| Cover | 12 Months Ended |
| Dec. 31, 2022 | |
| Document Information [Line Items] | |
| Document Type | DEF 14A |
| Amendment Flag | false |
| Entity Information [Line Items] | |
| Entity Registrant Name | CSG Systems International, Inc. |
| Entity Central Index Key | 0001005757 |
| Pay vs Performance Disclosure | 12 Months Ended | 24 Months Ended | 36 Months Ended | ||||||
| Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2022 | Dec. 31, 2022 | |||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Pay vs Performance [Table Text Block] | 2022 Pay versus Performance Pay versus Performance Table The following table contains additional compensation information of our current and former CEO (“CEO”) and non-CEO named executive officers (“NEOs”), along with total shareholder return (“TSR”), net income, and company-selected revenue measure results for our fiscal years ending in 2022, 2021, and 2020. This disclosure is intended to comply with the SEC rules under item 402(v) and does not necessarily reflect the Company’s approach to aligning compensation with performance. Additional information concerning the Company’s compensation philosophy and how the Company aligns compensation with financial performance can be found in the C ompensation Discussion and Analysis. Value of Initial Fixed $100 Investment Based On: Year (1) Summary Comp. Table Total for CEO Comp. Actually Paid to CEO (2)(3) Avg Summary Comp. Table Total for Non-CEO NEOs Avg Comp. Actually Paid to Non-CEO NEOs (2)(3) Company TSR (7) Peer Group TSR (7) GAAP Net Income Company Selected Measure “Revenue” 2022* $ 7,515,960 $ 7,019,416 (4) $ 2,153,261 $ 2,272,546 (4) $ 117.44 $ 73.35 $ 44,060,000 $ 1,089,752,000 2021 5,763,015 8,680,195 (5) 1,812,850 2,630,957 (5) 116.15 113.19 72,331,000 1,046,487,000 2020 14,037,609 8,821,747 (6) 3,049,302 3,155,018 (6) 89.00 140.11 58,711,000 990,533,000 *2022 compensation figures assume STIP at 58% of target, year-end stock price of $57.20 per share, and rTSR of $54.77 per share. (1) NEOs included in the above table are as follows: Year CEO Non-CEO NEOs 2022 Brian A. Shepherd Hai Tran, Kenneth M. Kennedy, Elizabeth A. Bauer, Rasmani Bhattacharya 2021 Brian A. Shepherd Hai Tran, Kenneth M. Kennedy, Elizabeth A. Bauer, Rolland B. Johns 2020 Bret C. Griess Rolland B. Johns, Kenneth M. Kennedy, Brian A. Shepherd (2) Fair Market Value (FMV) or change in fair value, as applicable, of equity awards was determined by reference to: (1) for restricted stock awards (excluding awards and other performance-based awards), closing price on applicable year-end date(s) or, in the case of vesting dates, the actual vesting price; (2) for performance-based restricted stock awards (excluding TSR awards), the same valuation methodology as restricted stock awards above except year-end values are multiplied times the probability of achievement as of each such date; (3) for TSR awards, the fair value calculated by a Monte Carlo simulation model as of the applicable year-end date(s), and in all cases based on volatility and risk free rates determined as of the revaluation date based on the expected life period and based on an expected dividend rate of 0%. (3) For the portion of compensation that is based on year-end stock prices, the following prices were used: (1) 2022 $57.20 (0.7% reduction from prior year); (2) 2021 $57.62 (27.8% increase from prior year); and (3) 2020 $45.07 (13.0% reduction from prior year). (4) 2022 compensation reflects the following adjustments from Total Compensation reported in the 2022 Summary Compensation Table: CEO Average Non-CEO NEO Total Reported in 2022 Summary Compensation Table $ 7,515,960 $ 2,153,261 Less, Value of Stock Awards Reported in SCT (5,986,094) (1,412,598) Plus, Year-End Value of Awards Granted in Fiscal Year that are Unvested and Outstanding 5,290,930 1,441,979 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested (149,222) (40,382) Plus, FMV of Awards Granted this Year and that Vested this Year - - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this Year 347,841 130,286 Less, Prior Year Fair Value of Prior Year awards that Failed to Vest this Year - - Total Adjustments (496,545) 119,285 Compensation Actually Paid for Fiscal Year 2022 $ 7,019,415 $ 2,272,546 (5) 2021 compensation reflects the following adjustments from Total Compensation reported in the 2021 Summary Compensation Table: CEO Average Non-CEO NEO Total Reported in 2021 Summary Compensation Table $ 5,763,015 $ 1,812,850 Less, Value of Stock Awards Reported in SCT (3,925,148) (1,065,208) Plus, Year-End Value of Awards Granted in Fiscal Year that are Unvested and Outstanding 4,682,547 1,270,751 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested 1,960,239 541,952 Plus, FMV of Awards Granted this Year and that Vested this Year - - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this year 199,542 70,612 Less, Prior Year Fair Value of Prior Year Awards that Failed to Vest this Year - - Total Adjustments 2,917,180 818,107 Compensation Actually Paid for Fiscal Year 2021 $ 8,680,195 $ 2,630,957 (6) 2020 compensation reflects the following adjustments from Total compensation reported in the 2020 Summary Compensation Table CEO Average Non-CEO NEO Total Reported in 2020 Summary Compensation Table $ 14,037,609 $ 3,049,302 Less, Value of Stock Awards Reported in SCT (12,163,565) (2,155,361) Plus, Year-End value of Awards Granted in Fiscal Year that are Unvested and Outstanding - 2,570,871 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested - (244,226) Plus, FMV of Awards Granted this Year and that Vested this Year 8,572,134 - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this Year (1,624,431) (65,568) Less Prior Year Fair Value of Prior Year Awards that Failed to Vest this Year - - Total Adjustments (5,215,862) 105,716 Compensation Actually Paid for Fiscal Year 2020 $ 8,821,747 $ 3,155,018 (7) Company TSR and our Standard Industrial Classification (“SIC”) Code Index: Computer Processing and Data Preparation and Processing Services, is as reflected in our 2022 Form 10-K pursuant to Item 201(e) of Regulation S-K. Each year reflects what the cumulative value of $100 would be, including reinvestment of dividends, if such amount were invested on December 31, 2019. | ||||||||
| Named Executive Officers, Footnote [Text Block] | (1) NEOs included in the above table are as follows: Year CEO Non-CEO NEOs 2022 Brian A. Shepherd Hai Tran, Kenneth M. Kennedy, Elizabeth A. Bauer, Rasmani Bhattacharya 2021 Brian A. Shepherd Hai Tran, Kenneth M. Kennedy, Elizabeth A. Bauer, Rolland B. Johns 2020 Bret C. Griess | ||||||||
| Peer Group Issuers, Footnote [Text Block] | (7) | ||||||||
| PEO Total Compensation Amount | $ 7,515,960 | $ 5,763,015 | $ 14,037,609 | ||||||
| PEO Actually Paid Compensation Amount | [1],[2] | 7,019,416 | [3] | 8,680,195 | [4] | 8,821,747 | [5] | ||
| Adjustment To PEO Compensation, Footnote [Text Block] | (4) 2022 compensation reflects the following adjustments from Total Compensation reported in the 2022 Summary Compensation Table: CEO Average Non-CEO NEO Total Reported in 2022 Summary Compensation Table $ 7,515,960 $ 2,153,261 Less, Value of Stock Awards Reported in SCT (5,986,094) (1,412,598) Plus, Year-End Value of Awards Granted in Fiscal Year that are Unvested and Outstanding 5,290,930 1,441,979 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested (149,222) (40,382) Plus, FMV of Awards Granted this Year and that Vested this Year - - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this Year 347,841 130,286 Less, Prior Year Fair Value of Prior Year awards that Failed to Vest this Year - - Total Adjustments (496,545) 119,285 Compensation Actually Paid for Fiscal Year 2022 $ 7,019,415 $ 2,272,546 (5) 2021 