January 1, 2012	$9.83	'
Exercised, weighted average exercise price per share	$8.13	'
Canceled, weighted average exercise price per share	$9.65	'
Outstanding - weighted average exercise price per share at December 31, 2012	$10.61	$9.83
Vested and Expected to Vest, weighted average exercise price per share	$10.56	'
Exercisable, weighted average exercise price per share	$10.34	'
Outstanding, weighted average remaining contractual term at January 1, 2012	'4 years 9 months 18 days	'5 years 7 months 6 days
Outstanding, weighted average remaining contractual term at December 31, 2012	'4 years 9 months 18 days	'5 years 7 months 6 days
Vested and Expected to Vest, weighted average remaining contractual term	'4 years 8 months 12 days	'
Exercisable, weighted average remaining contractual term	'4 years	'
Options outstanding - aggregate intrinsic value at January 1, 2012	$13,442	'
Options outstanding - aggregate intrinsic value at December 31, 2012	20,903	13,442
Vested and Expected to Vest, aggregate intrinsic value	20,521	'
Exercisable, aggregate intrinsic value	$16,995	'
Incentive Stock Options [Member]	'	'
Outstanding Stock Options Activity [Roll Forward]	'	'
Outstanding at January 1, 2012 (in shares)	129,423	'
Exercised (in shares)	-59,806	'
Canceled (in shares)	-201	'
Outstanding at December 31, 2012 (in shares)	69,416	'
Vested and Expected to Vest at December 31, 2012 (in shares)	69,416	'
Exercisable at December 31, 2012 (in shares)	69,386	'
Non Qualified Stock Options [Member]	'	'
Outstanding Stock Options Activity [Roll Forward]	'	'
Outstanding at January 1, 2012 (in shares)	1,156,937	'
Exercised (in shares)	-333,377	'
Canceled (in shares)	-33,031	'
Outstanding at December 31, 2012 (in shares)	790,529	'
Vested and Expected to Vest at December 31, 2012 (in shares)	772,942	'
Exercisable at December 31, 2012 (in shares)	621,963	'

Stockbased_Compensation_Incent6

Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan Stock-based Compensation: Incentive Award Plan and Employee Stock Purchase Plan (RSU and RSAs) (Details) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 04, 2013	Dec. 31, 2013	15-May-13	Jun. 01, 2013	Mar. 04, 2013
		Restricted Stock Units and Awards [Member]	Performance Based Award	Other Executive Officers	Other Executive Officers
				Performance Based Award	Performance Based Award
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]	'	'	'	'	'
Unvested RSUs and RSAs outstanding at January 1, 2012 (in shares)	'	1,390,834	'	'	'
Granted (in shares)	143,182	621,262	59,942	'	'
Market value share count adjustment for liability awards (in shares)	'	-55,664	'	'	'
Vested (in shares)	'	-538,525	'	'	'
Forfeited (in shares)	'	-50,669	'	'	'
Unvested RSUs and RSAs outstanding at December 31, 2012 (in shares)	'	1,367,238	'	'	'
Unvested and expected to vest RSUs and RSAs outstanding at December 31, 2012 (in shares)	'	1,201,190	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'	'	'	'	'
Unvested RSUs and RSAs outstanding at January 1, 2012, weighted average grant date fair value (in dollars per share)	'	$14.31	'	'	'
Granted, weighted average grant date fair value (in dollars per share)	'	$26.77	'	'	'
Market value share count adjustment for liability awards, weighted average grant date fair value (in dollars per share)	'	$34.92	'	'	'
Vested, weighted average grant date fair value (in dollars per share)	'	$14.76	'	'	'
Forfeited, weighted average grant date fair value (in dollars per share)	'	$15.75	'	'	'
Unvested RSUs and RSAs outstanding at December 31, 2012, weighted average grant date fair value (in dollars per share)	'	$18.90	'	'	'
Unvested and expected to vest RSUs and RSAs outstanding at December 31, 2012, weighted average grant date fair value (in dollars per share)	'	$19.12	'	'	'
Grant date fair value	$3.20	'	'	$0.10	$1

Business_Segments_Segment_Repo

Business Segments (Segment Reporting Information) (Details) (USD $)

3 Months Ended

12 Months Ended

In Thousands, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

segment

Segment Reporting Information

'

'

'

'

'

'

'

'

'

'

'

Revenues

$423,598

$421,491

$407,864

$379,044

$369,441

$363,882

$256,386

$148,277

$1,631,997

$1,137,986

$515,584

Gross profit

129,753

127,210

121,332

110,111

112,054

112,213

81,509

50,117

488,406

355,893

177,688

Operating Income

'

'

'

'

'

'

'

'

123,968

81,181

38,633

Amortization of intangible assets

'

'

'

'

'

'

'

'

21,751

18,016

2,346

Assets

1,261,194

[1]

'

'

'

1,114,463

[1]

'

'

'

1,261,194

[1]

1,114,463

[1]

427,267

[1]

Reportable segments (in number of segments)

'

'

'

'

'

'

'

'

4

'

'

Apex

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

942,463

508,743

'

Gross profit

'

'

'

'

'

'

'

'

258,150

140,669

'

Operating Income

'

'

'

'

'

'

'

'

76,971

36,416

'

Amortization of intangible assets

'

'

'

'

'

'

'

'

19,524

15,665

'

Assets

656,733

[1]

'

'

'

642,594

[1]

'

'

'

656,733

[1]

642,594

[1]

'

Oxford

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

412,189

363,765

279,643

Gross profit

'

'

'

'

'

'

'

'

143,334

127,895

99,187

Operating Income

'

'

'

'

'

'

'

'

58,990

56,289

37,676

Amortization of intangible assets

'

'

'

'

'

'

'

'

965

437

821

Assets

365,118

[1]

'

'

'

235,099

[1]

'

'

'

365,118

[1]

235,099

[1]

221,690

[1]

Life Sciences

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

171,518

162,799

155,324

Gross profit

'

'

'

'

'

'

'

'

56,308

55,874

52,643

Operating Income

'

'

'

'

'

'

'

'

28,354

25,632

24,883

Amortization of intangible assets

'

'

'

'

'

'

'

'

429

807

901

Assets

128,824

[1]

'

'

'

150,696

[1],[2]

'

'

'

128,824

[1]

150,696

[1],[2]

119,563

[1],[2]

Physician

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

105,827

102,679

80,617

Gross profit

'

'

'

'

'

'

'

'

30,614

31,455

25,858

Operating Income

'

'

'

'

'

'

'

'

8,852

9,998

6,699

Amortization of intangible assets

'

'

'

'

'

'

'

'

742

817

415

Assets

110,519

[1]

'

'

'

86,074

[1]

'

'

'

110,519

[1]

86,074

[1]

86,014

[1]

Corporate

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information

'

'

'

'

'

'

'

'

'

'

'

Operating Income

'

'

'

'

'

'

'

'

-49,199

-47,154

-30,625

Amortization of intangible assets

'

'

'

'

'

'

'

'

$91

$290

$209

[1]

As of end of the year.

[2]

Life Sciences total assets as of December 31, 2012 and 2011 include assets related to the Healthcare segment, which were sold and included in discontinued operations in 2013. Historically, the Company has not reported Life Science and Healthcare segments' total assets separately as the operations were largely centralized.

Business_Segments_Revenue_by_G

Business Segments (Revenue by Geographical Areas) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:	'	'	'	'	'	'	'	'	'	'	'
Domestic	'	'	'	'	'	'	'	'	$1,552,322	$1,060,217	$447,453
Foreign	'	'	'	'	'	'	'	'	79,675	77,769	68,131
Total Revenues	$423,598	$421,491	$407,864	$379,044	$369,441	$363,882	$256,386	$148,277	$1,631,997	$1,137,986	$515,584

Business_Segments_LongLived_As

Business Segments (Long-Lived Assets) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Segment Reporting [Abstract]	'	'	'
Domestic	$45,061	$40,062	$19,078
Foreign	2,856	2,006	1,033
Total Long-lived Assets	$47,917	$42,068	$20,111

Fair_Value_Measurements_Fair_V1

Fair Value Measurements (Fair Value Inputs, Liabilities, Quantitative Information) (Details) (USD $)

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Contingent Consideration Liability [Member]

Contingent Consideration Liability [Member]

Contingent Consideration Liability [Member]

Fair Value, Inputs, Level 2

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Whitaker [Member]

Whitaker [Member]

Whitaker [Member]

CyberCoders [Member]

CyberCoders [Member]

CyberCoders [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Contingent Consideration Liability [Member]

Contingent Consideration Liability [Member]

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 2

Fair Value, Inputs, Level 2

Significant Unobservable Inputs (Level 3)

Significant Unobservable Inputs (Level 3)

Estimate of Fair Value, Fair Value Disclosure [Member]

Estimate of Fair Value, Fair Value Disclosure [Member]

Minimum

Maximum [Member]

Contingent Consideration Liability [Member]

Contingent Consideration Liability [Member]

Contingent Consideration Liability [Member]

Contingent Consideration Liability [Member]

Contingent Consideration Liability [Member]

Contingent Consideration Liability [Member]

Minimum

Maximum [Member]

Minimum

Maximum [Member]

Fair Value Inputs, Liabilities, Quantitative Information

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value

'

$8,527,000

$7,577,000

$9,856,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Obligations, Fair Value Disclosure

'

'

'

'

'

'

'

'

'

'

'

'

'

0

0

0

0

8,527,000

7,577,000

8,527,000

7,577,000

Long-term debt

399,813,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term debt, fair value

'

'

'

'

400,200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Probability of occurrence of scenarios (as a percentage)

'

'

'

'

'

10.00%

60.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value Inputs, Weighting Given to Base Case Scenario

'

'

'

'

'

'

'

60.00%

'

'

50.00%

'

'

'

'

'

'

'

'

'

'

Revenue growth rates (as a percentage)

'

'

'

'

'

'

'

'

2.00%

15.00%

'

9.60%

25.00%

'

'

'

'

'

'

'

'

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Acquisitions

'

7,860,000

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Payments

'

3,425,000

1,198,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements

'

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings

'

-3,584,000

-1,215,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)

'

$99,000

$134,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair_Value_Measurements_Recurr

Fair Value Measurements (Recurring Basis) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
In Thousands, unless otherwise specified	Quoted Prices in Active Markets for Identical Assets (Level 1)	Quoted Prices in Active Markets for Identical Assets (Level 1)	Significant Other Observable Inputs (Level 2)	Significant Other Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)	Significant Unobservable Inputs (Level 3)	Estimate of Fair Value, Fair Value Disclosure [Member]	Estimate of Fair Value, Fair Value Disclosure [Member]	Whitaker [Member]
	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Fair Value, Measurements, Recurring [Member]	Contingent Consideration Liability [Member]
									Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis	'	'	'	'	'	'	'	'	'
Fair Value Inputs, Weighting Given to Base Case Scenario	'	'	'	'	'	'	'	'	60.00%
Contingent consideration to be paid in cash for the acquisitions	$0	$0	$0	$0	($8,527)	($7,577)	($8,527)	($7,577)	'

Fair_Value_Measurements_Liabil

Fair Value Measurements (Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation) (Details) (Contingent Consideration Liability [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Contingent Consideration Liability [Member]	'	'
Contingent consideration for acquisitions	'	'
Balance at beginning of period	($7,577)	($9,856)
Additions for acquisitions	-7,860	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Payments	3,425	1,198
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	0	0
Fair value adjustment	3,584	1,215
Foreign currency translation adjustment	-99	-134
Balance at end of period	($8,527)	($7,577)

Unaudited_Quarterly_Financial_2

Unaudited Quarterly Financial Results (Details) (USD $)

0 Months Ended

3 Months Ended

12 Months Ended

Dec. 31, 2012

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Quarterly Financial Information Disclosure [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

$423,598,000

$421,491,000

$407,864,000

$379,044,000

$369,441,000

$363,882,000

$256,386,000

$148,277,000

$1,631,997,000

$1,137,986,000

$515,584,000

Gross profit

'

129,753,000

127,210,000

121,332,000

110,111,000

112,054,000

112,213,000

81,509,000

50,117,000

488,406,000

355,893,000

177,688,000

Income from continuing operations

'

17,425,000

19,471,000

7,243,000

10,216,000

12,004,000

14,078,000

5,586,000

4,791,000

54,355,000

36,459,000

20,864,000

Income from discontinued operations, net of income taxes

'

14,985,000

679,000

96,000

14,397,000

2,201,000

1,425,000

1,976,000

592,000

-683,000

6,194,000

3,433,000

Net income

'

32,410,000

20,150,000

7,339,000

24,613,000

14,205,000

15,503,000

7,562,000

5,383,000

84,512,000

42,653,000

24,297,000

Earnings Per Share, Basic [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

Income from continuing operations

'

$0.32

$0.36

$0.14

$0.19

$0.23

$0.27

$0.12

$0.13

$1.02

$0.78

$0.57

Income from discontinued operations

'

$0.28

$0.02

$0

$0.27

$0.04

$0.03

$0.05

$0.01

$0.56

$0.13

$0.09

Net income

'

$0.60

$0.38

$0.14

$0.46

$0.27

$0.30

$0.17

$0.14

$1.58

$0.91

$0.66

Earnings Per Share, Diluted [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

Income from continuing operations

'

$0.32

$0.36

$0.13

$0.19

$0.22

$0.26

$0.12

$0.13

$1

$0.76

$0.55

Income from discontinued operations

'

$0.27

$0.01

$0.01

$0.27

$0.04

$0.03

$0.04

$0.01

$0.55

$0.13

$0.09

Net income

'

$0.59

$0.37

$0.14

$0.46

$0.26

$0.29

$0.16

$0.14

$1.55

$0.89

$0.64

Segment Reporting Information

'

'

'

'

'

'

'

'

'

'

'

'

Classification error related to vendor fees

16,400,000

'

'

'

'

'

'

'

'

'

'

'

Apex Segment [Member]

'

'

'

'

'

'

'

'

'

'

'

'

Quarterly Financial Information Disclosure [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

Revenues

'

'

'

'

'

'

'

'

'

942,463,000

508,743,000

'

Gross profit

'

'

'

'

'

'

'

'

'

258,150,000

140,669,000

'

Segment Reporting Information

'

'

'

'

'

'

'

'

'

'

'

'

Restatement of Prior Year Income, Gross

'

'

'

'

'

-5,000,000

3,400,000

1,600,000

'

'

'

'

Restatement of Prior Year Income, Net of Tax

'

'

'

'

'

-2,900,000

1,900,000

1,000,000

'

'

'

'

Vendor Fees [Member] | Apex Systems

'

'

'

'

'

'

'

'

'

'

'

'

Segment Reporting Information

'

'

'

'

'

'

'

'

'

'

'

'

Classification error related to vendor fees

'

'

'

'

'

'

'

$500,000

'

'

'

'

Schedule_II_Valuation_and_Qual1

Schedule II - Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts and Bilinig Adjustments	'	'	'
Movement in Valuation Allowances and Reserves [Roll Forward]	'	'	'
Balance at beginning of year	$3,970	$2,777	$2,175
Provisions	1,787	-166	1,127
Deductions	-2,690	1,359	-525
Balance at end of year	3,067	3,970	2,777
Allowance for Workers' Compensation and Medical Malpractice Loss Reserves	'	'	'
Movement in Valuation Allowances and Reserves [Roll Forward]	'	'	'
Balance at beginning of year	26,769	27,003	28,244
Provisions	5,956	3,594	2,339
Deductions	26	-3,828	-3,580
Balance at end of year	$32,751	$26,769	$27,003