Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized tax benefits, beginning of period	$ 121,715	$ 112,558	$ 56,702
Gross increase to positions in prior years	633	1,067	22,943
Gross decrease to positions in prior years	(2,140)	(3,296)	(24,949)
Gross increases to current period tax positions	14,821	13,762	63,869
Audit settlements	(795)	0	(2,977)
Decrease related to lapsing of statute of limitations	(2,381)	(1,574)	(1,368)
Effect of change in exchange rates	4,057	(802)	(1,662)
Unrecognized tax benefits, end of period	135,910	121,715	112,558
The amount of unrecognized tax benefits that, if recognized, would affect our effective tax rate	134,473	120,410	111,224
Net interest and penalties expense (benefit)	400	708	$ (990)
Accrued interest	3,432	2,849
Accrued penalties	$ 1,645	$ 1,681