compensation reflects the following adjustments from Total Compensation reported in the 2021 Summary Compensation Table: CEO Average Non-CEO NEO Total Reported in 2021 Summary Compensation Table $ 5,763,015 $ 1,812,850 Less, Value of Stock Awards Reported in SCT (3,925,148) (1,065,208) Plus, Year-End Value of Awards Granted in Fiscal Year that are Unvested and Outstanding 4,682,547 1,270,751 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested 1,960,239 541,952 Plus, FMV of Awards Granted this Year and that Vested this Year - - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this year 199,542 70,612 Less, Prior Year Fair Value of Prior Year Awards that Failed to Vest this Year - - Total Adjustments 2,917,180 818,107 Compensation Actually Paid for Fiscal Year 2021 $ 8,680,195 $ 2,630,957 (6) 2020 compensation reflects the following adjustments from Total compensation reported in the 2020 Summary Compensation Table CEO Average Non-CEO NEO Total Reported in 2020 Summary Compensation Table $ 14,037,609 $ 3,049,302 Less, Value of Stock Awards Reported in SCT (12,163,565) (2,155,361) Plus, Year-End value of Awards Granted in Fiscal Year that are Unvested and Outstanding - 2,570,871 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested - (244,226) Plus, FMV of Awards Granted this Year and that Vested this Year 8,572,134 - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this Year (1,624,431) (65,568) Less Prior Year Fair Value of Prior Year Awards that Failed to Vest this Year - - Total Adjustments (5,215,862) 105,716 Compensation Actually Paid for Fiscal Year 2020 $ 8,821,747 $ 3,155,018 | ||||||||
| Non-PEO NEO Average Total Compensation Amount | 2,153,261 | 1,812,850 | 3,049,302 | ||||||
| Non-PEO NEO Average Compensation Actually Paid Amount | [1],[2] | $ 2,272,546 | [3] | 2,630,957 | [4] | 3,155,018 | [5] | ||
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | (4) 2022 compensation reflects the following adjustments from Total Compensation reported in the 2022 Summary Compensation Table: CEO Average Non-CEO NEO Total Reported in 2022 Summary Compensation Table $ 7,515,960 $ 2,153,261 Less, Value of Stock Awards Reported in SCT (5,986,094) (1,412,598) Plus, Year-End Value of Awards Granted in Fiscal Year that are Unvested and Outstanding 5,290,930 1,441,979 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested (149,222) (40,382) Plus, FMV of Awards Granted this Year and that Vested this Year - - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this Year 347,841 130,286 Less, Prior Year Fair Value of Prior Year awards that Failed to Vest this Year - - Total Adjustments (496,545) 119,285 Compensation Actually Paid for Fiscal Year 2022 $ 7,019,415 $ 2,272,546 (5) 2021 compensation reflects the following adjustments from Total Compensation reported in the 2021 Summary Compensation Table: CEO Average Non-CEO NEO Total Reported in 2021 Summary Compensation Table $ 5,763,015 $ 1,812,850 Less, Value of Stock Awards Reported in SCT (3,925,148) (1,065,208) Plus, Year-End Value of Awards Granted in Fiscal Year that are Unvested and Outstanding 4,682,547 1,270,751 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested 1,960,239 541,952 Plus, FMV of Awards Granted this Year and that Vested this Year - - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this year 199,542 70,612 Less, Prior Year Fair Value of Prior Year Awards that Failed to Vest this Year - - Total Adjustments 2,917,180 818,107 Compensation Actually Paid for Fiscal Year 2021 $ 8,680,195 $ 2,630,957 (6) 2020 compensation reflects the following adjustments from Total compensation reported in the 2020 Summary Compensation Table CEO Average Non-CEO NEO Total Reported in 2020 Summary Compensation Table $ 14,037,609 $ 3,049,302 Less, Value of Stock Awards Reported in SCT (12,163,565) (2,155,361) Plus, Year-End value of Awards Granted in Fiscal Year that are Unvested and Outstanding - 2,570,871 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested - (244,226) Plus, FMV of Awards Granted this Year and that Vested this Year 8,572,134 - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this Year (1,624,431) (65,568) Less Prior Year Fair Value of Prior Year Awards that Failed to Vest this Year - - Total Adjustments (5,215,862) 105,716 Compensation Actually Paid for Fiscal Year 2020 $ 8,821,747 $ 3,155,018 | ||||||||
