Fair Value Measurements - Common Stock Warrants (Details) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020 USD ($) $ / bbl shares	Dec. 31, 2019 $ / shares shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Weighted average exercise price (in usd per share) | $ / shares		$ 0.09
Term (years)		2 years 8 months 1 day
Fair value of common stock warrants (in usd per share) | $ / shares		$ 23.16
Warrants not settleable in cash, fair value | $	$ 3.9
Common stock, shares issued (in shares)	53,837,321	53,254,151
Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Common stock warrants outstanding (in shares)	0	354,350
Stock Issued During Period, Shares, Warrants Exercised	354,350
Common stock, shares issued (in shares)	350,542
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, price per barrel | $ / bbl	10.6
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, price per barrel | $ / bbl	26.2