Income Taxes - Components of Income Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Income Before Income Tax [Line Items]
Income Before Income Tax Expense	$ 392,482	$ 485,760	$ 383,896
United States [Member]
Schedule Of Income Before Income Tax [Line Items]
Income Before Income Tax Expense	359,496	449,171	379,407
Non-US [Member]
Schedule Of Income Before Income Tax [Line Items]
Income Before Income Tax Expense	$ 32,986	$ 36,589	$ 4,489