Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Indefinite-lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 156,629
Finite-lived intangible assets, accumulated amortization	6,251
Galapagos operating licenses
Indefinite-lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	47,669	$ 11,600
Finite-lived intangible assets, accumulated amortization	$ 4,206	$ 3,700
Weighted Average Amortization Period (Years)	26 years	26 years 7 months 6 days