Income Taxes - Income Tax Uncertainties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, beginning	$ 383	$ 906	$ 1,127
Additions for prior year tax positions	0	0	41
Additions for current year tax positions	0	0	0
Lapse of statute of limitations	(188)	(497)	(248)
Reductions for tax positions of prior years	(13)	0	(14)
Settlements	0	(26)	0
Unrecognized tax benefits, ending	$ 182	$ 383	$ 906