XML 36 R88.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

EMPLOYEE BENEFIT PLANS (Information Regarding Stock Options) (Details) | 12 Months Ended
--- | ---
Dec. 31, 2019 $ / shares shares
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract] |
Number of shares (in shares) | shares | 275,658
Weighted- average exercise price (in dollars per share) | $ 267.23
Options Exercisable [Abstract] |
Number of shares (in shares) | shares | 147,620
Weighted-average exercise price (in dollars per share) | $ 210.96
$102.16 - $142.45 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Range of exercise price, minimum, (in dollars per share) | 102.16
Range of exercise price, maximum, (in dollars per share) | $ 142.45
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract] |
Number of shares (in shares) | shares | 3,522
Weighted-average remaining contractual life (in years) | 3 years 2 months 8 days
Weighted- average exercise price (in dollars per share) | $ 102.16
Options Exercisable [Abstract] |
Number of shares (in shares) | shares | 3,522
Weighted-average exercise price (in dollars per share) | $ 102.16
$142.46 - $188.22 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Range of exercise price, minimum, (in dollars per share) | 142.46
Range of exercise price, maximum, (in dollars per share) | $ 188.22
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract] |
Number of shares (in shares) | shares | 36,600
Weighted-average remaining contractual life (in years) | 6 years 2 months 8 days
Weighted- average exercise price (in dollars per share) | $ 182.75
Options Exercisable [Abstract] |
Number of shares (in shares) | shares | 36,600
Weighted-average exercise price (in dollars per share) | $ 182.75
$188.23 - $197.37 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Range of exercise price, minimum, (in dollars per share) | 188.23
Range of exercise price, maximum, (in dollars per share) | $ 197.37
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract] |
Number of shares (in shares) | shares | 32,200
Weighted-average remaining contractual life (in years) | 5 years 2 months 1 day
Weighted- average exercise price (in dollars per share) | $ 193.69
Options Exercisable [Abstract] |
Number of shares (in shares) | shares | 32,200
Weighted-average exercise price (in dollars per share) | $ 193.69
$197.38 - $202.98 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Range of exercise price, minimum, (in dollars per share) | 197.38
Range of exercise price, maximum, (in dollars per share) | $ 202.98
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract] |
Number of shares (in shares) | shares | 33,600
Weighted-average remaining contractual life (in years) | 4 years 1 month 28 days
Weighted- average exercise price (in dollars per share) | $ 201.04
Options Exercisable [Abstract] |
Number of shares (in shares) | shares | 33,600
Weighted-average exercise price (in dollars per share) | $ 201.04
$202.99 - $273.52 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Range of exercise price, minimum, (in dollars per share) | 202.99
Range of exercise price, maximum, (in dollars per share) | $ 273.52
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract] |
Number of shares (in shares) | shares | 52,135
Weighted-average remaining contractual life (in years) | 7 years 1 month 28 days
Weighted- average exercise price (in dollars per share) | $ 204.91
Options Exercisable [Abstract] |
Number of shares (in shares) | shares | 23,066
Weighted-average exercise price (in dollars per share) | $ 204.91
$273.53 - $370.14 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Range of exercise price, minimum, (in dollars per share) | 273.53
Range of exercise price, maximum, (in dollars per share) | $ 370.14
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract] |
Number of shares (in shares) | shares | 69,301
Weighted-average remaining contractual life (in years) | 8 years 1 month 28 days
Weighted- average exercise price (in dollars per share) | $ 342.13
Options Exercisable [Abstract] |
Number of shares (in shares) | shares | 18,632
Weighted-average exercise price (in dollars per share) | $ 342.13
$370.15 - $398.15 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Range of exercise price, minimum, (in dollars per share) | 370.15
Range of exercise price, maximum, (in dollars per share) | $ 398.15
Share-based Payment Arrangement, Option, Exercise Price Range, End of Period [Abstract] |
Number of shares (in shares) | shares | 48,300
Weighted-average remaining contractual life (in years) | 9 years 1 month 6 days
Weighted- average exercise price (in dollars per share) | $ 398.15
Options Exercisable [Abstract] |
Number of shares (in shares) | shares | 0
Weighted-average exercise price (in dollars per share) | $ 0

X
- References No definition available. + Details
Name: | csgp_OptionsExercisableAbstract
Namespace Prefix: | csgp_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeEndOfPeriodAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(iii) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iii) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=csgp_ExerciseRange1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=csgp_ExerciseRange2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=csgp_ExerciseRange3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=csgp_ExerciseRange4Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=csgp_ExerciseRange5Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=csgp_ExerciseRange6Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis=csgp_ExerciseRange7Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |