| Pay vs Performance Disclosure | 12 Months Ended |
| Dec. 31, 2022 USD ($) item | Dec. 31, 2021 USD ($) item | Dec. 31, 2020 USD ($) item |
| Pay vs Performance Disclosure [Table] | | | |
| Pay vs Performance [Table Text Block] | Average Summary Average Compensation Compensation Value of Initial Fixed $100 Summary Table Total for Actually Paid to Investment Based on: Compensation Compensation Non-PEO Named Non-PEO Named Total Peer Group Total SG&A Table Total Actually Paid Executive Executive Shareholder Shareholder Net Percentage of Year for PEO (1) to PEO (2) Officers (1) Officers (2) Return (TSR) Return Income Billings (4) 2022 $ 4,787,929 $ 5,547,279 $ 1,338,317 $ 1,416,376 $ 97.66 $ 119.45 $ 89,219,000 10.46% 2021 $ 3,209,550 $ 2,339,350 $ 1,802,672 $ 1,649,422 $ 89.27 $ 177.06 $ 69,906,000 10.34% 2020 $ 1,388,550 $ 480,650 $ 479,491 $ 408,849 $ 95.22 $ 144.92 $ 55,765,000 10.97% (1) Our PEO was Timothy McGrath for all years presented in the table. Our NEOs were Thomas Baker and Patricia Gallup for all years presented in the table. (2) The following table describes the adjustments, each of which is prescribed by SEC rule, to calculate the CAP Amounts from the SCT Amounts. The SCT Amounts and the CAP Amounts do not reflect the actual amount of compensation earned by or paid to our executives during the applicable years, but rather are amounts determined in accordance with Item 402 of Regulation S-K under the Exchange Act. PEO Average of NEO's 2022 2021 2020 2022 2021 2020 Total Compensation from SCT $ 4,787,929 $ 3,209,550 $ 1,388,550 $ 1,338,317 $ 1,802,672 $ 479,491 Decrease for aggregate value for stock awards and option awards included in SCT for the covered fiscal year $ (2,165,200) $ (887,200) $ - $ (541,300) $ (1,074,200) $ - Increase for fair value at year end of awards granted during the covered fiscal year that were outstanding and unvested at the covered fiscal year end $ 1,876,000 $ 862,600 $ - $ 469,000 $ 970,425 $ - Increase (decrease) in year-over-year change in fair value at covered fiscal year end of awards granted in any prior fiscal year that were outstanding and unvested at the covered fiscal year end $ 603,200 $ (790,400) $ (604,350) $ 84,825 $ (42,640) $ (35,254) Increase for vesting date fair value of awards granted and vested during the covered fiscal year $ - $ - $ - $ - $ - $ - Increase (decrease) in change as of the vesting date (from the end of the prior fiscal year) in fair value of awards granted in any prior fiscal year for which vesting conditions were satisfied during the covered fiscal year $ 445,350 $ (55,200) $ (303,550) $ 65,534 $ (6,835) $ (35,388) Decrease for fair value at end of prior fiscal year of awards granted in any prior fiscal year that failed to meet the applicable vesting conditions during the covered fiscal year $ - $ - $ - $ - $ - $ - Increase for dividends or other earnings paid on stock or option awards in the covered fiscal year prior to vesting if not otherwise included in the total compensation for the covered fiscal year $ - $ - $ - $ - $ - $ - Compensation Actually Paid $ 5,547,279 $ 2,339,350 $ 480,650 $ 1,416,376 $ 1,649,422 $ 408,849 (3) Our peer group for the calculation of Total Shareholder Return, or TSR, is the NASDAQ Composite-Total Return. (4) SG&A percentage of billings , a non-GAAP financial measure, is calculated as total SG&A expenses (less any exclusions approved by the Subcommittee) divided by total billings of products and services delivered to customers. We define total billings delivered to customers as net sales plus the amount we are required to net for sales of software under ASC 606. In 2021, the Subcommittee approved $5 million of uncontrolled medical expenses to be excluded from total SG&A expenses. | | |
| Company Selected Measure Name | SG&A percentage of billings | | |
| Named Executive Officers, Footnote [Text Block] | (1) Our PEO was Timothy McGrath for all years presented in the table. Our NEOs were Thomas Baker and Patricia Gallup for all years presented in the table. | | |
| Peer Group Issuers, Footnote [Text Block] | (3) Our peer group for the calculation of Total Shareholder Return, or TSR, is the NASDAQ Composite-Total Return. | | |
| PEO Total Compensation Amount | $ 4,787,929 | $ 3,209,550 | $ 1,388,550 |
| PEO Actually Paid Compensation Amount | $ 5,547,279 | 2,339,350 | 480,650 |
| Adjustment To PEO Compensation, Footnote [Text Block] | (2) The following table describes the adjustments, each of which is prescribed by SEC rule, to calculate the CAP Amounts from the SCT Amounts. The SCT Amounts and the CAP Amounts do not reflect the actual amount of compensation earned by or paid to our executives during the applicable years, but rather are amounts determined in accordance with Item 402 of Regulation S-K under the Exchange Act. PEO Average of NEO's 2022 2021 2020 2022 2021 2020 Total Compensation from SCT $ 4,787,929 $ 3,209,550 $ 1,388,550 $ 1,338,317 $ 1,802,672 $ 479,491 Decrease for aggregate value for stock awards and option awards included in SCT for the covered fiscal year $ (2,165,200) $ (887,200) $ - $ (541,300) $ (1,074,200) $ - Increase for fair value at year end of awards granted during the covered fiscal year that were outstanding and unvested at the covered fiscal year end $ 1,876,000 $ 862,600 $ - $ 469,000 $ 970,425 $ - Increase (decrease) in year-over-year change in fair value at covered fiscal year end of awards granted in any prior fiscal year that were outstanding and unvested at the covered fiscal year end $ 603,200 $ (790,400) $ (604,350) $ 84,825 $ (42,640) $ (35,254) Increase for vesting date fair value of awards granted and vested during the covered fiscal year $ - $ - $ - $ - $ - $ - Increase (decrease) in change as of the vesting date (from the end of the prior fiscal year) in fair value of awards granted in any prior fiscal year for which vesting conditions were satisfied during the covered fiscal year $ 445,350 $ (55,200) $ (303,550) $ 65,534 $ (6,835) $ (35,388) Decrease for fair value at end of prior fiscal year of awards granted in any prior fiscal year that failed to meet the applicable vesting conditions during the covered fiscal year $ - $ - $ - $ - $ - $ - Increase for dividends or other earnings paid on stock or option awards in the covered fiscal year prior to vesting if not otherwise included in the total compensation for the covered fiscal year $ - $ - $ - $ - $ - $ - Compensation Actually Paid $ 5,547,279 $ 2,339,350 $ 480,650 $ 1,416,376 $ 1,649,422 $ 408,849 | | |
| Non-PEO NEO Average Total Compensation Amount | $ 1,338,317 | 1,802,672 | 479,491 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 1,416,376 | 1,649,422 | 408,849 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | (2) The following table describes the adjustments, each of which is prescribed by SEC rule, to calculate the CAP Amounts from the SCT Amounts. The SCT Amounts and the CAP Amounts do not reflect the actual amount of compensation earned by or paid to our executives during the applicable years, but rather are amounts determined in accordance with Item 402 of Regulation S-K under the Exchange Act. PEO Average of NEO's 2022 2021 2020 2022 2021 2020 Total Compensation from SCT $ 4,787,929 $ 3,209,550 $ 1,388,550 $ 1,338,317 $ 1,802,672 $ 479,491 Decrease for aggregate value for stock awards and option awards included in SCT for the covered fiscal year $ (2,165,200) $ (887,200) $ - $ (541,300) $ (1,074,200) $ - Increase for fair value at year end of awards granted during the covered fiscal year that were outstanding and unvested at the covered fiscal year end $ 1,876,000 $ 862,600 $ - $ 469,000 $ 970,425 $ - Increase (decrease) in year-over-year change in fair value at covered fiscal year end of awards granted in any prior fiscal year that were outstanding and unvested at the covered fiscal year end $ 603,200 $ (790,400) $ (604,350) $ 84,825 $ (42,640) $ (35,254) Increase for vesting date fair value of awards granted and vested during the covered fiscal year $ - $ - $ - $ - $ - $ - Increase (decrease) in change as of the vesting date (from the end of the prior fiscal year) in fair value of awards granted in any prior fiscal year for which vesting conditions were satisfied during the covered fiscal year $ 445,350 $ (55,200) $ (303,550) $ 65,534 $ (6,835) $ (35,388) Decrease for fair value at end of prior fiscal year of awards granted in any prior fiscal year that failed to meet the applicable vesting conditions during the covered fiscal year $ - $ - $ - $ - $ - $ - Increase for dividends or other earnings paid on stock or option awards in the covered fiscal year prior to vesting if not otherwise included in the total compensation for the covered fiscal year $ - $ - $ - $ - $ - $ - Compensation Actually Paid $ 5,547,279 $ 2,339,350 $ 480,650 $ 1,416,376 $ 1,649,422 $ 408,849 | | |
