XML 58 R37.htm IDEA: XBRL DOCUMENT v3.10.0.1

Significant Accounting Policies - Summary of Revenue Disaggregated by Sales Channel and Major Products and Services (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation Of Revenue [Line Items]
Total revenues		$ 164,346	$ 169,312	$ 168,512	$ 159,957	$ 156,565	$ 159,899	$ 156,624	$ 153,174	$ 662,127	$ 626,262	$ 633,106
Direct
Disaggregation Of Revenue [Line Items]
Total revenues										457,651	333,248
National Advertising
Disaggregation Of Revenue [Line Items]
Total revenues										105,381	114,178
Other
Disaggregation Of Revenue [Line Items]
Total revenues										16,156	15,854
Retail
Disaggregation Of Revenue [Line Items]
Total revenues										579,188	463,280	462,776
Wholesale
Disaggregation Of Revenue [Line Items]
Total revenues	[1]									82,939	162,982	$ 170,330
Online Subscription Advertising
Disaggregation Of Revenue [Line Items]
Total revenues										507,993	483,026
Display Advertising
Disaggregation Of Revenue [Line Items]
Total revenues										112,792	102,183
Pay Per Lead
Disaggregation Of Revenue [Line Items]
Total revenues										30,757	31,727
Other
Disaggregation Of Revenue [Line Items]
Total revenues										$ 10,585	$ 9,326
[1] For information related to related party transactions, see Note 15 (Related Party).

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

X

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

+ Details

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_ContractWithCustomerSalesChannelAxis=us-gaap_SalesChannelThroughIntermediaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ContractWithCustomerSalesChannelAxis=cars_SalesChannelThroughNationalAdvertisingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ContractWithCustomerSalesChannelAxis=cars_SalesChannelThroughOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ContractWithCustomerSalesChannelAxis=cars_SalesChannelThroughRetailMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ContractWithCustomerSalesChannelAxis=cars_SalesChannelThroughWholesaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=cars_OnlineSubscriptionAdvertisingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=cars_DisplayAdvertisingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=cars_PayPerLeadMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=cars_OtherMajorProductAndServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: