Balance Sheet Components - Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020		Dec. 31, 2019		Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Delaware grant	$ 9,212		$ 10,469
Other	17,406		17,544
Other long-term liabilities	$ 26,618	[1]	$ 28,013	[1]	$ 28,852

[1] We have variable interest entities, which represent a portion of the consolidated balances recorded within these financial statement line items in the condensed consolidated balance sheets (see Note 13, Power Purchase Agreement Programs).