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | Compensation Actually Paid vs TSR | | |
| Compensation Actually Paid vs. Net Income [Text Block] | Compensation Actually Paid vs Net Income | | |
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | Compensation Actually Paid vs SG&A Percentage of Billings | | |
| Tabular List [Table Text Block] | The following lists the financial performance measures that, in our assessment, represent the most important performance measures we use to link the CAP Amounts for our named executive officers for 2022 (our most recently completed fiscal year), to company performance: Company Performance Measures Net income SG&A percentage of billings Of these measures, we have identified SG&A percentage of billings as the most important of our financial performance measures (that is not already required to be disclosed in the pay versus performance table above) used to link CAP Amounts for our executives for 2022 to company performance. | | |
| Total Shareholder Return Amount | $ 97.66 | 89.27 | 95.22 |
| Peer Group Total Shareholder Return Amount | 119.45 | 177.06 | 144.92 |
| Net Income (Loss) | $ 89,219,000 | $ 69,906,000 | $ 55,765,000 |
| Company Selected Measure Amount | item | 10.46 | 10.34 | 10.97 |
| PEO Name | Timothy McGrath | | |
| Measure [Axis]: 1 | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Measure Name | Net income | | |
| Measure [Axis]: 2 | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Measure Name | SG&A percentage of billings | | |
| Non-GAAP Measure Description [Text Block] | (4) SG&A percentage of billings , a non-GAAP financial measure, is calculated as total SG&A expenses (less any exclusions approved by the Subcommittee) divided by total billings of products and services delivered to customers. We define total billings delivered to customers as net sales plus the amount we are required to net for sales of software under ASC 606. In 2021, the Subcommittee approved $5 million of uncontrolled medical expenses to be excluded from total SG&A expenses. | | |
| PEO [Member] | Decrease for aggregate value for stock awards and option awards included in SCT for the covered fiscal year | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | $ (2,165,200) | $ (887,200) | |
| PEO [Member] | Increase for fair value at year end of awards granted during the covered fiscal year that were outstanding and unvested at the covered fiscal year end | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 1,876,000 | 862,600 | |
| PEO [Member] | Increase (decrease) in year-over-year change in fair value at covered fiscal year end of awards granted in any prior fiscal year that were outstanding and unvested at the covered fiscal year end | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 603,200 | (790,400) | $ (604,350) |
| PEO [Member] | Increase (decrease) in change as of the vesting date (from the end of the prior fiscal year) in fair value of awards granted in any prior fiscal year for which vesting conditions were satisfied during the covered fiscal year | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 445,350 | (55,200) | (303,550) |
| Non-PEO NEO [Member] | Decrease for aggregate value for stock awards and option awards included in SCT for the covered fiscal year | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | (541,300) | (1,074,200) | |
| Non-PEO NEO [Member] | Increase for fair value at year end of awards granted during the covered fiscal year that were outstanding and unvested at the covered fiscal year end | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 469,000 | 970,425 | |
| Non-PEO NEO [Member] | Increase (decrease) in year-over-year change in fair value at covered fiscal year end of awards granted in any prior fiscal year that were outstanding and unvested at the covered fiscal year end | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | 84,825 | (42,640) | (35,254) |
| Non-PEO NEO [Member] | Increase (decrease) in change as of the vesting date (from the end of the prior fiscal year) in fair value of awards granted in any prior fiscal year for which vesting conditions were satisfied during the covered fiscal year | | | |
| Pay vs Performance Disclosure [Table] | | | |
| Adjustment to Compensation Amount | $ 65,534 | $ (6,835) | $ (35,388) |
