Business Organization - Narrative (Details) $ / shares in Units, $ in Thousands				3 Months Ended	5 Months Ended	9 Months Ended
	Apr. 30, 2018 USD ($) $ / shares shares	Dec. 05, 2017 USD ($) $ / shares shares	May 03, 2017 USD ($) vote $ / shares shares	Sep. 30, 2018 $ / shares shares	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) $ / shares shares	Dec. 31, 2017 $ / shares shares
Subsidiary, Sale of Stock [Line Items]
Stock sold during period, net proceeds | $					$ 205,925
Preferred stock, shares authorized (in shares)			50,000,000.0	50,000,000		50,000,000	50,000,000
Preferred stock, par value (in dollars per share) | $ / shares			$ 0.01	$ 0.01		$ 0.01	$ 0.01
Conversion ratio						1.25
Carvana Group
Subsidiary, Sale of Stock [Line Items]
Ownership percentage by Carvana Co.				25.50%		25.50%
Ownership percentage by existing unitholders				74.50%		74.50%
Class A Common Units
Subsidiary, Sale of Stock [Line Items]
Conversion ratio				0.80		0.80
Class A Common Units | Carvana Group
Subsidiary, Sale of Stock [Line Items]
Convertible preferred stock, shares issued upon conversion (in shares)			43,100,000	4,800,000		4,800,000
Class A Common Units | Ernest Garcia, II
Subsidiary, Sale of Stock [Line Items]
Investment owned, balance (in shares)			200,000
Interest acquired			0.10%
Class A Common Units | Carvana Group
Subsidiary, Sale of Stock [Line Items]
Investment owned, balance (in shares)	8,300,000		18,800,000
LLC price per unit, multiple on initial public offering price less underwriting discounts and commissions			0.8
Follow-On Public Offering
Subsidiary, Sale of Stock [Line Items]
Stock sold during period, net proceeds | $						$ 172,287
Exchange Agreement
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, converted (in shares)	6,900,000					12,300,000
Class A
Subsidiary, Sale of Stock [Line Items]
Common stock, shares authorized (in shares)			500,000,000.0	500,000,000		500,000,000	500,000,000
Common stock, par value (in dollars per share) | $ / shares			$ 0.001	$ 0.001		$ 0.001	$ 0.001
Number of votes | vote			1
Issuance of Class A common stock sold in initial public offering, net of underwriters' discounts and commissions and offering expenses | $	$ 172,300
Class A | IPO
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)			15,000,000.0
Sale of stock, price per share (in dollars per share) | $ / shares			$ 15.00
Stock sold during period, net proceeds | $			$ 205,800
Issuance of Class A common stock sold in initial public offering, net of underwriters' discounts and commissions and offering expenses | $			$ 205,800
Class A | Follow-On Public Offering
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	6,600,000
Sale of stock, price per share (in dollars per share) | $ / shares	$ 27.50
Class A | Shares from Selling Stockholder and Selling LLC Unitholders
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)	6,100,000
Issuance of Class A common stock sold in initial public offering, net of underwriters' discounts and commissions and offering expenses | $	$ 0
Class A | Exchange Agreement
Subsidiary, Sale of Stock [Line Items]
Conversion ratio			0.8
Conversion of stock, issued (in shares)	5,600,000					9,800,000
Class B
Subsidiary, Sale of Stock [Line Items]
Common stock, shares authorized (in shares)			125,000,000.0	125,000,000		125,000,000	125,000,000
Common stock, par value (in dollars per share) | $ / shares			$ 0.001	$ 0.001		$ 0.001	$ 0.001
Number of votes | vote			1
Common stock, shares issued (in shares)			117,200,000
Conversion ratio			0.8
Class B | Garcia Parties
Subsidiary, Sale of Stock [Line Items]
Number of votes | vote			10
Class B | Exchange Agreement
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, converted (in shares)						8,900,000
Convertible Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Stock sold during period, net proceeds | $		$ 98,500
Preferred stock, shares authorized (in shares)		100,000		25,000		25,000	100,000
Preferred stock, par value (in dollars per share) | $ / shares		$ 0.01		$ 0.01		$ 0.01	$ 0.01
Conversion ratio		0.8
Preferred stock initial value per share (in dollars per share) | $ / shares		$ 1,000
Issuance of stock (in shares)		100,000
Convertible Preferred Stock | Carvana Group
Subsidiary, Sale of Stock [Line Items]
Sale of stock, number of shares issued in transaction (in shares)		100,000