Income Taxes - Unrecognized Income Tax Benefits (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Unrecognized Tax Benefits
Unrecognized tax benefits at beginning of the year	$ 2,400,000	$ 2,300,000	$ 800,000
(Reductions) additions for tax positions taken during the prior period	(600,000)	(100,000)
(Reductions) additions for tax positions taken during the prior period			900,000
Additions for tax positions taken during the current period	200,000	200,000	1,400,000
Reductions relating to settlements with taxing authorities	(100,000)		(800,000)
Unrecognized tax benefits at end of the year	$ 1,900,000	$ 2,400,000	$ 2,300,000