Long-Lived Assets (Details 1) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Summary of carrying value of assets
Gross Carrying Amount, Client contracts	$ 151,493	$ 261,151
Client contracts, Accumulated Amortization	(82,743)	(184,763)
Client contracts, Net Amount	68,750	76,388
Gross Carrying Amount, Software	108,303	105,242
Software, Accumulated Amortization	(71,334)	(68,513)
Software, Net Amount	36,969	36,729
Gross Carrying Amount, Total	259,796	366,393
Accumulated Amortization, Total	(154,077)	(253,276)
Net Amount, Total	$ 105,719	$ 113,117

Accumulated amount of amortization of client contract assets.

No definition available.

Name:	csgs_ClientContractAccumulatedAmortization
Namespace Prefix:	csgs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before amortization of client contract assets.

+ References

No definition available.

+ Details

Name:	csgs_ClientContractsGross
Namespace Prefix:	csgs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, net of accumulated amortization of: (I) investments in client contracts; (II) direct and incremental costs that have been capitalized related to contractual arrangements where revenues have been deferred to convert or set-up client customers onto outsourced solutions; and (III) assets acquired in a business combination representing a favorable existing relationship with customers.

+ References

No definition available.

+ Details

Name:	csgs_ClientContractsNet
Namespace Prefix:	csgs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before amortization of software assets.

+ References

No definition available.

+ Details

Name:	csgs_SoftwareAccumulatedAmortization
Namespace Prefix:	csgs_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before amortization of software assets.

+ References

No definition available.

+ Details

Name:	csgs_SoftwareGross
Namespace Prefix:	csgs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, net of accumulated amortization, of (I) software and similar intellectual property rights from various business combinations; and (II) internal use software.

+ References

No definition available.

+ Details

Name:	csgs_SoftwareNet
Namespace Prefix:	csgs_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16323-109275

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration