Income Taxes, Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Gross Unrecognized Tax Benefits [Roll Forward]
Beginning balance of unrecognized tax benefits	$ 68,301	$ 78,014	$ 66,999
Decrease for prior period tax positions	(867)	(12,814)	0
Increase for prior period tax positions	736	0	1,520
Increase for current period tax positions	1,614	3,101	9,495
Ending balance of unrecognized tax benefits	69,784	$ 68,301	$ 78,014
Unrecognized tax benefits that could impact effective tax rate, if recognized	21,700
Interest and penalties on unrecognized tax benefits	$ 0