Income Taxes - Unrecognized Tax Benefit Reconciliation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, beginning balance	$ 0	$ 216,000	$ 820,000
Increase attributable to tax positions taken during the current period	811,000		216,000
Decrease attributable to settlements with taxing authorities			(37,000)
Decrease attributable to lapse of statute of limitations			(783,000)
Decrease attributable to tax positions taken during a prior period		(216,000)
Unrecognized tax benefits, ending balance	$ 811,000	$ 0	$ 216,000