Income Taxes - Narrative (Details) - USD ($) shares in Millions				3 Months Ended								8 Months Ended	12 Months Ended
	May 24, 2019	Apr. 30, 2018	Apr. 12, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 03, 2017
Tax Credit Carryforward [Line Items]
Net loss, before income taxes				$ 125,740,000	$ 92,244,000	$ 64,059,000	$ 82,596,000	$ 86,404,000	$ 64,419,000	$ 51,250,000	$ 52,672,000	$ 114,374,000	$ 364,639,000	$ 254,745,000	$ 164,316,000
Income tax expense													0	0	0
Net operating loss carryforwards				188,200,000									188,200,000
Deferred tax assets, valuation allowance				214,853,000				126,562,000					214,853,000	126,562,000
Deferred tax liabilities, not available to offset deferred tax assets				1,800,000									1,800,000
Uncertain tax positions				0				$ 0				0	0	0	0
Related reserves				0									0
Decrease to deferred tax assets, Tax Cuts And Jobs Act Of 2017															9,300,000
Decrease to deferred tax assets, valuation allowance, Tax Cuts And Jobs Act Of 2017															9,300,000
Deferred tax liability, unrecorded, Tax Receivable Agreement				178,400,000									178,400,000
Car360
Tax Credit Carryforward [Line Items]
Deferred tax liability			$ 2,500,000
Deferred tax liability, amortization expense													$ 400,000	$ 300,000
Car360 | Minimum
Tax Credit Carryforward [Line Items]
Deferred tax liability, amortization period			2 years										2 years
Car360 | Maximum
Tax Credit Carryforward [Line Items]
Deferred tax liability, amortization period			7 years										7 years
Class A | Follow-On Offering
Tax Credit Carryforward [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	4.2	6.6
Class A | Over-Allotment Option
Tax Credit Carryforward [Line Items]
Sale of stock, option to purchase, number of additional shares (in shares)	0.6
Class A Units
Tax Credit Carryforward [Line Items]
Deferred tax assets, basis difference in acquired units		$ 2,500,000
Deferred tax assets, unrecorded													$ 30,600,000
Carvana Group
Tax Credit Carryforward [Line Items]
Deferred tax assets, basis difference in acquired units				$ 70,300,000									70,300,000
Carvana Group | Class A Units
Tax Credit Carryforward [Line Items]
Deferred tax assets, basis difference in acquired units	$ 7,500,000											$ 500,000			$ 500,000
Investment owned, balance (in shares)		8.3														18.8
Deferred tax assets, unrecorded	$ 42,700,000												$ 43,100,000
Exchange Agreement
Tax Credit Carryforward [Line Items]
Conversion of stock, converted (in shares)		6.9											5.4	14.2