CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - UNAUDITED (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023
Statement of Cash Flows [Abstract]
Cash and settlement assets acquired	$ 46,432	$ 0

The cash and restricted cash/settlement assets associated with the acquisition of a business during the period.

No definition available.

Name:	csgs_CashAndRestrictedCashAcquiredFromAcquisition
Namespace Prefix:	csgs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration