- Fair Value Measurements (Schedule of Financial Assets Measured At Fair Value On A Nonrecurring Basis) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Assets:
Total expense for the year	$ (165,448)	$ (448,416)
Fair value, measurements, nonrecurring
Assets:
Total expense for the year	(79,448)
Fair value, measurements, nonrecurring | Intangible assets
Assets:
Total expense for the year	(78,700)
Fair value, measurements, nonrecurring | Certain property, plant and equipment
Assets:
Total expense for the year	(748)
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair value, measurements, nonrecurring
Assets:
Intangible assets, excluding goodwill	0
Certain property, plant and equipment	0
Total	0
Significant Other Observable Inputs (Level 2) | Fair value, measurements, nonrecurring
Assets:
Intangible assets, excluding goodwill	0
Certain property, plant and equipment	0
Total	0
Significant Unobservable Inputs (Level 3) | Fair value, measurements, nonrecurring
Assets:
Intangible assets, excluding goodwill	41,839
Certain property, plant and equipment	0
Total	$ 41,839