Balance Sheet Items - Schedule of Accrued Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued expenses	$ 23,120	$ 20,456
Accrued payroll and bonuses	12,812	13,273
Accrued dividends	850	0	$ 0
Accrued interest	714	1,761
Accrued liabilities	$ 37,496	$ 35,490