Income Taxes - Unrecognized Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Unrecognized Tax Benefit Activity [Roll Forward]
Beginning balance	$ 6,465	$ 5,315	$ 3,954
Additions based on tax positions related to the current year	0	0	1,087
Increases for tax positions of prior years	0	2,416	274
Statute of limitations expiration	0	(1,266)	0
Settlements	(3,322)	0	0
Ending balance	$ 3,143	$ 6,465	$ 5,315