Fair Value of Financial Instruments and Fair Value Measurements - Level 3 Fair Value Measurements (Details)	Mar. 31, 2020	Dec. 31, 2019
Forecasted future revenue
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent revenue, measurement input		1,200,000,000
Forecasted future revenue | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent revenue, measurement input	900,000,000	1,100,000,000
Forecasted future revenue | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent revenue, measurement input	1,000,000,000
Stated royalty rate | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent revenue, measurement input	0.010	0.010
Stated royalty rate | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent revenue, measurement input	0.015	0.015
Annualized volatility | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent revenue, measurement input	0.124	0.094
Annualized volatility | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent revenue, measurement input	0.391	0.281
Annualized volatility | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent revenue, measurement input	0.250	0.199
Fair Value, Measurements, Recurring | Discounted cash flow | Debt securities payable | Significant Unobservable Inputs (Level 3) | Discount rate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt, measurement input	0.33	0.21
Line of Credit | Fair Value, Measurements, Recurring | Discounted cash flow | ABL Facility - due April 2022 | Significant Unobservable Inputs (Level 3) | Discount rate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Debt, measurement input	0.09