Income Taxes - Components of Income Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Income Before Income Tax [Line Items]
Income Before Income Tax Expense	$ 478,725	$ 392,482	$ 485,760
United States [Member]
Schedule Of Income Before Income Tax [Line Items]
Income Before Income Tax Expense	407,015	359,496	449,171
Non-US [Member]
Schedule Of Income Before Income Tax [Line Items]
Income Before Income Tax Expense	$ 71,710	$ 32,986	$ 36,589