Fair Value of Financial Instruments (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of intangible assets	$ 35,600	$ 0	$ 35,600	$ 0
Impairment losses	12,200	100	12,234	100
Contingent consideration					$ 6,200
Increase/(decrease) in contingent consideration value	600	$ 1,500	200	$ 1,100
Fair value adjustment of minority owned equity investment	4,300		6,600
Client lists
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of intangible assets	32,300		32,300
License
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of intangible assets	$ 3,300		$ 3,300
Myriad Development, Inc. & Insignificant Acquisition | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration					$ 20,500