Minimum quarterly dividends to adjust conversion rate.

No definition available.

Name:	csgs_MinimumQuarterlyDividendsToAdjustConversionRate
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Balance Type:	na
Period Type:	instant

- Definition

The percentage amount of the par value of debt that will be settled in cash.

+ References

No definition available.

+ Details

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Namespace Prefix:	csgs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

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Balance Type:	na
Period Type:	instant

- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

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-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instruments must exceed threshold percentage for a specified number of trading days to trigger conversion feature, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value amount of debt instrument that was repurchased.

+ References

No definition available.

+ Details

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

- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

+ Details

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

- Definition

Amount of debt discount to be amortized after one year or the normal operating cycle, if longer.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

+ References

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-Publisher FASB
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Debt - 2016 Convertible Notes (Details Textual) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) Tradingday $ / shares	Dec. 31, 2015 USD ($)	Mar. 31, 2016 USD ($)	Mar. 15, 2016 USD ($)
Debt Instrument [Line Items]
Proceeds from long-term debt	$ 230,000	$ 150,000
Long-term debt, unamortized original issue discount	$ 23,007	$ 4,738
Senior Convertible Notes 2016
Debt Instrument [Line Items]
Senior convertible notes face amount			$ 230,000
Interest rate on senior convertible notes	4.25%		4.25%
Maturity date of 2016 convertible Notes	Mar. 15, 2036
Initial conversion rate of common stock	17.4642
Convertible Notes, initial conversion of Par Value Convertible Notes to common stock	$ 1
Initial conversion price \| $ / shares	$ 57.26
Minimum quarterly dividends to adjust conversion rate \| $ / shares	$ 0.185
Percentage of par value of convertible notes to be settled in cash	100.00%
Rate of conversion price	130.00%
Debt instrument, convertible, threshold consecutive trading days	20 days
Debt instrument, convertible, threshold trading days \| Tradingday	30
Proceeds from long-term debt	$ 223,000
Long-term debt, unamortized original issue discount	$ 14,005			$ 15,900
Effective interest rate of the liability	5.63%
2010 Convertible Notes Repurchased
Debt Instrument [Line Items]
Aggregate principal amount of convertible notes repurchased	$ 115,000
Amount paid to purchase aggregate principal amount	$ 215,600