Income Taxes, Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Gross Unrecognized Tax Benefits [Roll Forward]
Beginning balance of unrecognized tax benefits	$ 69,784	$ 68,301	$ 78,014
Decrease for prior period tax positions	(24,154)	(867)	(12,814)
Increase for prior period tax positions	7,023	736	0
Increase for current period tax positions	1,510	1,614	3,101
Ending balance of unrecognized tax benefits	54,163	69,784	68,301
Unrecognized tax benefits that could impact effective tax rate, if recognized	6,400	400	0
Interest and penalties on unrecognized tax benefits	$ 300	$ 0	$ 0