Debt - 7.5% Notes (Details) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended		12 Months Ended
	May 05, 2020 USD ($)	Jun. 30, 2013 USD ($) D $ / shares	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2019 USD ($)
Long-term debt [Line Items]
Amount of advance funded			$ 200	$ 3,394
Aggregate principal amount			$ 87,771			$ 89,094
7.5% Notes
Long-term debt [Line Items]
Interest rate		7.50%	7.50%			7.50%
Debt issuance amount		$ 150,000
Conversion price of shares (in dollars per share) | $ / shares		$ 15.80
Percentage of the trade price of common stock that the conversion price must be at premium for the Company to force conversion		40.00%
Number of days within 30 consecutive trading days in which the trade price of the entity's common stock must be at premium of the conversion price for the Company to force conversion | D		20
Number of consecutive trading days used to determine the conversion obligation on the notes for the Company to force conversion | D		30
Aggregate principal amount			$ 50,000			$ 50,000
7.5% Notes | Subsequent Event
Long-term debt [Line Items]
Repayments of debt	$ 35,000
7.5% Notes | Green Energy Investment Holdings, LLC
Long-term debt [Line Items]
Principal amount transferred					$ 16,800
Aggregate principal amount			32,900
7.5% Notes | Mr. Pickens
Long-term debt [Line Items]
Repurchased face amount during period					$ 25,000
7.5% Notes | Other Third Parties
Long-term debt [Line Items]
Aggregate principal amount			$ 17,100