Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Proceeds from grants	$ 1.6	$ 0.7	$ 4.4
LNG liquefaction plants | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
LNG liquefaction plants | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	20 years
Station equipment
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Other equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Other equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	7 years