Fair Value Measurements (Schedule of Fair Value of Assets and Liabilities not Subject to Fair Value Recognition) (Detail) $ in Thousands	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Assets
Notes receivable, Carrying Value	$ 52,081
Liabilities:
Convertible Notes Payable, Carrying Value	13,302	$ 27,250
December 2021 Notes [Member]
Liabilities:
Convertible Notes Payable, Carrying Value	12,402	$ 16,950
Fair Value Level 3 [Member]
Assets
Notes receivable, Fair Value	$ 57,279
Real estate appreciation [Member] \| Wellstat Diagnostics [Member]
Fair Value by Balance Sheet Grouping [Line Items]
Loans Held-for-sale, Measurement Input	0.00	0.00
Estimated realtor fee [Member] \| Wellstat Diagnostics [Member]
Fair Value by Balance Sheet Grouping [Line Items]
Loans Held-for-sale, Measurement Input	0.06	0.06
Minimum [Member] \| Measurement Input, Discount Rate [Member] \| Wellstat Diagnostics [Member]
Fair Value by Balance Sheet Grouping [Line Items]
Loans Held-for-sale, Measurement Input	0.12	0.12
Maximum [Member] \| Measurement Input, Discount Rate [Member] \| Wellstat Diagnostics [Member]
Fair Value by Balance Sheet Grouping [Line Items]
Loans Held-for-sale, Measurement Input	0.15	0.15

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Value of input used to measure loan, held for sale.

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Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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Fair value portion of an agreement for an unconditional promise by the maker to pay the holder a definite sum of money at a future date.

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