Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Contingency [Line Items]
Effective income tax rate	12.00%	30.00%	11.60%	31.20%
Goodwill, Impairment Loss	$ 379,863	$ 0	$ 379,863	$ 0
Goodwill Yielding Permanent Differences Between Book Income And Taxable Income	209,500		209,500
Goodwill Impairment Tax Benefit	$ 50,400		50,400
Amount recorded as deferred tax asset / reduction of previously recorded deferred tax liability			$ 50,400
Excluding Impact Of Goodwill Impairment Charge [Member]
Income Tax Contingency [Line Items]
Effective income tax rate	34.70%		34.00%