Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income tax expense	$ 33,588	$ 46,476
Effective tax rate	31.00%	24.00%
Federal statutory rate	21.00%	21.00%
Tax expense for excess tax deficiencies related to stock compensation	$ 4,600
Tax expense from foreign operations	4,000
State and local income tax expense	3,000	$ 3,200
Tax expense (benefit) from change in valuation allowance	2,700
Tax benefit relating to uncertain tax positions	2,800
Foreign tax credit carry forwards	30,300
Valuation allowance	28,900
Second component of tax deductible goodwill, net of tax	$ 300