Stockholders' Equity - Convertible Preferred Stock (Details) $ / shares in Units, $ in Thousands			3 Months Ended		12 Months Ended
	Dec. 11, 2017	Dec. 05, 2017 USD ($) $ / shares shares	Mar. 31, 2019 USD ($) $ / shares shares	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($) $ / shares shares	Jan. 29, 2018 $ / shares	May 03, 2017 $ / shares
Limited Partners' Capital Account [Line Items]
Preferred stock, par value (in dollars per share) | $ / shares			$ 0.01		$ 0.01		$ 0.01
Conversion ratio			1.25
Accretion of beneficial conversion feature on Class A convertible preferred stock			$ 0	$ (1,380)
Dividends paid			$ 0	1,528
Preferred stock, shares outstanding (in shares) | shares			0		0
Class A Common Units
Limited Partners' Capital Account [Line Items]
Conversion ratio			0.80
Carvana Group | Class A Common Units
Limited Partners' Capital Account [Line Items]
Conversions of Class A Convertible Preferred Stock (in shares) | shares					6,300,000
Convertible Preferred Stock
Limited Partners' Capital Account [Line Items]
Issuance of stock (in shares) | shares		100,000
Gross issuance of stock		$ 100,000
Stock sold during period, net proceeds		$ 98,500
Preferred stock, par value (in dollars per share) | $ / shares		$ 0.01
Preferred stock initial value per share (in dollars per share) | $ / shares		1,000
Conversion rate (in dollars per share) | $ / shares		$ 19.6945				$ 50.78
Percent of stock price for company option to convert preferred stock to common		150.00%
Conversion ratio		0.8
Redemption price, calculation premium to volume weighted average stock price		20.00%
Beneficial conversion feature of Class A convertible preferred stock		$ 2,600
Redemption price, trading days used In calculation	5 days
Accretion of beneficial conversion feature on Class A convertible preferred stock				1,400
Dividends paid				1,500
Preferred stock, shares outstanding (in shares) | shares			0		0
Accrued dividends			$ 0		$ 0
Convertible Preferred Stock | Shareholder
Limited Partners' Capital Account [Line Items]
Conversions of Class A Convertible Preferred Stock (in shares) | shares					75,000
Convertible Preferred Stock | Carvana Group
Limited Partners' Capital Account [Line Items]
Sale of stock, number of shares issued in transaction (in shares) | shares		100,000
Dividends paid				$ 1,500
Conversions of Class A Convertible Preferred Stock (in shares) | shares					25,000
Class A Common Stock
Limited Partners' Capital Account [Line Items]
Conversions of Class A Convertible Preferred Stock (in shares) | shares					5,100,000