XML 61 R35.htm IDEA: XBRL DOCUMENT
v3.19.1

Schedule II - Valuation and Qualifying Accounts (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2018
Notes Tables |
Valuation and Qualifying Accounts Disclosure [Table Text Block] |
|  | Balance at Beginning of Period |  |  | (Recovered From)/ Charged to Costs and Expenses |  |  | Deductions (1) |  |  | Balance at End of Period |
Year ended December 31, 2018: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deducted from asset accounts: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Allowance for doubtful accounts |  | $ | 342 |  |  |  | 196 |  |  |  | 5 |  |  | $ | 533 |
Year ended December 31, 2017: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deducted from asset accounts: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Allowance for doubtful accounts |  | $ | 288 |  |  |  | 113 |  |  |  | 59 |  |  | $ | 342 |

X
- Definition Tabular disclosure of a schedule of allowance and reserve accounts where the valuation and qualifying accounts are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs. + References No definition available. + Details
Name: | sgrp_ValuationAndQualifyingAccountsDisclosureTableTextBlock
Namespace Prefix: | sgrp_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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