XML 105 R51.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Summary of Significant Accounting Policies - Advertising Expense and Manufacturing Cooperative Advertising Credits (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract] |  |  |
Advertising expense, gross | $ 139.8 | $ 134.2 | $ 116.1
Manufacturer cooperative advertising credits | (27.9) | (25.5) | (22.8)
Advertising expense, net | $ 111.9 | $ 108.7 | $ 93.3

X
- Definition Advertising Expense, Gross + References No definition available. + Details
Name: | lad_AdvertisingExpenseGross
Namespace Prefix: | lad_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 720 -SubTopic 35 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848 + Details
Name: | us-gaap_AdvertisingExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total amount received by an entity from a vendor under a cooperative advertising arrangement that has been offset against advertising expense. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 705 -SubTopic 20 -Section 25 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=68067574&loc=SL51760044-203187 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 720 -SubTopic 35 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848 + Details
Name: | us-gaap_CooperativeAdvertisingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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