XML 33 R21.htm IDEA: XBRL DOCUMENT
v3.20.2

Earnings Per Share Schedule Of Earnings Per Share Basic And Diluted Table (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2020
Calculation of Basic and Diluted Earnings per Share [Abstract] |
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] | The following is a reconciliation of the number of shares and share equivalents used to calculate basic and diluted earnings per share (in millions, except per share data):
| Three Months Ended |  | Six Months Ended
| June 30, |  | June 30,
| 2020 |  | 2019 |  | 2020 |  | 2019
Net income | $ | 48.8 |  |  | $ | 43.1 |  |  | $ | 92.6 |  |  | $ | 78.0 |
Weighted-average number of common shares outstanding - basic | 52.5 |  |  | 52.8 |  |  | 52.7 |  |  | 52.7 |
Dilutive effect of share equivalents | 0.5 |  |  | 0.6 |  |  | 0.4 |  |  | 0.6 |
Number of common shares and share equivalents outstanding - diluted | 53.0 |  |  | 53.4 |  |  | 53.1 |  |  | 53.3 |
Basic earnings per share | $0.93 |  | $0.82 |  | $1.76 |  | $1.48
Diluted earnings per share | $0.92 |  | $0.81 |  | $1.74 |  | $1.46
Anti-dilutive share equivalents (1) | 0.5 |  |  | 0.2 |  |  | 0.3 |  |  | 0.3 |
_____ (1) Anti-dilutive stock-based awards that were excluded from the calculation of the number of shares used to compute diluted earnings per share because they were anti-dilutive when applying the treasury-stock

X
- Definition Calculation of Basic and Diluted Earnings per Share [Abstract] + References No definition available. + Details
Name: | asgn_CalculationofBasicandDilutedEarningsperShareAbstract
Namespace Prefix: | asgn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of an entity's basic and diluted earnings per share calculations, including a reconciliation of numerators and denominators of the basic and diluted per-share computations for income from continuing operations. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
Name: | us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration