Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	$ 167.8
Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Amount	$ 11.8	$ 11.0
Statutory federal rate	21.00%	21.00%

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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