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Fair Value Measurements (Details Textual) - USD ($)	3 Months Ended
Fair Value Measurements (Details Textual) - USD ($)	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Business Acquisition, Contingent Consideration [Line Items]
Asset impairment charges	$ 0
Fair value measurements, changes in valuation inputs	0
Contingent consideration obligations	194,200,000		$ 197,700,000
Contingent consideration impairment	4,600,000	$ (11,500,000)
Future payment	$ 0	$ 0
2.900% Senior Notes due 2020
Business Acquisition, Contingent Consideration [Line Items]
Senior Notes interest rate	2.90%
3.625% Senior Notes due 2022
Business Acquisition, Contingent Consideration [Line Items]
Senior Notes interest rate	3.625%
4.050% Senior Notes due 2025
Business Acquisition, Contingent Consideration [Line Items]
Senior Notes interest rate	4.05%
5.200% Senior Notes due 2045
Business Acquisition, Contingent Consideration [Line Items]
Senior Notes interest rate	5.20%