Fair Value of Financial Instruments and Fair Value Measurements - Schedule of Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	$ 37,430	$ 52,427
Trading securities	24,924	13,508
Quoted Prices in Active Markets (Level 1)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	0	0
Trading securities	17,903	5,506
Significant Other Observable Inputs (Level 2)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	0	0
Trading securities	7,021	8,002
Significant Unobservable Inputs (Level 3)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	37,430	52,427
Trading securities	$ 0	$ 0