Income Taxes (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
Transition tax on foreign earnings			$ 96.4
Foreign tax credit related to withholding taxes			106.7
Change in state tax expense - remeasurement of deferred tax assets			$ 10.0
Transition tax, noncurrent liability	$ 66.1
Taxes Payable, Current	$ 7.8
Federal statutory rate	21.00%	21.00%	21.00%	35.00%
Federal income tax rate after enactment of Tax reform (Percentage)	21.00%
Effective Income Tax Rate Reconciliation, Tax Holiday, Amount		$ 17.3	$ 16.9
foreign withholding tax		$ 13.1	$ 60.7
Impact of tax holiday on diluted earnings per share		$ 0.15	$ 0.14
Liability for Uncertain Tax Positions, Noncurrent	$ 23.1
Change in state tax expense			$ 5.6
State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 86.8
Foreign [Member]
Income Taxes [Line Items]
Tax credit carryforward expiration	2028
Federal And State [Member]
Income Taxes [Line Items]
Operating Loss Carryforwards, Date	2021 through 2034