Income Taxes - Uncertain Tax Positions Reconciliation (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]
Balance at January 1	$ 291	$ 223	$ 257
Additions (reductions) for tax positions of prior years	(6)		(3)
Additions (reductions) for tax positions of prior years		68
Additions (reductions) for tax positions of current year	0
Reductions for settlements with tax authorities		0	0
Reductions for lapse of statute of limitations	(72)	0	(31)
Balance at December 31	$ 213	$ 291	$ 223