Assets and Liabilities Measured at Fair Value (Narratives) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	[1]
Impairment of assets	$ 20,000,000	$ 0	$ 95,088,000
Contingent Consideration Liability [Member]
Fair value assumptions, expected term	7 years
Fair value assumptions, expected volatility rate	30.00%
Fair value assumptions	2.752%

[1] Reclassified to conform to current presentation (see Note B).