Organization and Summary of Significant Accounting Policies - Intangible Assets (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	$ 0	$ 0
Intangible assets, net	17,630,000	17,630,000
Sublicense agreement
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	11,330,000	11,330,000
Trademark license
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	6,030,000	6,030,000
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 270,000	$ 270,000