Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Total unrecognized tax benefits at January 1	$ 0	$ 0	$ 0
Gross amount of increases for prior years' tax positions	469	0	0
Total unrecognized tax benefits at December 31	$ 469	$ 0	$ 0