XML 45 R21.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Stockholders' Equity Stockholders' Equity (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2014
Stockholders' Equity Attributable to Parent [Abstract] |
Quarterly dividends declared [Table Text Block] | The Board declared quarterly dividends as follows:
|  | 2014 |  | 2013
|  | (amounts per share)
First quarter |  | $ | 0.17 |  |  | $ | 0.17 |
Second quarter |  | 0.19 |  |  | 0.17 |
Third quarter |  | 0.19 |  |  | 0.17 |

X
- Definition Quarterly dividends declared [Table Text Block] - tabular disclosure of all or some of the information related to dividends declared and paid as of the financial reporting date. + References No definition available. + Details
Name: | nsp_QuarterlydividendsdeclaredTableTextBlock
Namespace Prefix: | nsp_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StockholdersEquityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration