XML 30 R8.htm IDEA: XBRL DOCUMENT
v3.21.2

Cash, Cash Equivalents and Marketable Securities (Notes) | 9 Months Ended
--- | ---
Sep. 30, 2021
Cash, Cash Equivalents and Marketable Securities [Abstract] |
Cash, Cash Equivalents and Marketable Securities |
3. | Cash, Cash Equivalents and Marketable Securities
The following table summarizes our cash and investments in cash equivalents and marketable securities held by investment managers and overnight investments:
| September 30, 2021 |  | December 31, 2020
(in thousands) | Cash & Cash Equivalents | Marketable Securities | Total |  | Cash & Cash Equivalents | Marketable Securities | Total
Overnight holdings | $ | 404,564 |  | $ | — |  | $ | 404,564 |  |  | $ | 503,221 |  | $ | — |  | $ | 503,221 |
Investment holdings | 49,913 |  | 32,697 |  | 82,610 |  |  | 47,992 |  | 34,529 |  | 82,521 |
Cash in demand accounts | 30,377 |  | — |  | 30,377 |  |  | 33,692 |  | — |  | 33,692 |
Outstanding checks | (16,933) |  | — |  | (16,933) |  |  | (30,059) |  | — |  | (30,059) |
Total | $ | 467,921 |  | $ | 32,697 |  | $ | 500,618 |  |  | $ | 554,846 |  | $ | 34,529 |  | $ | 589,375 |
Our cash and overnight holdings fluctuate based on the timing of clients’ payroll processing cycles. Our cash, cash equivalents and marketable securities at September 30, 2021 and December 31, 2020 included $198.4 million and $342.0 million, respectively, of funds associated with federal and state income tax withholdings, employment taxes and other payroll deductions, as well as $74.6 million and $35.3 million, respectively, in client prepayments.

X
- References No definition available. + Details
Name: | nsp_CashCashEquivalentsAndMarketableSecuritiesAbstract
Namespace Prefix: | nsp_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure of cash, cash equivalents, and debt and equity securities, including any unrealized or realized gain (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -URI http://asc.fasb.org/topic&trid=2196928 + Details
Name: | us-gaap_CashCashEquivalentsAndMarketableSecuritiesTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration