XML 35 R36.htm IDEA: XBRL DOCUMENT v2.4.1.9

Fair Value Measurements (Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration maximum	$ 11.0asgn_Contingentconsiderationmaximum
Significant Unobservable Inputs (Level 3) | Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration to be paid in cash for the acquisitions	$ 3.0us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisObligations / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember	$ (3.0)us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisObligations / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember

X

- Definition

For contingent consideration arrangements recognized in connection with a business combination, this element represents the maximum amount of consideration which may be paid.

+ References

No definition available.

+ Details

Name:	asgn_Contingentconsiderationmaximum
Namespace Prefix:	asgn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

Name:	us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Fair value of obligations measured on a recurring basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisObligations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: