Fair Value Measurements and Investments - Schedule of Valuation Methodology and Unobservable Inputs for Level 3 Assets and Liabilities Measured at Fair Value (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Spinal Kinetics [Member] | Measurement Input Revenue Discount Rate
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Contingent consideration	$ 35,400
Spinal Kinetics [Member] | Measurement Input Revenue Discount Rate | Minimum [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Business combination contingent consideration liability measurement input	8.09
Spinal Kinetics [Member] | Measurement Input Revenue Discount Rate | Maximum [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Business combination contingent consideration liability measurement input	8.12
Spinal Kinetics [Member] | Measurement Input Payment Discount Rate | Minimum [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Business combination contingent consideration liability measurement input	3.83
Spinal Kinetics [Member] | Measurement Input Payment Discount Rate | Maximum [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Business combination contingent consideration liability measurement input	3.90
Spinal Kinetics [Member] | Measurement Input Projected Year Payment | Minimum [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Business combination contingent consideration liability measurement period	2021
Spinal Kinetics [Member] | Measurement Input Projected Year Payment | Maximum [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Business combination contingent consideration liability measurement period	2022
Neo Medical SA [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Neo Medical Convertible Loan	$ 7,160
Fair Value Inputs Implied Volatility	21.10%
Fair Value Inputs Discount Rate	108.10%