Segments Information - Depreciation and Amortization (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segments Information
Depreciation and amortization	$ 13,179	$ 8,382	$ 34,207	$ 22,819
Operating Segments
Segments Information
Depreciation and amortization	12,984	8,154	34,012	22,476
Corporate, Non-Segment
Segments Information
Depreciation and amortization	195	228	195	343
Consumer Services and Plans \| Operating Segments
Segments Information
Depreciation and amortization	951	888	2,546	2,889
Dealership \| Operating Segments
Segments Information
Depreciation and amortization	3,975	3,466	11,676	10,130
Retail \| Operating Segments
Segments Information
Depreciation and amortization	$ 8,058	$ 3,800	$ 19,790	$ 9,457

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Name:	us-gaap_DepreciationAndAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration