Fair Value Measurements (Schedule of Financial Assets Measured At Fair Value On A Nonrecurring Basis) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)
Assets:
Total expense for the year	$ 0	$ (88,438)	$ (97,785)	$ (253,886)
Fair value, measurements, nonrecurring
Assets:
Total expense for the year			(64,999)
Fair value, measurements, nonrecurring | Intangible assets
Assets:
Total expense for the year			(63,751)
Fair value, measurements, nonrecurring | Certain property, plant and equipment
Assets:
Total expense for the year			(1,248)
Level 1 Inputs | Fair value, measurements, nonrecurring
Assets:
Intangible assets, excluding goodwill	0		0
Certain property, plant and equipment	0		0
Total	0		0
Level 2 Inputs | Fair value, measurements, nonrecurring
Assets:
Intangible assets, excluding goodwill	0		0
Certain property, plant and equipment	0		0
Total	0		0
Level 3 Inputs | Fair value, measurements, nonrecurring
Assets:
Intangible assets, excluding goodwill	24,377		24,377
Certain property, plant and equipment	0		0
Total	$ 24,377		$ 24,377
Discount rate | Minimum | Fair value, measurements, nonrecurring
Assets:
Discount rate applied	0.100		0.100
Discount rate | Maximum | Fair value, measurements, nonrecurring
Assets:
Discount rate applied	0.120		0.120
Discount rate | Weighted average | Fair value, measurements, nonrecurring
Assets:
Discount rate applied	0.111		0.111