Business Segment Information Business Segment Information (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended	48 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2022
Segment Reporting Information [Line Items]
Asset Write-Offs, Impairments, And Related Charges	$ 68,943	$ 193,571	$ 141,867	$ 405,362
Restructuring Charges	34,000	42,000	60,000	66,000
Employee Retention and Severances Expenses and Other Benefits-Related Costs [Member]
Segment Reporting Information [Line Items]
Restructuring Charges	$ 34,000	$ 42,000	$ 60,000	$ 66,000
Employee Retention and Severances Expenses and Other Benefits-Related Costs [Member] | Subsequent Event [Member]
Segment Reporting Information [Line Items]
Restructuring Charges					$ 155,000	$ 215,000