Fair Value Measurements and Investments - Schedule of Change in Valuation of Securities (Detail) - Bone Biologics Inc [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Equity securities and warrants beginning balance	$ 219	$ 2,768	$ 2,768
Purchase of additional common stock	0	500	0
Fair value adjustments, expirations, and impairments recognized in other expense	0	(4,678)	0
Equity securities and warrants ending balance	219	219	2,768
ASU 2016-01 [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Impact of adoption of ASU 2016-01 recognized in other income	$ 0	$ 1,629	$ 0