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | Pay versus Performance Descriptive Disclosure We believe the compensation actually paid in each of the years reported above and over the three-year cumulative period are reflective of the Compensation Committee’s emphasis on “pay-for-performance” as it fluctuated year-over-year, primarily due to the result of our stock performance and our varying levels of achievement against pre-established performance goals under our annual performance bonus and our LTI program, including our revenue. Revenue continues to be our most important financial metric due to the following: ◼ Revenue growth is a critical part of our long-term strategic objectives. ◼ Our CEO and executive leadership team have set a long-term revenue target of $1.5 billion. ◼ Revenue or a related metric is included in both short-term and long-term incentive programs. (1) Total shareholder return in the above chart, in the case of both the Company and our Peer Companies as noted in footnote 7 of the above Pay for Performance Table, reflects the cumulative return of $100 as if invested on December 31, 2019, including reinvestment of any dividends. | ||||||||
| Compensation Actually Paid vs. Net Income [Text Block] | |||||||||
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | |||||||||
| Tabular List [Table Text Block] | Table of 3-7 Measures Most Important to Last Fiscal Year The following performance measures reflect the Company’s most important performance measures in effect for 2022, as further described and defined in Compensation Discussion and Analysis MOST IMPORTANT PERFORMANCE MEASURES FOR 2022 ◼ Revenue ◼ Non-GAAP Adjusted Revenue (Revenue Less Transaction Fees) ◼ Non-GAAP Adjusted Operating Margin Percentage ◼ Earnings Per Share ◼ TSR ◼ Impact Minutes | ||||||||
| Total Shareholder Return Amount | [6] | $ 117.44 | 116.15 | 89 | |||||
| Peer Group Total Shareholder Return Amount | [6] | 73.35 | 113.19 | 140.11 | |||||
| Net Income (Loss) | $ 44,060,000 | $ 72,331,000 | $ 58,711,000 | ||||||
| Company Selected Measure Amount | 1,089,752,000 | 1,046,487,000 | 990,533,000 | ||||||
| PEO Name | Bret C. Griess | Brian A. Shepherd | |||||||
| Measure [Axis]: 1 | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Measure Name | Revenue | ||||||||
| Measure [Axis]: 2 | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Measure Name | Non-GAAP Adjusted Revenue (Revenue Less Transaction Fees) | ||||||||
| Measure [Axis]: 3 | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Measure Name | Non-GAAP Adjusted Operating Margin Percentage | ||||||||
| Measure [Axis]: 4 | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Measure Name | Earnings Per Share | ||||||||
| Measure [Axis]: 5 | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Measure Name | TSR | ||||||||
| Measure [Axis]: 6 | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Measure Name | Impact Minutes | ||||||||
| PEO [Member] | Adjustment Type 1 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | $ (5,986,094) | $ (3,925,148) | $ (12,163,565) | ||||||
| PEO [Member] | Adjustment Type 2 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | 5,290,930 | 4,682,547 | |||||||
| PEO [Member] | Adjustment Type 3 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | (149,222) | 1,960,239 | |||||||
| PEO [Member] | Adjustment Type 5 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | 347,841 | 199,542 | (1,624,431) | ||||||
| PEO [Member] | Adjustment Type 6 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | (496,545) | 2,917,180 | (5,215,862) | ||||||
| PEO [Member] | Adjustment Type 4 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | 8,572,134 | ||||||||
| Non-PEO NEO [Member] | Adjustment Type 1 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | (1,412,598) | (1,065,208) | (2,155,361) | ||||||
| Non-PEO NEO [Member] | Adjustment Type 2 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | 1,441,979 | 1,270,751 | 2,570,871 | ||||||
| Non-PEO NEO [Member] | Adjustment Type 3 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | (40,382) | 541,952 | (244,226) | ||||||
| Non-PEO NEO [Member] | Adjustment Type 5 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | 130,286 | 70,612 | (65,568) | ||||||
| Non-PEO NEO [Member] | Adjustment Type 6 [Member] | |||||||||
| Pay vs Performance Disclosure [Table] | |||||||||
| Adjustment to Compensation Amount | $ 119,285 | $ 818,107 | $ 105,716 | ||||||
| [1] (2) (3) For the portion of compensation that is based on year-end stock prices, the following prices were used: (1) 2022 $57.20 (0.7% reduction from prior year); (2) 2021 $57.62 (27.8% increase from prior year); and (3) 2020 $45.07 (13.0% reduction from prior year). (4) 2022 compensation reflects the following adjustments from Total Compensation reported in the 2022 Summary Compensation Table: CEO Average Non-CEO NEO Total Reported in 2022 Summary Compensation Table $ 7,515,960 $ 2,153,261 Less, Value of Stock Awards Reported in SCT (5,986,094) (1,412,598) Plus, Year-End Value of Awards Granted in Fiscal Year that are Unvested and Outstanding 5,290,930 1,441,979 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested (149,222) (40,382) Plus, FMV of Awards Granted this Year and that Vested this Year - - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this Year 347,841 130,286 Less, Prior Year Fair Value of Prior Year awards that Failed to Vest this Year - - Total Adjustments (496,545) 119,285 Compensation Actually Paid for Fiscal Year 2022 $ 7,019,415 $ 2,272,546 (5) 2021 compensation reflects the following adjustments from Total Compensation reported in the 2021 Summary Compensation Table: CEO Average Non-CEO NEO Total Reported in 2021 Summary Compensation Table $ 5,763,015 $ 1,812,850 Less, Value of Stock Awards Reported in SCT (3,925,148) (1,065,208) Plus, Year-End Value of Awards Granted in Fiscal Year that are Unvested and Outstanding 4,682,547 1,270,751 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested 1,960,239 541,952 Plus, FMV of Awards Granted this Year and that Vested this Year - - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this year 199,542 70,612 Less, Prior Year Fair Value of Prior Year Awards that Failed to Vest this Year - - Total Adjustments 2,917,180 818,107 Compensation Actually Paid for Fiscal Year 2021 $ 8,680,195 $ 2,630,957 (6) 2020 compensation reflects the following adjustments from Total compensation reported in the 2020 Summary Compensation Table CEO Average Non-CEO NEO Total Reported in 2020 Summary Compensation Table $ 14,037,609 $ 3,049,302 Less, Value of Stock Awards Reported in SCT (12,163,565) (2,155,361) Plus, Year-End value of Awards Granted in Fiscal Year that are Unvested and Outstanding - 2,570,871 Plus, Change in Fair Value of any Prior Year Awards that are Outstanding and Unvested - (244,226) Plus, FMV of Awards Granted this Year and that Vested this Year 8,572,134 - Plus, Change in Fair Value (from Prior Year-End) of any Prior Year Awards that Vested this Year (1,624,431) (65,568) Less Prior Year Fair Value of Prior Year Awards that Failed to Vest this Year - - Total Adjustments (5,215,862) 105,716 Compensation Actually Paid for Fiscal Year 2020 $ 8,821,747 $ 3,155,018 (7) | |||||||||
